(17 8 pages)



### COMMITTEE ON AVIATION ENVIRONMENTAL PROTECTION (CAEP)

EIGHTH MEETING

Montréal, 1 to 12 February 2010



### AGENDA ITEM 2

The attached constitutes Appendices B, C and D to the report on Agenda

Item 2 a nd should be inserted at the appropriate place in the yellow

folder. CAEP/8

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APPENDIX B

ICAO Emissions Environmental Technical Manual

Volume II

Guidelines on the use of procedures in the Emissions certification of aircraft enginesCAEP/8

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# Environmental Technical Manual

V olume II

G uidelines on the U se of P rocedures in the

E mi ssions C ertification of A ircraft E nginesCAEP/8

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TABLE OF CONTENTS

Page No.

Nomenclature

................................ ................................ ................................ ................................ ........

Section 1. Introduction

1.1 Purpose

1.2 Framework

................................ ................................ ................................ ................................ . 1.3 Emissions compliance demonstration plans

................................ ................................ ............... 1.4 Emissions certification reports

................................ ................................ ................................ ...

Section 2. Guid ance material

Part I. Definitions and Symbols

................................ ................................ ................................ ............

Part II. Vented Fuel [Reserved]

................................ ................................ ................................ ..............

Part III. Emissions Certification

................................ ................................ ................................ ..............

Chapter 1. Administration [Reserved]

................................ ................................ .........................

Chapter 2. Turbo

jet and turbofan engines intended for propulsion only at subsonic speeds

................................ ................................ ............

2.1 General

................................ ................................ ................................ .......................... 2.1.1 Applicability

................................ ................................ ................................ .................. 2.1.2 Emissions involved [Reserved]

................................ ................................ ..................... 2.1.3 Units of measurement

................................ ................................ ................................ .... 2.1.4 Reference conditions

................................ ................................ ................................ ..... 2.1.4.1 Atmospheric conditions

................................ ................................ ................................ . 2.1.4.2 Thrust settings [Reserved]

................................ ................................ ............................. 2.1.4.3 Reference emissions landing and take

- off (LTO) cycle

................................ ................................ ................................ ................... 2.1.4.4 Fuel specification

................................ ................................ ................................ .......... 2.1.5 Test conditions [Reserved]

................................ ................................ ............................

2.2 Smoke

................................ ................................ ................................ ............................ 2.2.1 Applicability [Reserved]

................................ ................................ ............................... 2.2.2 Regulatory smoke number [Reserved]

................................ ................................ ..........

2.3 Gaseous emissions

................................ ................................ ................................ ......... 2.3.1 Applicability [Reserved]

................................ ................................ ............................... 2.3.2 Regulatory levels

................................ ................................ ................................ ...........

2.4 Information required

................................ ................................ ................................ ...... 2.4.1 General information [Reserved]

................................ ................................ .................... 2.4.2 Test information [Reserved]

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2.4.3 Derived information

................................ ................................ ................................ ......

Chapter 3. Turbo

-

jet and turbofan engines intended fo r propulsion at supersonic speeds [Reserved]

................................ ................................ ....

Appendix 1. Measurement of reference pressure ratio [Reserved]

................................ ..............

Appendix 2. Smoke emission evaluation

................................ ................................ .........................

1. Introduction and definitions [Reserved]

................................ ................................ ..............

2. Measurement of smoke emissions

................................ ................................ ....................... 2.1 Sampling probe for smoke emissions

................................ ................................ .................. 2.2 Sampling line for smoke emissions

................................ ................................ ..................... 2.3 Smoke analysis system

................................ ................................ ................................ ........ 2.4 Fuel specifications

................................ ................................ ................................ ............... 2.5 Smoke measurement procedures

................................ ................................ .......................... 2.5.1 Engine operation

................................ ................................ ................................ .................. 2.5.2 Leakage and cleanliness checks

................................ ................................ ........................... 2.5.3 Sm oke measurement

................................ ................................ ................................ ............

3. Calculation of smoke number from measured data

................................ .............................

4. Reporting of data to the certificating authority [Reserved]

................................ .................

Appendix 3. Instrumentation and measurement techniques

for gaseous emissions

................................ ................................ ................................ ...

1. Introduction

................................ ................................ ................................ ..........................

2. Definitions [Reserved]

................................ ................................ ................................ .........

3. Data required

................................ ................................ ................................ ........................ 3.1 Gaseous emissions

................................ ................................ ................................ ............... 3.2 Other information [Reserved]

................................ ................................ ..............................

4. General arrangement of the system

................................ ................................ ......................

5. Description of component parts

................................ ................................ ........................... 5.1 Sampling system

................................ ................................ ................................ .................. 5.1.1 Sampling probe

................................ ................................ ................................ .................... 5.1.2 Sampling lines [Reserved]

................................ ................................ ................................ ... 5.2 HC analyser [Reserved]

................................ ................................ ................................ ....... 5.3 CO and CO 2 analysers [Reserved]

................................ ................................ ....................... 5.4 NO X analysers [Reserved]

................................ ................................ ................................ ...

6. General test procedures

................................ ................................ ................................ ........ 6.1 Engine operation [Reserved]

................................ ................................ ................................ 6.2 Major instrument calibration [Reserved]

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6.3 Operation [Reserved]

................................ ................................ ................................ ........... 6.4 Carbon balance check [Reserved]

................................ ................................ ........................

7. Calculations

................................ ................................ ................................ ......................... 7.1 Gaseous emissions [Reserved]

................................ ................................ ............................. 7.1.1 General [Reserved]

................................ ................................ ................................ .............. 7.1.2 Basic parameters [Reserved]

................................ ................................ ................................ 7.1.3 Correction of emissions indices to reference condi tions [Reserved]

................................ ... 7.2 Control parameter functions [Reserved]

................................ ................................ .............. 7.3 Exceptions to the proposed procedures [Reserved]

................................ .............................

Attachment A to Appendix 3. Specification for HC analyser

................................ .....................

1. General

................................ ................................ ................................ ................................ . 2. Synergistic effects

................................ ................................ ................................ ................ 3. Optimization of d etector response and alignment

................................ ................................

Appendix 4. Speci fication for fuel to be used in

aircraft turbine engine emission testing

................................ ................................ ....

Appendix 5. Instrumentation and measurement techniques for gaseous

emissions from afterburning gas turbine engines [R eserved]

................................ .

Appendix 6. Compliance procedures for

Gaseous emissions and smoke [Reserved]

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NOMENCLATURE

Symbols and Units

Symbols and abbreviations employed in Volume II of this manual are consistent with those contained in

Annex 16

– Environment al Protection , Volume II

– Aircraft Engine Emissions (Third Edition, July 2008)

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## SECTION 1. INTRODUCTION

1.1 PURPOSE

1.1.1 The aim of Volume II of this manual is to promote uniformity in the implementation of

ICAO Annex 16

— Environmental Protection , Volume II

— Aircraft Engine Emissions , by providing guidance to certificating authorities and applicants regarding the intended meaning of the current

Annex 16, Volume II e missions Standards and those specific procedures that are deemed acceptable in demonstrating compliance to these Standards.

1.1.2 This manual also provides guid ance in the wider application of equivalent procedures that have been accepted as a technical means for demonstrating compliance with the emissions certification requirements of Annex 16, Volume II. Such equivalent procedures are referred to in Annex 16,

V olume II, but are not dealt with in the same detail as in the Appendices which describe the emissions evaluation methods for compliance with the relevant Chapters of Annex 16, Volume II.

1.1.3 Annex 16, Volume II procedures must be used unless an equival ent procedure is approved by the certificating authority. Procedures presented in this manual should not be considered as limited only to those described herein as this manual will be expanded as new procedures are developed. Also, their presentation does not infer limitation of their application or commitment by certificating

authorities to their further use.

1.1.4 References to Annex 16, Volume II relate to the Amendment 6 thereof.

1.2 FRAMEWORK

1.2.1 The basic framework of Volume II of this manual is a replication of the ICAO Annex 16, Volume II structure in order to ensure easy reference between the requirements and guidance. References in the Table of Contents are only made to a part of the requirements when there is an associated guidance

materi al; otherwise the relevant paragraph has b een ―Reserved‖ for future use. There is minimal repetition of the requirement text in order to simplify the ETM content, lower maintenance costs, and reduce the danger of inconsistencies between Volume II and the E TM following future revisions. The requirement

text is enclosed between two horizontal lines.

1.2. 2 This first s ection provides general information while the second Section contains guidance material to ICAO Annex 16, Volume II. The format of the guidanc e material includes three types of information described as e xplanatory i nformation, e quivalent p rocedures and t echnical

p rocedures. The d efinitions of these three types of information are as follows:

Explanatory information

• Explains ICAO Annex 16 e missions Standards language

.

• States current policies of regulatory authorities regarding compliance with ICAO

Annex 16 e missions Standards

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• Provides awareness of critical issues for approval of applicants‘ compliance methodology proposals

.

Equivale nt procedures

• An equivalent procedure is a test or analysis procedure which, while differing from one specified in Annex 16

, Volume II, in the technical judgement of the certificating authority

, yields effectively the same emissions levels as the specif ied procedure.

• The use of equivalent procedures may be requested by applicants for many reasons, including:

a) to make use of previously acquired certification test data for the engine type; and

b) to minimize the costs of demonstrating compliance wi th the requirements of ICAO Annex 16, Volume II by keeping engine test time, test bed usage, and equipment and personnel costs to a minimum.

Technical procedures

• A technical procedure is a test or analysis procedure not defined in detail in ICAO

Ann ex 16 e missions Standards but which certificating authorities have approved as being acceptable for compliance with the general provisions the e missions Standards specify.

1.3 EMISSIONS COMPLIANCE DEMONSTRATION PLAN

1.3.1 Prior to undertaking an emissi ons certification demonstration, the applicant is normally required to submit to the certificating authority an emissions compliance demonstration plan. This plan contains the method by which the applicant proposes to show compliance with the emissions

req uirements. Approval of this plan and the proposed use of any equivalent procedure remain with the certificating authority. The determination of equivalency for any procedure or group of procedures must be based upon the consideration of all pertinent facts relating to the application.

1.3.2 Emissions compliance demonstration plans should include the following types of

information:

a) Introduction: description of the engine emissions certification basis, i.e. the applicable

Annex 16, Volume II Amendment and Chapter ;

b) E ngine description: type, model number and specific details of the basic configuration to

be certified ;

c) E ngine emissions certification methodology: test concepts, equivalent procedures and technical procedures ;

d) T est description: test methods to comply with the emissions S tandards ;CAEP/8

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e) M easurement system: description of measurement and sampling system components and procedures, including calibration procedures, that are intended to be used to demonstrate compliance with the emiss ions S tandards ; and

f) D ata evaluation procedures: e missions evaluation and adjustment procedures (including equivalent and technical procedures such as those provided in this manual) to be used in compliance with the provisions of ICAO Annex 16, Volume II appropriate to the engine type being certificated

.

1.4 EMISSIONS CERTIFICATION REPORTS

1.4.1 Following completion of an emissions certification demonstration test, an applicant is normally required to submit an emissions certification report. This report provides a complete description of the test process and the test results with respect to compliance with the provisions of Annex 16,

Volume II.

1.4.2 These reports should include the following types of information:

a) B asis for test approval : th e approved emissions certification compliance plan for the engine ty pe and model being certificated;

b) D escription of tests : actual configurations tested and non

- conforming items (with justification that they are not significant to emissions, or if sign ificant, can be dealt with by an approved method), test methodology (including equivalent procedures and technical procedures), tests conducted, test data validity, and data analysis and adjustment procedures used;

c) T est results : data to demonstrate co mpliance with the provisions of Annex 16,

Volume II regarding maximum emissions levels for the engine type being certificated ; and

d) R eferences

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## SECTION 2. GUIDANCE MATERIAL

PART I. DEFINITIONS AND SYMBOLS

CHAPTER 1

. DEFINI TIONS

Exhaust nozzle . In the exhaust emissions sampling of gas turbine engines where the jet effluxes are not mixed (as in some turbofan engines for example) the nozzle considered is that for the gas generator (core) flow only. Where, however, the jet e fflux is mixed the nozzle considered is the total exit

nozzle.

EQUIVALENT PROCEDURE :

Defining the exhaust nozzle in this manner, where the fan and core nozzles are not coplanar, is problematic. With imperfect knowledge of the fan flow characteristics w hen discharged upstream of the core exit nozzle, the effective nozzle size may be ambiguous. This affects the extreme downstream location of the sampling probe or rake and causes problems in terms of a detailed traverse of the total

exhaust nozzle. In orde r to obtain equivalent, but more accurate gaseous emissions measurements and representative samples, it is considered best practise to arrange the engine configuration in such a way as to separate the fan and core flows, without affecting the engine perfor mance, and sample just the core flow. The above is equally applicable to both gaseous and smoke emission measurements, however for smoke, the dilution and mixing of bypass air also needs to be taken into account and this is covered under Appendix 2

, paragr aph 2.1.

CHAPTER 2. SYMBOLS [Reserved]



### PART II. VENTED FUEL [Reserved]



### PART III. EMISSIONS CERTIFICATION

CHAPTER 1. ADMINISTRATION [Reserved]CAEP/8

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CHAPTER 2. TURBOJET AND TURBOFAN ENGINES INTENDED FOR

PROPULSION ONLY AT SUBSONIC SPEEDS

2.1 General

2.1.1 Applicability

EXPLANATORY INFORMATION :

Part I of Annex 16

, Vol ume II defines a derivative version 1 in terms of emissions certification, but this definition is only referred to in the Annex in the context of granting exemptions and does not specify how the rule should be applied to modifications of already certificated engine types. Many changes to a certificated engine, which are considered to be major from an airworthiness perspective, require an amendment or supplement to the Typ e Certificate (TC). However, this same modification(s) may have no or very little effect on the emissions characteristics of that engine. If Annex 16 is interpreted literally, these small effects would require a full investigation of compliance against th e emissions certification requirements. This may not be necessary in many cases. The following guidelines have been developed in order to help determine whether a modification could be classified as a ―no emission change‖ or if it

would affect the emission s levels to such an extent that the engine type would need to be re

- certificated against Annex 16

, Vol ume II requirements. Of course manufacturers may elect to recertify to the latest requirements at any time.

TECHNICAL PROCEDURE :

1. No emissions chang e

The principle of a ―no emissions change‖ criteria is that an engine would not need to be

re

- certified against the emissions requirements if the manufacturer could demonstrate that the modification(s) would result in a small cumulative change to the cu rrent certified engine emission levels. Cumulative change could be as a result of more than one change at a given time or multiple changes from more than one derivative version of the same engine being developed.

The potential determination of a ―no emissions change‖ is limited to the following

conditions:

i) If all of the characteristic levels prior to any modification are greater than or equal to

95 per cent of the existing ICAO S tandard, the manufacturer must provide new engine

emissions test da ta to demonstrate that the resulting characteristic levels after the cumulative changes since original emission testing will not exceed the existing ICAO exhaust emission

S tandard.

ii) If all of the characteristic levels are less than 95 per cent of th e existing ICAO exhaust

emission S tandards, then new or related emissions test data and good engineering judgment

1 Derivative version. An aircraft gas turbine engine of the same generic family as an origi nally type certificated engine and having features which retain the basic core engine and combustor design of the original model and for which other factors as judged by the certificating authority, have not changed.CAEP/8

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based on substantive analysis may be an acceptable means to demonstrate that the resulting emission levels after the cumulative changes since original emission testing will not exceed the existing ICAO exhaust emission S tandard. 2 Analyses should consider areas such as cycle changes, combustor and fuel nozzle design, or large changes in combustor inlet velocity profile or turbine cooling flows a s discussed in paragraph 5 below.

iii) Any new emissions test data and/or engineering/technical analysis under subparagraphs (i) and (ii) must demonstrate that the cumulative changes in absolute emission levels, as compared to those of the original certif ication, are within: 3

NO X ± 3 g/kN

HC ± 1 g/kN

CO ± 5 g/kN

Smoke ± 2 SN

With respect to the tracking of cumulative changes, an applicant should maintain formal documentation of the technical basis for all approved ―no emissions changes‖ f or an engine

model. The tracking list will be reproduced in each emissions certification dossier

demonstration.

If a modification is classified as a ―no emissions change‖, the characteristic levels for the

derivative version will be considered the same as the parent engine.

2. Changes requiring new emissions levels

A change, or cumulative set of changes to the type design, which is/are not considered a ―no emissions change‖ and thus affects the characteristic levels would require new characteristic le vels to be determined during the certification program. This would normally be done through a new emissions

certification test.

3. Existing emissions certification basis retained

If a modified engine remains on the existing type certificate, it may r etain the existing certification basis of the parent engine 4 if the modification(s):

i ) meets the demonstration criteria of 1(i) or 1(ii);

ii ) results in a decrease of the absolute emissions levels;

iii ) results in an increase of the absolute emissions levels below those prescribed in 1(iii);

iv ) are necessary for improved safety and continued airworthiness (e.g. ADs).

2 Good engineering judgment means judgm ents made consistent with generally accepted scientific and engineering principles and

all available relevant information.

3 Absolute emission level refers to the average of the measured emission levels corrected to reference conditions. This does no t
incl ude application of the Appendix 6 statistical factors used to determine characteristic levels.

4 In terms of emissions certification, the parent engine must have demonstrated emissions compliance and is not considered to b e a derivative of an even earlier Standard itself.CAEP/8

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4. Latest emissions S tandards applied

An engine type should demonstrate compliance with the latest emissions standards when:

i) T he engine requires a new TC;

ii) The engine modification(s) involves significant technical modifications and where, in the judgment of the certificating authority, the engine would not meet the definition of a derivative engine as defined in Annex 16

, Vo l ume II;

iii) The engine modification(s) does not meet the demonstration criteria of 1(i) or 1(ii);

iv) The engine modification(s) results in an increase in any of the absolute emissions levels below those prescribed in 1(iii) but which results in an exc eedance of the existing ICAO

S tandard;

v) The engine modification(s) results in an increase in any of the absolute emissions levels in excess of those prescribed in 1(iii); or

v) There are significant future environmental impacts. 5

5. Engineering an alysis examples

The basic premise in assessing emissions effects of design changes from an engineering analysis perspective is that emissions are mainly affected by cycle changes, combustor and fuel nozzle design, or large changes in combustor inlet vel ocity profile or turbine cooling flows. A number of examples are provided below for illustration.

Cycle change

Annex 16

, Vol ume II only requires the measurement of fuel mass flow by direct measurement to an accuracy of ±2 per cent (Attachment F to Ap pendix 3, d.) and thrust to an accuracy of

±1 per cent at take

- off power and ±5 per cent at the minimum thrust. It may be that no affect on emissions beyond those prescribed in paragraph 1(iii) would be expected unless changes in air fuel ratio (AFR)

resul t in a specific fuel consumption (SFC) change of more than 1 per cent

.

Regarding combustor inlet temperature (T3), the Annex also states that the combustor inlet parameters shall preferably be measured but may be calculated from ambient conditions by

a ppropriate formulas. Following a comparison on T3 detailed traverses versus typical certification test measurements, it was concluded that measurements are within ±6°F (ca. 3.5°C) of theoretical calculations. It may be that no affect on emissions beyond th ose prescribed in paragraph 1(iii) would be expected if the cycle T3 change is within ±6°F.

Combustor and fuel nozzle

Combustor and fuel nozzle changes include some key design characteristics that can significantly affect emissions (e.g. swirl cup fl ow, primary hole flow, front end cooling flow, injector

5 The application of an old engine type to a new aircraft design could mean a life time of 30 years or more and thereby have a more serious impact on the environment than if the engine was produced for spare only.CAEP/8

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atomization). Changes within or outside of production tolerances or part

- to

- part variation may indicate when a change would be important for emissions or else considered to be not measurable. No affe ct on emissions beyond those in prescribed paragraph 1(iii) might be expected if the changes are within current

part

- to

- part variation or prescribed production tolerances.

Boundary conditions

Similar limitations to that for key design characteristic s can be applied to that resulting from changes in boundary conditions. For example, if turbine cooling changes by 2 per cent , one could look at the resulting change in combustor flow distribution, and if the change is of the same order as typical part

- to

- part variation, it may be acceptable to conclude that no affect on emissions beyond those prescribed in paragraph 1(iii) would be expected.

2.1.1.1 The provisions of this chapter shall apply to all turbojet and turbofan engines, as further specified in 2.2 and 2.3, intended for propulsion only at subsonic speeds, except when certificating authorities make exemptions for:

a) specific engine types and derivative versions of such engines for which the type certificate of the first basic type was issued or other equivalent prescribed pro cedure was carried out before

1 January 1965; and

b) a limited number of engines beyond the dates of applicability specified in 2.2 and 2.3 for the manufacture of the individual engine.

2.1.1.2 In such cases, an exem ption document shall be issued by the certificating authority, the identification plates on the engines shall be marked ―EXEMPT,‖ and the grant of exemption shall be noted in the permanent engine record.

TECHNICAL PROCEDURE

1. Introduction

1.1 The c urrent ICAO Annex 16, Volume II contains two different references to applicability

dates:

• ―date of manufacture for the first individual production model‖ which refers to the engine

type certification; and

• ―date of manufacture for the individual engin e‖ which refers to the production date of a specific engine serial number.

1.2 The second reference is used in the application of global engine NO X production cut

- off

S tandards which specify a date after which all in

- production engine models must meet a certain NO X emission S tandard. For example, all engines manufactured after 31 December 1999 must be compliant

with the CAEP/2 NO X S tandard. It should be noted that these requirements are applicable to completeCAEP/8

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new ―engine units‖ released into service as spares or for new aircraft installations, as discussed below, and not engine components required for maintenance aspects, overhaul, parts, etc.

1.3 It is recognized that there may be certain circumstances where it is justified to permit

manufacturers to continue to produce new non

- compliant engine units after a production cut

- off date. These take the form of exemptions against the relevant Annex 16

, Vol ume II provisions.

1.4 In order to promote a harmonized global approach to the granting, impleme nting and monitoring of these exemptions, this section provides guidelines on the process and criteria for issuing exemptions against a NO X production cut

- off S tandard.

2. Exemption p rocess

2.1 Application

2.1.1 The applicant should submit a formal application letter to the competent authority 6 for the manufacture of the exempted engines, signed by an appropriate manager, and copied to all other relevant organizations and involved competent authorities. The letter should include the following informa tion in order for the competent authority to be in a position to review the application:

a) Administration

 Name, address and contact details of the applicant.

b) Scope of application for exemptions

 Engine type (model designation, type cer tificate (TC) number, TC date, emission TC basis, ICAO Engine Emissions Databank Unique Identification (UID) Number).

 Number of engine exemptions requested.

 Duration (end date) of continued production of exempted engines.

 Designate whether the propo sed exempted engines are ―spares‖ or ―new‖ 7 and to whom the engines will be originally delivered.

c) Justification for exemptions

In applying for an exemption, an applicant should, to the extent possible, address the following factors, with quantifica tion, in order to support the merits of the exemption

request:

 t echnical issues, from an environmental and airworthiness perspective, which may have delayed compl iance with a production cut

- off;

 economic impacts on the manufacturer, operator(s) and avi ation industry at large;

6 In most cases this will be the Certificating Authority although it may vary depending on individual Member State processes.

7 In the case that engines are to be ―new‖ (installed on new aircraft), and would thus result in a larger negative environmenta l impact compared to spare e ngines, greater justification could be required to approve this application.CAEP/8

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 environmental effects. This should consider the amount of additional NO X that will be emitted as a result of the exemption. This could include consideration of items

such as:

- the amount that the engine model exceeds the standa rd, taking into account any other engine models in the engine family covered by the same t ype certificate

and their relation to the S tandard;

- the amount of NO X that would be emitted by an alternative engine for the same application;

- impact of changes to reduce NO X on other environmental factors, including community noise and CO 2 emissions;

 i mpact of unforeseen circumstances and hardship due to business circumstances beyond the manufacturer‘s control (e.g. employee strike, supplier disruption or

ca lamitous events) ;

 p rojected future production volumes and plans for producing a compliant version of

the engine model seeking exemption;

 e quity issues in administering the production cut

- off among economically competing parties (e.g. provide rationale for granting this exemption when another manufacturer has a compliant engine and does not need an exemption, taking into account the implications for operator fleet composition, commonality and related issues in the absence of the engine for which exempti ons are sought) ; and

 a ny other relevant factors

.

2.2 Evaluation

2.2.1 The evaluation of an exemption application should be based on the justification provided and the following definitions and criteria:

a ) Use of engines

―Spare engines‖ are defined as complete new engine units which are to be installed on in

service aircraft for maintenance and replacement. It can be presumed that applications associated with engines for this purpose would be granted as long as the emissions were equal

to or better than those engines they are replacing. The application should also include the other items described in paragraphs 2.1.1 (a) and (b), but it would not need to include the items specified in paragraph 2.1.1(c). For spare engines, the evaluation of the exemption application would be conducted for recordkeeping and reporting purposes, but it would not be done for approval of an exemption.

―New engines‖ are defined as complete new engine units which are to be installed on new aircraft. They can only be exempted from a NO X production cut

- off requirement if they already meet the previous standard (e.g. exemption from a CAEP/6 NO X production cut

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only possible if an engine type already meets the CAEP/4 NO X S tandard). Also, in order to gain approval for this ty pe of exemption the applicant must clearly demonstrate that they meet the criteria for an exemption by including items described in paragraphs 2.1.1(a), (b), and (c). The competent authority may require additional information regarding the appropriateness of the potential exemption.

b ) Number of n ew e ngine exemptions

Exemptions should be based on a total number of engines and time period for delivery of these engines, which would be agreed at time the application is approved and based on the

considerations e xplained in 2.1.1.c) above. The number of engines exempted would normally not exceed 75 per engine type certificate and the duration would not exceed four years from the effective date of the production cut

- off. Exemptions would only apply to non

- complia nt engine models on an engine type certificate.

Exemptions for new engines should be processed and approved by the competent authorities for both the manufacture of the exempted engines and the initial operator of the aircraft to which they are to be fitt ed. Given the international nature of aviation, civil aviation authorities of member states should attempt to collaborate and consult on the details of exemptions. In the case where engine type certification is done through a reciprocity agreement between or among member states, the states involved should coordinate on the processing of exemptions and concur before approval is granted.

As part of the review and approval process for exemptions from any production cut

- off requirement associated with the CAE P/6 NO X S tandard, competent authorities may in some cases require a form of NO X emissions offsetting, as appropriate within the context of aviation and considering an applicant's ability to utilize such measures. However, offsetting measures should be app lied only when necessary in view of the number of engines for which exemptions are sought (e.g.

, greater than 30), duration and/or percent exceedance described in an application.

c ) Exceptions

Unlimited exemptions should be granted for spare engines having emissions equivalent to or better than the engines they replace. Engines for use on state aircraft (e.g.

, military, customs and police) are not covered by the Chicago Convention and therefore excluded from these

civil aircraft NO X production cut

- off requi rements.

2.3 Review

The competent authority should review, in a timely manner, the application using the information provided in para graph 2.1 and against the definitions/criteria in para graph 2.2.

The analysis and the conclusions from the review sh ould be communicated to the applicant in a formal response. If the application is approved, the response should clearly state the scope of the exemptions which have been granted. If the application is rejected, then the response should

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3. Registration and c ommunication

3.1 Oversight of the granted exemptions should include the following elements:

• The competent authority should publish details of the exempted engines in an official public register, including engine m odel, max imum number of permitted exemptions and use of engines.

• The applicant should have a quality control process for maintaining oversight of and managing the production of engines which have been granted exemptions against a NO X emissions produc tion cut

- off S tandard.

• Exempted engine plates should be marked with ―EXEMPT [SPARE] or [NEW]‖.

• An exemption should be recorded in the engine release to service document which states conformity with the Type Certificate (e.g.

, EASA Form 1, FAA Form 8130

- 3). Proposed

standard text

- ―[New] or [Spare] Engine exempted from NO X emissions production cut

off requirement‖.

• The applicant should provide, on a regular basis and appropriate to the limitation of the approval, details to the competent authori ty on the actual exempted engines which have been produced (e.g.

, model, serial number, use of engine, aircraft type and serial number on which new engines are installed).

2.1.1.3 The provisions of this chapter shall also apply to engines designed for applications that otherwise would have been fulfilled by turbojet and turbofan engines.

EXPLANATORY INFORMATION

This sentence anticipates the introduction of future engine technologies. The emissions Standards in Chapter 2 would also be applicable to f uture engine types not categorized as a turbo

- jet or turbofan but intended for use in international air transport services. The provision above is not directly applicable to

turbo

- prop engines for example.

2.1.2 Emissions involved [Reserved]

2.1.3 Unit s of measurement

EXPLANATORY INFORMATION

Smoke level is determined indirectly, by means of the loss of reflectance of a filter used to trap smoke particles from a prescribed mass of exhaust per unit area of filter. The result is a dimensionless smoke

n umber ―SN‖ which acts as a surrogate for, or indicator of, plume opacity. These smoke sampling andCAEP/8

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measurement procedures standardized in Annex 16

, Appendix 2 are derived from SAE Aerospace Recommended Practice (ARP) 1179, Aircraft Gas Turbine Exhaust Smok e Measurement.

The smoke measurement S tandard was developed for engines that generated smoke at considerably higher levels than are seen today. This affects the relative accuracy of the method. The measurement is considered (by the SAE E

- 31 committee th at developed the method) to be no more accurate than ±3 SN.

At smoke levels of SN 50

- 60 this represents an accuracy of 6 %

- 5 % . At regulatory standards of 30 and below, relative accuracy becomes 10%

- 20% or more.

2.1.4 Reference conditions

2.1.4.1 A tmospheric conditions

EXPLANATORY INFORMATION

The reference atmospheric conditions to which the gaseous emissions (HC, CO and NO X ) are to be corrected are the reference day conditions, as follows: Temperature = 15 ° C, Humidity = 0.00634 kg

H 2 O/kg of dry air, Pressure = 101.325 kPa.

2.1.4.2 Thrust settings [Reserved]

2.1.4.3 Reference emissions landing and take

- off (LTO) cycle

EXPLANATORY INFORMATION

The exhaust emissions test is designed to measure hydrocarbons, carbon monoxide, carbon dioxide and oxides of nitrogen concentrations, and to determine mass emissions through calculations during a simulated aircraft landing

- takeoff cycle (LTO). The LTO cycle is based on times in mode data during high activity periods at major airports for four modes of engine operation: taxi/idle, takeoff, climb

- out, and approach. The mass emissions for these modes are combined to yield the reported emissions

certification levels.

2.1.4.4 Fuel specifications

EXPLANATORY INFORMATION

Aircraft gas turbine engines use a variety of fuels. The specific fuel type and composition can and often does have a significant effect on engine emissions. Hence

, it is an important factor when comparing emissions levels from one engine with those from another. It is particularly import ant in evaluating engine emission levels relative to a regulation that was based, in part, on an assumed fuel specification. The ICAO fuel specification defined in Appendix 4 is typical, but tighter, than the general Jet A aviation fuelCAEP/8

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specification. The requirement for emissions certification testing with a fuel that meets a particular specification provides a fixed point of reference for the engine. It provides for some degree of control over the effect of fuel composition on smoke formation and emission . It also helps in the assessment of the effects of changing technology.

2.1.5 Test Conditions [Reserved]

2.2 Smoke

2.2.1 Applicability [Reserved]

2.2.2 Regulatory Smoke Number [Reserved]

2.3 Gaseous Emissions

2.3.1 Applicability [Reserved]

2.3.2 R egulatory levels

EXPLANATORY INFORMATION

The date when a S tandard in paragraph 2.2 and 2.3 becomes applicable within a certification project is

related to the ―.

. . date of manufacture of the first individual production model

. ..‖. As this date is not

al ways clear, certificating authorities have used the date of issue of the engine type certificate (TC) as a surrogate. The date is transparent as it is recorded on the TC and has therefore proven a useful approach in defining the certification basis for an engine type or model.

The Part 1, Chapter 1 definition of ―Date of manufacture‖ refers to the date of the document issued to an individual production engine which attests compliance with the type certificate.

2.4 Information Required

2.4.1 General inf

ormation [Reserved]

2.4.2 Test information [Reserved]

2.4.3 Derived information

EXPLANATORY INFORMATION

The ―maximum Smoke Number‖ is formally defined as the greatest value of SN measured at any of the four thrust levels defined in 2.1.4.2. However, i f a higher S moke N umber is measured at any other test

condition between 7 per cent and 100 per cent of rated thrust during emissions certification tests, it is recommended that the higher value be reported as the ―Maximum Smoke Number‖.CAEP/8

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CHAPTER 3. TURB O JET AND TURBOFAN ENGINES INTENDED FOR

PROPULSION AT SUPERSONIC SPEEDS

EXPLANATORY INFORMATION

During the CAEP/7 work programme, Working Group 3 reviewed the historic background on the development of the emissions S tandards for turbojet and turbofan eng ines intended for propulsion at supersonic speeds and discussed general technology aspects of supersonic engines in comparison to those for subsonic applications. The output of this work was reported in CAEP/7

- WP/10 in February 2007.

While further work, t aking into account aircraft and engine development, was considered to be necessary to give clear recommendations on future changes to Chapter 3, the following preliminary observations and conclusions were agreed:

a) The current supersonic Standard seems t o be outdated.

b) The Standard should not be applied for new engine projects.

c) Part III, Chapter 3 of ICAO Annex 16, Volume II would need to be revised.

d) The timescale for updating should take into account the technological development of any new

SS T engine project and be in line with the work to be undertaken on development of revised

noise S tandards.

e) Any alleviation compared to the current subsonic Standard would require detailed technical investigation.

f) In order for these conclusions to be come recommendations work needs to be completed on whether the current subsonic LTO regulatory approach can be applied to supersonic.

g) Effects from cruise emissions from a potential fleet of supersonic business jets require more scientific understanding

.

WG3 continues to monitor developments within the aviation industry and scientific community on this issue. WG3 has also agreed not to update Chapter 3 until a new SST engine project reaches a sufficiently

mature level such that it can inform discussions on potential future revisions.

APPENDIX 2

. SMOKE EMISSION EVALUATION

EXPLANATORY INFORMATION

The procedure for evaluating smoke emissions is an indirect measure of smoke plume visibility which is obtained by using a filter to trap smoke particles c ontained in a predetermined mass of exhaust gas andCAEP/8

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- 22 Appendix B to the Report on Agenda Item 2

measuring the loss of reflectance, i.e., degree of staining, of this filter relative to the absolute reflectance of the filter when clean or free of stain. The uncertainty of the smoke emission evaluation is estimated to be within ±3 SN (smoke numbers).

1. INTRODUCTION AND DEFINITIONS [Reserved]

2. MEASUREMENT OF SMOKE EMISSIONS

2.1 Sampling probe for smoke emissions

a) The probe material with which the exhaust emission sample is in contact shall be stainless steel or any other non

- reactive material.

b) If a probe with multiple sampling orifices is used, all sampling orifices shall be of equal

diameter. ...

EQUIVALENT PROCEDURES

Stainless steel is the preferred probe material but other non

- reacting materials may be more suitable under specific circumstances, e.g. engine exhaust temperatures which exceed the physical specification limits of stainless steel. Inconel 625 and Nimonic 75 alloys have previously been accepted as a non

- reactive probe

materi al in the context of the regulated species. Other materials may be suitable but need to be approved by the certificating authority.

b) ... The probe design shall be such that at least 80 per cent of the pressure drop through the probe assembly is taken at the orifices.

EXPLANATORY INFORMATION

Smoke particles are submicron in size which, for sampling from gas turbine engines, precludes the need for isokinetic sampling. Never

- the

- less good practice would suggest sampling as close to isokinetic as possible . Taking an 80 per cent pressure drop at the probe orifices is a reasonable compromise. Further information on probe design is provided within the section on Appendix 3, paragraph 5.1.1.CAEP/8

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c) The number of locations sampled shall not be less than 12. [Res erved]

d) The sampling plane shall be as close to the engine exhaust nozzle exit plane as permitted by considerations of engine performance but in any case shall be within 0.5 nozzle diameters of the exit plane.

EXPLANATORY INFORMATION

The definition o f the engine exhaust nozzle is contained in Part 1, Chapter 1, Definitions.

EQUIVALENT PROCEDURE (for mixed flow engine configurations)

For accurate gaseous emissions measurements and representative samples, it is considered best practise to arrange the engine configuration in such a way as to separate the fan and core flows, without affecting the engine performance, and to sample just the core flow. This is equally applicable to smoke emission measurements, however for mixed flow engine designs, the dilu tion and mixing of bypass air also needs to be taken into account with respect to the exhaust nozzle location. This means that the measured core SN would need to be corrected analytically for dilution and mixing in order to compare against the original vis ibility criteria.

Currently

, Annex 16

, Vol ume II does not contain any method or procedure for these corrections which has led to inconsistent application of the requirements. Where no specific en gine data is available,

Version 3 of the First Order Approx imation (FOA) for estimating Particulate Matter emissions, which

contains correlations between SN and non

- volatile PM, is provided as a generic dilution correction in the technical procedure below. If it can be shown that an improved correlation is availab le for a given engine type, or the FOA is developed further, then the improved correlation shall be used with the approval of the certificating authority. No generic mixing correction procedure has yet been identified, and as such, certificating authoritie s need to address this issue on a project by project basis. Ideally the measured core SN would already meet the SN limit. Where this is not the case, further evidence may be required to inform a technically based engineering judgement as to whether the plu me could still considered to be invisible. This could include a detailed traverse at the mixed exhaust nozzle plane in order to perform a contour analysis an d determine the level of mixing.

TECHNICAL PROCEDURE

The following procedure is provided as guida nce material on how to correct core Smoke Numbers for dilution at a mixed flow engine exhaust nozzle:CAEP/8

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Step 1: Convert measured core smoke number to equivalent carbon mass concentration

Figure 1: SN plotted against carbon con centration

Based on various research studies, the following FOA carbon correlation equation has been established:

CI = 0.0694(SN) 1.23357 for SN < 30

Example: From an engine with a maximum measured core Smoke Number of 20, the FOA reference curve provi des an equivalent carbon mass concentration of 2.8 mg/m3 at the core exit plane.

Step 2: Adjust carbon mass concentration for mixed stream equivalent

The carbon concentration can now be corrected for the amount of bypass air using the following

formula e:

Example : Assuming a bypass ratio of 5, the mixed carbon mass concentration is 2.8/(1+5) = 0.47 mg/m 3
at the mixed nozzle exit plane.

Step 3: Convert mixed stream carbon mass back to a smoke number

Using the FOA reference c urve, the mixed flow carbon mass (calculated in the previous step) is converted to an equivalent smoke number.

Example : The diluted smoke number, accounting for the fan air using the FOA reference curve, is 4.8 at the mixed nozzle exit plane.

0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5

0 5 10 15 20 25 30

SNCarbon Conc. mg/m3 FOA 3 curve for SN < 30CAEP/8

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e) The applicant shall provide evidence to the certificating authority, by means of detailed traverses, that the proposed probe design and position does provide a representative sample for each prescribed thrust setting.

EXPLANATORY INFORMATION

Smoke measureme nts can be performed by means of a single point probe which is traversed through the sampling plane in sufficient detail to provide a representative sample. This measurement can also be made using a multi

- orifice probe which has been demonstrated to provid e a representative sample by comparison with those of the single point traverse. Work sponsored by the SAE E

- 31 C ommittee has shown that the best agreement between a detailed traverse, used to establish the mean value of smoke emissions in the sampling pla ne, and a multi

- point sampling probe is achieved when this probe ‘ s sampling orifices are located on centres of equal area. The most common configuration is that of a cruciform with the individual orifices equally distributed and located on centres of equal area.

2.2 Sampling line for smoke emissions

2.2.2 Note.

— Stainless steel or carbon loaded grounded polytetrafluoroethylene (PTFE) meet these requirements.

EXPLANATORY INFORMATION

If carbon

- loaded grounded polytetrafluoroethylene (PTFE) is used sp ecial care must be taken to allow sufficient cooling of the exhaust sample from the probe to the PTFE line to prevent damaging the PTFE line and possibly compromising the sample.

2.3 Smoke analysis system

a ) sample size measurement [Reserved]

b ) sample flow rate measurement [Reserved]

c ) filter and holder [Reserved]

d ) valves [Reserved]

e ) vacuum pump [Reserved]

f ) temperature control [Reserved]

g) If it is desired to draw a higher sample flow rate through the probe than through the filter holder, an optional flow splitter may be located between the probe and valve A (Figure 2

- 1), to dump excess flow. The dump line shall be as close as possible to probe off

- take and shallCAEP/8

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- 26 Appendix B to the Report on Agenda Item 2

not affect the ability of the sampling system to maintain the required 80 per cent pressure

dro p across the probe assembly. The dump flow may also be sent to the CO 2 analyser or complete emissions analysis system.

EXPLANATORY INFORMATION

Achieving an 8 0 per cent pressure drop across the probe assembly can result in an unacceptably high sample flo w rate through the filter holder due to the pressure drop taken across the filter. In these instances, a flow splitter may be required.

h) If a flow splitter is used, a test shall be conducted to demonstrate that the flow splitter does not change the smo ke level passing to the filter holder. This may be accomplished by reversing the outlet lines from the flow splitter and showing that, within the accuracy of the method, the smoke level does not change.

EXPLANATORY INFORMATION

Smoke from gas turbine eng ines, although consisting of sub

- micron particles, can be particularly sensitive to flow splitter design or other flow elements in the sampling stream due to inertial separation at very high

flow velocities. This test addresses these concerns and ensures that the splitter design does not adversely impact the smoke emissions evaluation.

i) leak performance [Reserved]

j) reflectometer

EQUIVALENT PROCEDURE

ARP 1179 Rev. C requires the use of a green tristimulus filter to adjust for the effect of vari ous light sources from different reflectometer manufacturers. While this is not a requirement in Annex 16

, Vol ume II, it is considered best practice to follow this approach.

2.4 Fuel specifications [Reserved]

2.5 Smoke measurement procedures

2.5.1 En gine operation [Reserved]

2.5.2 Leakage and cleanliness checksCAEP/8

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EXPLANATORY INFORMATION

Leakage checks are to ensure clean air does not leak into the system thereby diluting the sample and lowering the smoke number. Cleanliness checks ensure that the sampling system is acceptably clean and the collecting filter will not be contaminated. If the probe cannot be removed from the sampling stream during engine start

- up, the probe and lines should be back pressured with a suitably clean gas, such as dry

nitr ogen, to minimize contamination problems.

2.5.3 Smoke measurement

EXPLANATORY INFORMATION

It is common practice, while sampling for smoke, to also measure levels of CO 2 as an operational check of the sampling system. The engine fuel

- air ratio is calcu lated from the measured CO 2 and compared to

the fuel

- air ratio obtained from engine performance data. These should be in agreement within ±10 per

cent at engine power above idle and within ±15 per cent at idle.

Paragraphs a) through d) provides for adjust ing and setting the sample flow rate through the filter holder. To duplicate the pressure drop through the filter holder during actual sampling conditions a clean filter is clamped into the holder. This filter should be removed and discarded before clampi ng a clean filter into the holder as described in d).

3. CALCULATION OF SMOKE NUMBER FROM MEASURED DATA

EXPLANATORY INFORMATION

The absolute reflectance of each clean filter should be determined as well as that of the stained filter. Work performed by Dieck, et al, ―Aircraft Gas Turbine Smoke Measurement Uncertainty Using the SAE/EPA Method‖, Journal of Aircraft, Vol. 15, No. 4, April 1978, concluded that ―The major

instrument

- related source of error in SAE/EPA smoke measurement is clean

- filter reflect ance precision. It is a direct result of the variability in filter reflectance about the average value used‖.

The backing material should be flat and provide equal pressure across the surface of the filter.

4. REPORTING OF DATA TO THE CERTIFICATING AU THORITY [Reserved]CAEP/8

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APPENDIX 3

. INSTRUMENTATION AND MEASUREMENT TECHNIQUES FOR GASEOUS EMISSIONS

1. INTRODUCTION

EXPLANATORY INFORMATION

The sampling and analysis procedures prescribed in ICAO Annex 16

, Volume II, Second Edition, 1993

were adopted from SAE Aerospace Recommended Practice ARP 1256, "Procedure for the Continuous Sampling and Measurement of Gaseous Emissions from Aircraft Turbine Engines". The calculation procedures were derived from ARP 1533  ̳Procedure for the Analysis and Eval uation of Gaseous Emissions from Aircraft Engines‖. ARP 1256 and ARP 1533 were developed and are maintained by SAE

committee E

- 31, Aircraft Exhaust Emission Measurement.

2. DEFINITIONS [Reserved]

3. DATA REQUIRED

3.1 Gaseous Emissions

a) Hydrocarbo ns (HC): a combined estimate of all hydrocarbon compounds present in the exhaust gas.

EXPLANATORY INFORMATION

Gas turbine engine exhaust gases typically contain a variety of hydrocarbon compounds. The specific compounds present and their relative concen trations are usually unknown. Flame Ionization Detectors, used to measure hydrocarbons, do not respond equally to all hydrocarbon compounds. Although this differential hydrocarbon response is to be held within specific bounds, the resulting measurement is an estimate of the hydrocarbon compounds present in the exhaust gas.

3.2 Other information [Reserved]

4. GENERAL ARRANGEMENT OF THE SYSTEM

EXPLANATORY INFORMATION

Water is a major product of combustion. Its removal upstream of the measuring instrumen ts is attractive. Removal would minimize possible interference effects where the instrument responds to the water present as well as to the gas or vapour being measured. It would also prevent or minimize water condensing in the

instruments which could cau se erratic flow and/or contamination. In the worst case, the instrument would be rendered inoperable until thoroughly cleaned. However, devices which remove water are known toCAEP/8

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- 29

remove hydrocarbons and oxides of nitrogen, and are therefore only permitted for CO and CO 2 measurements. If the sample is dried, an appropriate dry/semi

- dry to wet correction must be made.

For most aircraft gas turbine engines, and most engine running modes, supplemental pumps will be needed to meet the probe system pressure drop re quirement (80 per cent at the probe entrance orifices), the sample line residence time and pressure drop, and the need to remove excess flow from the sampling system. Any pump used for the purpose of sample transfer must be heated. Usually, because of the sample gas physical properties and the need to maintain temperature and flow control within the Flame Ionization Detector used for hydrocarbon analysis, these instruments utilize internal heated, inert sample transfer pumps. The use of an upstream flow spl itter to dump a portion of the sample is also an acceptable procedure to assist in controlling flow to the analytical sampling train.

If loss of hydrocarbons in the sampling system is a concern, the FID can be, when configured with a heated transfer pump, located upstream of the system hot pump as close as physical constraints will allow (e.g. temperature, noise, vibration). The necessity for a dump and/or a hot

- sample pump will depend on the ability to meet the sample transfer time and analysis sub

- system sample flow rate requirements. This in turn depends on the exhaust sample driving pressure and line losses. Therefore, in general, the size and location of the pumps, and the associated flow control devices, are determined from the particular sampling sys tem configuration.

5. DESCRIPTION OF COMPONENT PARTS

5.1 Sampling system

5.1.1 Sampling probe

a) The probe material with which the exhaust emission sample is in contact shall be stainless steel or any other non

- reactive material.

b) If a probe with m

ultiple sample orifices is used, all sampling orifices shall be of equal

diameter.

...

EQUIVALENT PROCEDURES

Stainless steel is the preferred probe material but other non

- reacting materials may be more suitable under specific circumstances, e.g. engine ex haust temperatures which exceed the physical specification limits of stainless steel. Inconel 625 and Nimonic 75 alloys have previously been accepted as a non

- reactive probe material in the context of the regulated species. Other materials may be suitable but need to be approved by the certificating authority.

EXPLANATORY INFORMATION

A probe design with multiple orifices (mixing probe) could include either several sampling orifices leading into a single plenum, or several sampling orifices leading into in dividual sample lines which are mixed external to the probe, as shown in Figure App.3

- 1. The sampling orifices should be equal in size and located on centres of equal area for all mixing probes. If a multi

- armed probe is used, then there should be an equal number of orifices on each arm. Considerations for probe design leading to theseCAEP/8

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- 30 Appendix B to the Report on Agenda Item 2

criteria can be found in ―Gas/Turbine Emission Probe Factors‖, SAE Aerospace Information Report AIR4068A, 1996.The most common configuration is that of cruciform with individ ual orifices located on centres of equal area.

b)

... The probe design shall be such that at least 80 per cent of the pressure drop through the probe assembly is taken at the orifices.

EXPLANATORY INFORMATION

The pressure drop is needed to isokinetically sample flows at the different orifices. The orifice is supposed to be the minimum area right at the probe entrance. To achieve the pressure drop criterion, there must be a rapid expansion into the sampling tube.

The pressure drop refers to the dynamic h ead , not the total pressure, and is needed to ensure that each orifice takes a flow rate that is proportional to the dynamic head present at the sampling orifice. Thus, when the samples taken by the individual sampling orifices are mixed together within th e probe, the total sample is representative of the mass flux of emissions through the engine exhaust sampling plane.

Figure App.3

- 1. Sampling probe designs

c) The number of locations sampled shall not be less than 12.CAEP/8

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EXPLANATORY INFORMATION

While 12 orifices is the minimum number for a sampling rake in Annex 16, Volume II, a more appropriate number would be 20 when validated by means of a detailed traverse.

d) The sampling plane shall be as close to the engine exhaust nozzle exit plane as permitted by considerations of engine performance but in any case shall be within 0.5 nozzle diameter of the exit plane.

EXPLANATORY INFORMATION

Further guidance on the issue of ―Exhaust Nozzle‖ is available un der the Definitions in Part 1, Chapter 1.

e) The applicant shall provide evidence to the certificating authority, by means of detailed traverses, that the proposed probe design and position does provide a representative sample for each prescribed thrust setting.

EXPLANATORY INFORMATION

Detailed traverse measurements, although expensive, could be performed with a single hole probe which measures stabilized concentrations at various positions. These individual measurements will then be used

to derive ave rage values and demonstrate representative sampling. The carbon balance check is also derived in the same way. The ―80 per cent pressure drop‖ condition which has been introduced in the past to guarantee the sample is representative, is no more justified f or the purpose of a single hole probe.

TECHNICAL PROCEDURE

There is no standard definition of a ―representative sample‖ for emissions from aircraft gas turbine engines, nor is there a specification for ―detailed traverse‖. ―Representative‖ and ―detailed‖ are, in this instance, matters of opinion to be negotiated between the manufacturer and the certificating authority. The issue is to do with how much the measured averaged sample can deviate from the true sample mean before it is no longer considered to be representative. The most commonly used definition, arrived at from decades of testing and collaborative analytical exercises by user groups, is 10 per cent for engine modes above idle (i.e., approach, decent, climb and take

- off), and ±15 per cent for id le, as per the carbon balance check in section 6.4 of Appendix 3. There is a significant difference however. For the carbon balance check a comparison is made between sets of independently related measured values. With knowledge about the combustion proces s and the hydrogen to carbon ratio of the fuel used, an estimate can be made from the measured carbon containing species, most of which is CO 2 , of the engine average fuel to air ratio. The actual engine fuel to air ratio can be independently arrived at fro m measured fuel and airflow. These two values can be compared to provide an estimate of how well the exhaust stream was sampled for carbon containing compounds. However, as CO 2 far outweighs the influence of any other carbon bearing species in the calcula tion of fuel to air ratios, the spatial variability of CO 2 will determine how many sampling points are required and how these sampling points should be distributed. CO 2 has been found to consistently exhibit the least variability of all the species of inte rest, which include CO

, HC,CAEP/8

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NO X and smoke. This suggests that it would be possible to meet the 10 and 15 per cent criteria for carbon balance without having obtained a representative sample, using the same 10 and 15 per cent criteria, of the other species. In other words, obtaining a carbon balance, while a necessary pre

- condition for a representative sample, could not be considered to be a sufficient demonstration of representative sampling

on its own.

Historically engine manufacturers, or testing agenci es, have addressed this problem in different ways. Recognizing that gas turbine engines are predominately axi

- symmetric, one acceptable method (for fixed rake designs) has been to sample the exhaust plume, point by point, with a sufficient number of points to be able to estimate, by statistical means, the true engine average species concentration for each of the species of interest. Engine exhaust species seem almost normally (Gaussian) distributed, thus making simple statistical tools acceptable. Using th ese sampling points, and the measured concentration values for each of the species of interest, contour plots of constant concentration (isopleths) have been analytically generated at each power setting tested. There are a number of computer programs avail able for workstations or desktop computers to do this. A probe or rake design is then overlaid on the contour plots in order to estimate the average probe/rake values and compare to the estimated true average arrived

at from the detailed traverse. If the c omparisons match the carbon balance criteria, within 10 per cent for engine powers above idle and ±15 per cent at idle, the probe/rake can be considered to provide representative sampling. This process may have to be repeated several times before an accept able design

is found.

EQUIVALENT PROCEDURE

When applying this analytical technique, for core flow only, multi

- orifice rake designs which have proven most robust seem to have four sampling arms spaced 90 degrees apart with sampling orifices located on

cen tres of equal area. The sampling orifices are equally distributed across the sampling arms and the contour analysis will determine the minimum number of sampling ports necessary to yield a representative sample.

A detailed traverse was not required for r otating rake designs as they provide, in normal use, as many or more sampling points than the typical single point traverse thus ensuring a representative sample. However, in order to demonstrate that a fixed rake design is orientated in the right position to collect a representative sample, traverse measurements were necessary. The detail (single point, number of rake orientations, number of different power settings) of traverse measurements may depend on the number of sampling orifices on the rake and exi sting experience of similar engines or derivatives. These rake design requirements were recognized as being complemented by the system check performed in the carbon balance criteria. Where a sample has low EIs and relatively large ―per cent‖ variations bet ween the detailed traverse and the fixed rake measurements, it could be accepted as representative without having

demonstrated NO X , CO and HC to be within 10 per cent (15 per cent for idle) as long as there is a sufficient large number of orifices and an A FR match within 10 per cent (15 per cent at idle).

All data used in arriving at a probe/rake design should be made available to the certificating authority.

5.1.2 Sampling lines [Reserved]

5.2 HC Analyser [Reserved]CAEP/8

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5.3 CO and CO 2 analysers [Reserved]

5.4 NO X analysers [Reserved]

6. GENERAL TEST PROCEDURES

6.1 Engine operation [Reserved]

6.2 Major instrument calibration [Reserved]

6.3 Operation [Reserved]

6.4 Carbon balance check [Reserved]

7. CALCULATIONS

TECHNICAL PROCEDURE

This technical p rocedure provides guidance on the processing of measured data from an emissions certification test in the form of a simplified worked example.

Definitions:

Reference engine

– For this example, the emissions certification values are calculated based on

co mbustor inlet conditions (T3, P3, and fuel flow) from a validated engine performance model.

Test engine(s)

– Recommended practice is to use an engine which conforms to the production build standard. If differences exist, these differences must be docum ented for approval by the certificating authorities. If any of these non

- conformances are predicted to impact engine performance, gaseous emissions or smoke levels, then an explanation and quantification of the impacts will be provided to the certificatin g authorities for approval. Generally manufacturers will keep deviations from the production standard to a minimum. Measured emissions levels will be corrected to reference engine (production build standard) and standard day conditions.

Detailed tra verse

– For a new engine type, the next step prior to the actual emission certification test is to conduct a detailed traverse of the engine exhaust to show that a representative sample is being obtained (further guidance in the ETM on detailed traverse se e ETM Appendix 3, 5.1.1).

Emissions tests

– Emissions are typically measured at more than the four required thrust levels (typically 8

- 16 conditions) between ground idle and maximum rated thrust.

Instrument calibration curves for the different analyzers may need to be established in order to translate instrument readings to calibrated concentration values. These gas concentrations will be recorded and emission indices will be calculated from that using the equations in 7.1.2 of the Annex 16 Vol. II. The following simple example shows how to derive EI(CO). Assuming the measured values all on a wet basis:

n/m = H/C = 2; CO = 500 ppm(v) wet = 0,0005;CAEP/8

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2 B

- 34 Appendix B to the Report on Agenda Item 2

HC = 800 ppm(v) wet = 0,0008;

CO 2 = 2,25% = 0,0225;

NO 2 = 20 ppm(v) wet = 0,00002;

h amb = 0,0025 vol water

/v ol dryair CxHy = CH 4  x=1, y=4

The equation in 7.1.2 for EI(CO) would then read:

EI(CO) = (CO/(CO + CO 2 + HC)) * (10 3 * 28,011g / ( 12,011g + n/m* 1,008g) * (1 + (0,0003 * (P 0 /m)))

Where:

(P 0 /m) = (2*Z

- n/m) = 2*Z

– 2 Z = {2

– CO

– (2/1

– 4/2*1) * H C + NO2}/ {CO + CO 2 + HC}

= 2

– 0,0005

– 0 * HC + 0,00002 = 1,99952 (P 0 /m) = 1,99904

Hence, from the equation above:

EI(CO) = (0,0005/0,0225+0,0005+0,0008) * (28011/(12,011 + 2,016)) * (1 + (0,0003*1,99904))

= 0,021008 * 1996,934483 * 1,000056 = 41,98 g/kg fuel

EI(HC) and EI(NO X ) are calculated in a similar manner using the other two equations in 7.1.2. For EI(NO X ) the NO 2 /NO converter efficiency must also be taken into account. EIs are calculated for each measurement point (thrust condition) a nd engine run.

Attachment E of Appendix 3 contains a comprehensive and precise numerical method which is often used by engine manufacturers software programs. Further information is contained in SAE ARP 1533 Procedure for the Analysis and Evaluation of G aseous Emissions from Aircraft Engines which contains two fully worked examples of the Matrix method solving the combustion chemical equation.

To correct these EIs from measured to reference engine and ambient conditions, a curve fitting technique

is rec ommended. One acceptable alternative method of plotting measured test data is to plot the following:

EI(CO) * P3 v. T3

EI(HC) * P3 v. T3

EI(NO

x ) * P3 ^

- 0.5 * exp (19 [ h

mass – 0.006 34 ] ) v. T3

A best fit of each of the data curves can then be obtain ed, typically using a polynomial function. In some cases, two curve fit equations are needed, one for low power data and one for high power data. When more than one engine test has been conducted on an engine, data may be plotted for each test run or a

s ingle correlation may be used for the multiple runs. However, if multiple engines are tested, a separate set of plots should be made for each test engine.

The procedure for calculating the corrected EI(CO) at values of Fn corresponding to the four LTO

op erating modes includes the following steps (as shown in Figure A3.1) [Reserved] :CAEP/8

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1

. Use validated engine performance model to determine T3ref, P3ref and reference fuel flow

2

. Starting with T3ref, determine EI(CO) * P3 from the EI(CO) * P3 v. T3 curve

3

. Divide b y the corresponding P3ref to get: Corrected EI(CO) = EI(CO) * P3 / P3ref

Calculation of corrected EI(HC) follows exactly the same process as EI (CO), as does the calculation of corrected EI(NOx) except step 3 involves multiplying by P3ref ^ 0.5 rather tha n dividing by P3ref.

Once the Corrected EI(CO), EI(HC) and EI(NOx) have been calculated for each operating mode, Dp is calculated using the standard LTO times in mode and corresponding values of reference fuel flow from the validated engine performance mo del.

Figure A3.1

– Gaseous Emissions Calculation Procedure

7.1 Gaseous emissions [Reserved]

7.1.1 General [Reserved]

7.1.2 Basic Parameters [Reserved]CAEP/8

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7.1.3 Correction of emissions indices to reference conditions [Reserved]

7.2 Control parameter functions [Reserved]

7.3 Exceptions to the proposed procedures [Reserved]

ATTACHMENT A TO APPENDIX 3. SPECIFICATION FOR HC ANALYSER

1. GENERAL

Precautions : The performance specifications indicated are generally for analyser full scale. Errors at part scale may be a significantly greater percentage of reading. The relevance and importance of such increases shall be considered when preparing to make measurements. If better performance is necessary, then appropriate precautions shall be taken.

EXPLANATORY INFORMATION

The performance specifications for these analyzers, given in terms of full scale response, can have a significant and adverse impact on part scale measurements. In extreme instances, concentrations of HC at high power, such as take

- off, can differ from concentrations at idle by orders of magnitude. In general it is always good practice to use a multi

- range instrument and to adjust ranges such as to keep the measurement in the upper 30 per cent of the instrument response range. Calib rations should be performed on each range used as required.

The instrument to be used shall be such as to maintain the temperature of the detector and sample

handling components at a set point temperature within the range 155°C to 165°C to a stability of ±2°C.

EXPLANATORY INFORMATION

ICAO Annex 16, Volume II previously (Amendment 6 and before) had a set point temperature within the range of 155 o C to 165 o C to a stability of +/

- 2°C . This was adopted from SAE ARP1256, ―Procedure for the Continuous Sampli ng and Measurement of Gaseous Emissions From Aircraft Turbine Engines

- 1971. ARP1256 specified this range to meet the need for minimising the condensation of hydrocarbons in the instrument and in recognition of the operating characteristics of then commer cially available total hydrocarbon analysers (THAs). Since then the ARP has been revised, and now requires a single temperature set point of not less than 160 o C but with no temperature stability requirement. Commercially

available THAs have evolved and the more common detector housing temperatures approach 200 o C. This increase in temperature does not effect the emissions certification measurements but does place an unnecessary constraint on the test procedure.

a ) Total range : 0 to 5 000 ppmC in appropriate r anges.CAEP/8

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EXPLANATORY INFORMATION

A total range of 0 to 5,000 ppmC, while appropriate for the engines in use when Annex 16, Volume II was published in 1981, is broader than needed for today's engines where concentrations are much lower. Appropriate instrum ents should be used to ensure best practice measurements in the upper 30 per cent of the range. Thus an instrument with a range upper limit of 5000ppmC may not be necessary and may, in fact, negatively affect the ability to ensure suitable range span due t o instrument design limitations.

b) Resolution : better than 0.5 per cent of full scale of range used or 0.5 ppmC, whichever is greater. [Reserved]

c) Repeatability : better than ±1 per cent of full scale of range used. or ±0.5 ppmC, whichever is

greater. [Reserved]

d) Stability : better than ±2 per cent of full scale of range used or ±l.0 ppmC, whichever is greater, in a period of 1 hour.

EXPLANATORY INFORMATION

Stability, taken to be span stability and sometimes referred to as repeatability or reprodu cibility, is the maximum variation in instrument output over a specified time period and within specified environmental conditions when identical concentration samples, near FSD, are passed through the instrument and after

zero corrections have been made. Stability is the sum of time dependent drift, i.e. the change in output under invariant laboratory conditions, and changes in output due to other factors such as environmental temperature and/or variations in FID enclosure temperature. Stability is highly dependent on how, and under what environmental conditions the analyzer is used. As such it is out of their control and they choose to specify a value for time dependent drift along with a range of environmental temperatures, i.e., basically under laborator y conditions. Due to improvement of instruments using solid state electronics the drift specifications from modern THC Analysers quote better drift performance (<1 per cent FS over eight hours in laboratory conditions) than the stability requirements of th e standard. Errors associated with this factor are small to negligible. As measurements are not taken under laboratory condition and as changes in environmental conditions are the norm rather than the exception operational procedures, as

described in 6.3.2 d) of Appendix 3 are required.CAEP/8

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e) Zero drift : less than ±1 per cent of full scale of range used or ±0.5 ppmC, whichever is greater, in a period of 1 hour. [Reserved]

f) Noise : 0.5 Hz and greater, less than ±1 per cent of full scale of range used or ±0. 5 ppmC, whichever is greater, in a period of 1 hour.

EXPLANATORY INFORMATION

The FID requires fuel and oxidant gases for operation. The fuel gas is typically either a mixture of hydrogen/nitrogen, or hydrogen/helium. If the noise specification cannot be met, and a hydrogen/nitrogen mixture is being used as the fuel gas, it can be helpful to change to a hydrogen/helium mixture.

g) Response time : shall not exceed 10 seconds from inlet of the sample to the analysis system, to the achievement of 90 per cen t of the final reading. [Reserved]

h) Linearity : response with propane in air shall be linear for each range within ±2 per cent of full scale, otherwise calibration corrections shall be used

. [Reserved]

2. SYNERGISTIC EFFECTS

Oxygen response : measure the response with two blends of propane, at approximately 500 ppmC concentration known to a relative accuracy of ±1 per cent, as follows:

1 ) propane in 10 ±1 per cent O 2 , balance N 2

2 ) propane in 21 ±1 per cent O 2 , balance N 2

If R 1 and R 2 are the respective norm alized responses then ( R 1 - R 2 ) shall be less than 3 per cent of R 1

.

EXPLANATORY INFORMATION

The typical range of O 2 concentrations in the core exhaust gas is 18 per cent at idle to 15 per cent at
take

- off. The specification for a response of <3 per cen t between samples of 10 per cent and 21 per cent is conservative and effectively limits the differential response to <1 per cent over the range of interest. If

needed the O 2 response can be minimized by adjusting the FID burner fuel/air ratio.CAEP/8

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Different ial hydrocarbon response: measure the response with four blends of different hydrocarbons in air, at concentrations of approximately 500 ppmC, known to a relative accuracy of ±1 per cent, as

follows:

a ) propane in zero air

b ) propylene in zero air

c ) toluene in zero air

d ) n

- hexane in zero air.

If R

a , R b , R

c and R d are, respectively, the normalized responses (with respect to propane), then ( R

a – R b ), ( R

a – R

c ) and ( R

a – R d ) shall each be less than 5 per cent of R

a .

EXPLANATORY INFORMATION

While the FID response is assumed to respond in a manner proportional to carbon number, it does vary somewhat with the particular hydrocarbon or class of hydrocarbons being measured. For example, three molecules of methane (CH4) will not necessarily result in the same instrumen t response as one molecule of propane (C3H8). Due to this differential response, it is useful to think of the FID as responding to an ―effective‖ carbon number. It is important that the instrument responses are acceptable for all of the hydrocarbons in the engine exhaust. The group of hydrocarbons (propylene, toluene, and n

- hexane), with propane as a reference, was chosen to represent, in terms of differential response, the range of hydrocarbons expected in the engine exhaust.

3. OPTIMIZATION OF DETEC TOR RESPONSE AND ALIGNMENT

3.1 The manufacturer‘s instructions for initial setting up procedures and ancillary services and supplies required shall be implemented, and the instrument allowed to stabilize. All setting adjustments shall

involve iterative zero checking, and correction as necessary. Using as sample a mixture of approximately 500 ppmC of propane in air, the response characteristics for variations first in fuel flow and then, near an optimum fuel flow, for variations in dilution air flow to s elect its optimum shall be determined. The oxygen and differential hydrocarbon responses shall then be determined as indicated above.

EXPLANATORY INFORMATION

The FID detector response and alignment can be optimized by adjusting the FID burner fuel and a ir flow while sampling a mixture containing approximately 500 ppmC propane. Care should be taken when changing fuel flow that the instrument zero does not shift. If it does, the instrument zero should be reset. Response curves illustrating this process are shown in Figures A3

- 3 and A3

- 4, and were taken from SAE ARP1256, "Procedure for the Continuous Sampling and Measurement of Gaseous Emissions from Aircraft Turbine Engines".CAEP/8

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Figure A3

- 3 Typical Fuel Flow Response Curve

Figure A3

- 4 Typical Airflow R esponse Curve



### The objective of this procedure is to select operating flow rates which will give near maximum response with least variation for minor fuel flow variations. It may be necessary to repeat this operation in an iterative fashion:

• Adjust the fuel flow to maximize output;

• Adjust zero if necessary;

• Adjust the air flow to maximize output;

• Readjust the fuel flow, if necessary; andCAEP/8

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- 41



### • Repeat until the burner output is optimized.

APPEN DIX 4. SPECIFICATION FOR FUEL

TO BE USED IN AIRCRAFT TUR BINE ENGINE EMISSION TESTING

The fuel used during tests shall meet the specifications of this Appendix 4, unless a deviation and any necessary corrections have been agreed by the certificating authority.

Additives used for the purpose of smoke suppress ion (such as organo

- metallic compounds) shall not be present.

EQUIVALENT PROCEDURE

Appropriate evidence should be provided to the certificating authority to substantiate any deviation from the fuel specification of Appendix 4 as early as possible.

A deviation may be accepted when it can be shown that the locally available fuel does not meet the specification. In such a case, use of the available fuel may be acceptable, subject to the substantiation of corrections to compensate for the effect of the de viation on the measured emissions levels. The measured data should then be corrected to reflect the limiting values of the fuel specification of Appendix 4. Corrections will normally be accepted when the magnitude of the correction to the measured data is small in relation to the margin to the certification limits.

The corrections to the declared emission levels resulting from the deviation in test fuel properties should be based upon engine or rig test data which can be related to the specific combustor type, supported by validated analysis where necessary. The corrections would need to be conservative, particularly when test data is not available for the specific combustor type being certificated. Manufacturers should avoid use of

fuels that have been he avily hydro

- treated, or produced using synthetic processes.

The deviations from the fuel specification, and the associated corrections, require the agreement of the certificating authority.

APPENDIX 5

. INSTRUMENTATION AND MEASUREMENT TECHNIQUES

FOR GASEOUS EMISSIONS FROM AFTERBURNING GAS TURBINE ENGINES [Reserved]

APP ENDIX 6. COMPLIANCE PROCEDURES

FOR GASEOUS EMISSIONS AND SMOKE

[Reserved]

— — — — — — — —CAEP/8

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APPENDIX C

Amendment to Doc 9889

New C hapters on Dispersion Modeling and Ambient Measurements,

and R evised Aircraft and Ro ad Vehicle Emissions Inventory C hapters for the

Airport Air Quality Guidance Manual2 C

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Appendix 1

Airport Air Quality

– Chapter 2 Emissions Inventory

Chapter 2

EMISSIONS INVENTORY

Annex 1

AIRCRAFT EMISSIONS

Table of Contents

A1.1 Introduction
A1.2 Aircraft Engine Emission Certification
A1.3 Aircraft Operational Flight Cycle A1.4 Aircraft Emission Calculation Approaches

A1.5 Airc raft Fleet and Movements
A1.6 Aircraft Main Engine Emission Calculations A1.7 Auxiliary Power Units Emissions

Appendix A Example ICAO Engine Emissions Datasheet
Appendix B Simplified Aircraft Emission Indices
Appendix C Definition of Publicly Availabl e Databases for Use in the Matching Aircraft Type

with Engine Type
Appendix D First Order Approximation v3.0 Method for Estimating PM Emissions from

Aircraft EnginesCAEP/8

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A1.1 Introduction

A1.1.1 Aircraft main engines may, at times, receive t he most amount of attention from those parties concerned with aviation emissions as they can be the dominant airport

- related source. This chapter recommends methodologies for the estimation of aircraft engine emissions. Main engines are those used to prope l the aircraft forward. Other on

- board engines include APU that provide electrical power and pneumatic bleed air when the aircraft is taxiing or parked at the gate and no alternative is available. Fuel venting from aircraft fuel tanks is not allowed and th erefore is not

addressed as an emission source.

A1.1.2 Main engines are generally classified as either gas turbine turbofan (sometimes referred to as turbojet) and turboprop engines fuelled with aviation kerosene (also referred to as jet fuel) and internal combustion piston engines fuelled with aviation gasoline.

A1.1.4 Main Engine Emissions in the Vicinity of Airports

A1.1.5 Emissions from an individual aircraft main engine combination are primarily a function of three parameters: Time

- in

- mode (TIM), main engine emission indices (EI), and main engine fuel flows. Aggregate emissions from a fleet serving an airport also include two additional parameters; fleet size/type and number of operations. In the calculation of aircraft emissions at a given airport, th e desired accuracy of the emissions inventory will dictate the values and methodology (e.g., Simple, Advanced, or Sophisticated approach) used for determining each of these parameters. While this document tries to simplify the inventory analysis into three approaches, it is generally agreed that the user may at times use a hybrid approach, combining elements from the simple, advanced and sophisticated approaches. However, care should be taken not to use a hybrid approach where all aspects are over

- estimate d thereby inadvertently assigning a higher burden to aircraft emissions when assessing airport inventories. Consequently, it is recommended that the analyst fully document the analysis methodology including how the guidance document is used. This is disc ussed further in the ―Emissions Calculation Approaches‖ Section A1.4. The following information provides basic descriptions of each of these parameters:

A1.1.6 Time

- in

- mode (TIM) is the time period, usually measured in minutes, that the aircraft engines ac tually spends at an identified power setting; typically pertaining to one of the LTO operating modes of the operational flight cycle.

A1.1.7 Emission Index (EI) and Fuel Flow: An emission index is defined as the mass of pollutant emitted per unit mass of fuel burned for a specified engine. The ICAO Engine Emissions Databank provides the EI for certified engines in units of grams of pollutant per kilogram of fuel (g/kg) for NOx, CO, and HC, as well as the mode

- specific fuel flow in units of kilogram per se cond (kg/s), for the four power settings of the engine emissions certification scheme. Multiplying the mode

- specific EI by the TIM

- specific fuel flow yields a mode

- specific emission rate in units of grams per LTO. For more accurate inventories, adjustments are necessary to these values to take account of, for instance, different power settings, installation effects, etc.

A1.2 Emissions Certification LTO Cycle

A1.2.1 For emissions certification purposes, ICAO has defined a specific reference LTO cycle below a height of 915 meters (3,000 feet) AGL 1 , in conjunction with its internationally

1 AGL: In an emissions inventory s tudy 3000ft Above Ground Level would be referred to the elevation of chosen reference point used in the study. E.g. Elevation AMSL of the ARP.2 C

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agreed certification test, measurement procedures and limits (see ICAO Annex 16 Volume II for additional information).

A1.2.2 This cycle consists of four modal phases chosen to represent approach, taxi/idle, take

off and climb and is a much simplified version of the operational flight cycle. An example of its simplification is that it assumes that operation at take

- off power abruptly changes to climb power

at the end of the t ake

- off roll and that this is maintained unchanged up to 3,000 feet. Whilst not capturing the detail and variations that occur in actual operations, the emissions certification LTO cycle was designed as a reference cycle for the purpose of technology compa rison and repeatedly has been reaffirmed as adequate and appropriate for this purpose.

Operating phase Time

- in

- mode (minutes) Thrust setting

(percentage of rated thrust) Approach 4.0 30 Taxi and ground idle (in) 7.0 7 Taxi and ground idle (out) 19.0 7

Take

- off 0.7 100

Climb 2.2 85

A1.2.3 This reference emissions LTO cycle is intended to address aircraft operations below the atmospheric mixing height or inversion layer. Whilst the actual mixing height can vary from location to location, on average it extends to a height of approximately 915 meters (3,000 feet), the height used in deriving airborne times

- in

- mode. Pollutants emitted below the mixing height can potentially have an effect on local air quality concentrations, with those emitted closer to t he ground having possibly greater effects on ground level concentrations. 2

A1.2.4 The certification LTO cycle characteristics selected were derived from surveys in the 1970s. They reflected peak traffic operations (i.e. typical adverse conditions), rather than average LTO operations. The justification for using these for aircraft emission standards was largely based on protecting air quality in and around large metropolitan air terminals during high operational or adverse meteorological conditions.

A1.2.5 It was recognized that even for aircraft of the same type there were large variations in actual operating times and power settings between different international airports, and even at a single airport there could be significant variations day

- to

- day or th roughout a single day. However the use of a fixed LTO cycle provided a constant frame of reference from which differences in engine emissions performance could be compared.

A1.2.6 Thus, the reference emissions LTO cycle is of necessity an artificial model that is subject to many discrepancies when compared to real world conditions at different airports. It was

2 ICAO recognizes that different States may have different standards or thresholds for designating whether a pol lutant as emitted has a local effect. In many cases, this is expressed in terms of a maximum altitude up to which a particular pollutant is emitted. Some States may specify a specific altitude for such purposes. Others may direct that modeling

be undertake n to identify the altitude at which pollutants may have local effect in a particular area. This is often referred to as the ―mixing height‖ within the atmospheric ―boundary layer.‖ In basic terms, the ―mixing height‖ is the height of the vertical mixing of the lower troposphere. Also in basic terms, the ―boundary layer‖ is that part of the troposphere that is directly influenced by the presence of the earth's surface. States that specify a mixing height is determined for purposes of local air quality assess ment typically have accepted models for such analyses and/or specify a default height for the mixing height, such as 3,000 feet.CAEP/8

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designed as a reference cycle for the purpose of certifying and demonstrating compliance to the

emissions standards in effect.

A1.2.7 This LTO cycle, developed for certification purposes, may also be adequate for simple emissions inventory calculations. However, in light of its generic assumptions, use of this cycle typically would not reflect actual emissions. If more precise operations data are avai lable, these data should be used instead to achieve a more accurate inventory.

A1.2.8 As stated elsewhere in the guidance, ICAO aircraft engine emissions standards cover emissions of CO, HC, NOx and smoke. They apply only to subsonic and supersonic aircraf t turbojet and turbofan engines of thrust rating greater than or equal to 26.7 kN [Annex 16 Volume

II

– Aircraft Engine Emissions]. ICAO excluded small turbofan and turbojet engines (thrust rating less than 26.7 kN), turboprop, piston and turboshaft engine s, APU and general aviation aircraft engines are omitted from ICAO standards on the grounds of the very large number of models, the uneconomic cost of compliance and small fuel usage compared to commercial jet aircraft.

A1.2.9 Emissions Certification Data

A1.2.10 Emissions certification testing is carried out on uninstalled engines in an instrumented and calibrated static test facility. Engine emissions and performance measurements are made at a large number of power settings (typically greater than ten) co vering the whole range from idle to full power and not just at the prescribed four ICAO LTO modes. The measured data are corrected to reference engine performance conditions and reference atmospheric conditions of ISA at sea level and humidity of 0.00634 k g water/kg of air, using well established procedures (See ICAO Annex 16, Volume II for additional information).

A1.2.11 The ICAO engine emissions certification data for CO, HC, and NOx, together with associated fuel flow rates, are reported at a set of fou r reference power settings defined as ―take

off‖, ―climb‖, ―approach‖, and ―taxi/ground idle‖, respectively and for prescribed times at each of these power settings (i.e., ―times

- in

- mode‖). However, smoke emissions are only required to be reported as a max imum value of smoke density, reported as smoke number (SN) for each engine, irrespective of the power setting (although for some certified engines, mode

- specific smoke numbers have been reported).

A1.2.12 The emissions certification values previously desc ribed are provided in the ICAO Engine Emissions Databank, both as individual engine datasheets and also as a spreadsheet containing the data for all certified engines for which manufacturers have made data available. This databank is publicly available on the worldwide web at www.caa.co.uk/srg/environmental and is periodically updated. An example of an Engine Emissions Datasheet is presented in Appendix A.

A1.3 Operational Flight Cycle Description

A 1.3.1 The departure and arrival phases of an actual operational flight cycle for a commercial aircraft are more complex than the four modal phases (i.e., approach, taxi/idle, takeoff, and climb) used for ICAO certification purposes. Actual cycles employ va rious aircraft engine thrust settings, and the times at those settings are affected by factors such as aircraft type, airport and runway layout characteristics, and local meteorological conditions. However, there are a number of segments that are common to virtually all operational flight cycles. These are depicted in the following diagram (Figure A1

- 1) and described in the subsequent sections:2 C

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Figure A1

- 1 Operational Flight Cycle

A1.3.2 Departure

A. Engine start

– It is normal to start the main engines prior to, or during, pushback from the aircraft gate/stand. Where aircraft do not require pushback, the main engines are started immediately prior to taxi.

B. Taxi to runway

– Aircraft typically taxi out on all engines to the runway or holding area prior t o entering the runway; though aircraft may taxi on fewer than all engines under

some circumstances. Taxi

- out is normally carried out at the idle/taxi power setting apart from brief bursts of power to overcome the initial inertia at the start of taxiing; or if necessary, to negotiate sharp turns.

C. Holding on ground

– Where necessary, aircraft may be required to hold in a queue whilst awaiting clearance to enter the runway and taxi to the take

- off position. Main engines are normally set to idle thrust with brief bursts of power to move into position.

D. Take

- off roll to lift

- off

– The aircraft is accelerated along the runway to the predetermined rotation speed and the end of the take

- off run, with the main engines set to

take

- off power. Operators rarely use full power for takeoff; rather, a pre

- determined thrust setting is set at the beginning of the take

- off roll. Operators use either de

- rated

take

- off thrusts or, more often, reduced (e.g., flexible) thrust settings, which are determined by the aircraft actu al take

- off weight, runway length and prevailing meteorological factors. Throttle handling during the take

- off run is sometimes staged in the early part, whereby the throttles are initially set to an intermediate position then a few

seconds later are advan ced to the predetermined take

- off power setting.

E. Initial climb to power cutback

– After leaving the ground, the undercarriage (i.e., wheels) of the aircraft is raised and the aircraft climbs at constant speed with the initial take

- off power setting unti l the aircraft reaches the power cutback height (i.e., between 800 and 1,500 feet agl) where the throttles are retarded.

F. Acceleration, clean

- up and en

- route climb

– After the throttle cutback, the aircraft continues to climb at a thrust setting less tha n that used for take

- off with flap/slat retraction following as the aircraft accelerates and reaches cruising altitude.

A1.3.3 ArrivalCAEP/8

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G. Final approach and flap extension

– The stabilized final approach from the Final Approach Fix (FAF) follows a relativ ely predictable glide slope at low engine thrusts. Thrust settings are increased to counteract the additional drag as flaps and the undercarriage are lowered, whilst speed decreases towards the flare.

H. Flare, touchdown and landing roll

– Throttles are no rmally retarded to idle during the flare and landing roll. This is followed by application of wheel brakes and (where appropriate) reverse thrust to slow down the aircraft on the runway.

I. Taxi from runway to parking stand/gate

– Taxi

- in from the runway i s a similar process to

taxi

- out to the runway described above; however, operators may shut down one or more engines, as appropriate, during the taxi if the opportunity arises.

J. Engine shutdown

– Remaining engines are shut down after the aircraft has stop ped taxiing and power is available for onboard aircraft services.

A1.3.4 APU operation, for aircraft equipped with this equipment, is usually confined to periods when the aircraft is taxiing or stationary at the terminal. The APU is typically shut down jus t after main engine start

- up and after landing, the APU is generally started when the aircraft is approaching the terminal area parking position. If one or more main engines are shut down during the taxi, it may also be necessary to start the APU during th e taxi

- in. A number of airports specify maximum APU running times, principally to limit noise in the terminal area.

A1.3.5 As contained within the following discussion, aircraft activity at an airport is quantified in terms of either LTO cycles or operatio ns. An operation represents either a landing or a takeoff, and two operations can equal one LTO cycle (e.g., taxi out, take

- off, a landing and taxi in).

A1.4 Emissions Calculation Approaches

A1.4.1 There are various approaches, or methodologies, to quanti fy aircraft emissions

– each with a degree of accuracy and an inverse degree of uncertainty.

A.1.4.2 This section covers three general approaches to quantifying aircraft engine emissions, with each still having several levels of complexity incorporated. Each approach may incorporate various options for certain parameters and contributing factors, depending in the availability of

the data and information.

 Simple Approach is the least complicated approach, requires the minimum amount of data, and provides the highest level of uncertainty often resulting in an over estimate of aircraft emissions. It uses public information and data tables that are very easily available and requires a minimum amount of airport specific information.

This is the most basic appr oach for estimating aircraft engine emissions provided in the guidance. The only airport

- specific data required are the number of aircraft movements (over a certain period such as a year) and the type of each aircraft involved in each movement (Option A) o r some additional basic information on the engine used for each aircraft type (Option B).

This Simplified Approach should only be used as means of conducting an initial assessment of the aircraft engine emissions at an airport. For most pollutant species, the approach is generally conservative, meaning that the outcome will often overestimate the total level of aircraft engine emissions. However, for some emission species and less common aircraft, the resultant emissions may be underestimated. As such, it i s unclear2 C

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Appendix C to the Report on Agenda Item 2

how accurately the Simple Approach accounts for actual aircraft engine emissions at a given airport.

 Advanced Approach reflects an increased level of refinement regarding aircraft types, engine types, EI calculations and TIM. This approach requi res specific airport related information or qualified assumptions which are still publicly available but may be more difficult to obtain. It reflects local conditions in incorporating some sort of performance calculation of the aircraft. These improvements result in a more accurate reflection of main engine emissions over the Simple Approach, yet the total emissions are still

considered conservative.

 Sophisticated Approach best reflects actual aircraft emissions. It is the most comprehensive approach, requ ires the maximum amount of data and provides the highest level of certainty. This Sophisticated Approach goes beyond LTO certification data and TIM and utilizes actual engine/aircraft operational performance data. Use of this approach requires a greater kn owledge of aircraft and engine operations and in certain instances will require the use of proprietary data or data or models that are normally not available in the public domain and in most instances require the users to perform higher levels of analysis.

A1.4.3 The alternate methodologies afford a progressively higher degree of accuracy and an inverse degree of uncertainty. The purpose and need for quantifying aircraft emissions drive the level of accuracy needed in an inventory, which in turn, determine s the appropriate methodology. A secondary factor is data availability. Although an analysis may warrant a high degree of accuracy, it may not be possible for certain elements of the analysis due to lack of available data. ICAO urges that if an emissions i nventory involves policies that will affect aircraft operations at a particular airport, then the calculations should be based on the best data available, and the simple approach should not normally be used. Where further information on the aircraft operat ions at an airport is available, then a more advanced approach is more appropriate.

A1.4.4 It is also important to note that, although at its simplest level it may be possible for individuals to construct an emissions inventory, the advanced and sophistica ted methods likely necessitate some form of collaboration with other aviation resources. For example, the identity of actual aircraft and engine types, realistic and accurate times in mode, and actual engine power settings used in the analysis requires dat a that is often difficult to obtain. In general, the more sophisticated the method, the greater the level of collaboration will be required.

A1.4.5 ICAO stresses the importance for airports and States to use the best data available when assembling an aircr aft engine emissions inventory. The ICAO emission inventory methodologies increase in accuracy moving from the Simple to the Advanced and eventually to the Sophisticated Approach. ICAO recommends selecting an approach, or portions thereof, to reflect the d esired, or required, fidelity of the results. The air quality practitioner can reference these approaches as ICAO Simple Approach, Advanced Approach, or Sophisticated Approach. It should also be noted that the methods can be combined and that just because a Simple Approach is used for one part of an inventory, does not preclude the use of more precise approaches from being employed for the remaining parts of the emissions inventory.

A1.4.6 The following table provides an overview of the calculation approach es. It lists each of the four primary parameters (e.g., fleet mix, movements, TIM and EI) along with other contributing factors. Also included are explanations of how each of these parameters are determined using the three approaches (e.g., Simple, Advance d, and Sophisticated).CAEP/8

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Key

Parameters Simple Approach Advanced Approach Sophisticated Approach

Fleet (aircraft/engine combinations) Identification of aircraft group

types (e.g. all B737 or all A319/320/321) Identification of aircraft and representativ e engine types (e.g.

all A320 with 50% V2525 and

50% CFM56

- 5B5P) Actual aircraft type/subtype and engine

combinations (by tail number and engine UID or similar)

Movements Number of aircraft movements

by aircraft type (according to

look

- up table), as def

ined in

"Fleet" Number of aircraft movements by

aircraft

- engine combinations as

defined in "Fleet" Number of

aircraft movements by

aircraft tail

number

Emissions

Calculation Option A

UNFCC Look

up table (no calculation) Option B

Spreadsheet

calculatio n Performance based calculation,

potentially reflecting additional parameters like forward speed, altitude, ambient conditions (model dependent). Performance

based with actual engine data (P3/T3) and including

ambient

conditions

Thrust Levels Option A

N/A Option B

rated thrust Option A

Average airport

and/or aircraft group specific

reduced thrust

rate Option B

Performance

model

calculated

rated reduced

thrust Actual air carrier

provided thrust

Time in Mode Option B

ICAO

Certification

LTO Option A

Modified times in mode (airport specific average

or actual for one

or several modes) Option B

Performance

model

calculated time

in mode. Movement based

actual values for

all modes

Fuel Flow Option B

ICAO

Certification

Databank

Values Option A

De rived from

ICAO EEDB

with thrust to

fuel flow

conversion

model Option B

Derived from

ICAO EEDB

with performance

model Refined values

using actual performance and operational data

derived from air

carrier

Emission

Indices Option A

UNFCC LTO

Emission Mas s by Aircraft Type Option B

ICAO

Certification

Databank

Values Option A

Derived from

ICAO EEDB

and thrust level through BFFM2 curve fitting

method Option B

Derived from

ICAO EEDB through

BFFM2 curve fitting method Refined values

using actual performanc e and operational data

derived from air

carrier.

Start

- up Not Considered Consider including

- See Consider2 C

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Emissions Sections A1.6.66

– A1.6.75 including

- See

Sections A1.6.66

– A1.6.75

Engine

deterioration Do Not Consider

- See Sections

A1.6.56

– A1 .6.65 Do Not Consider

– See Sections

A1.6.56

– A1.6.65 Do Not Consider

– See Sections

A1.6.56

– A1.6.65

TABLE 1

A1.4.7 When choosing an approach for creating an aircraft emission inventory, a mix of the various approaches and options can be selected. Th e choice is based upon the availability of data and information, as well as the required accuracy of the inventory. The various elements as listed and described in Annex 1.4.6 are to some degree independent of each other, i.e. not all "Option

B" elements n ecessarily have to go together.

A1.4.8 For logical and consistency reasons, the "Fleet" and "Movements" elements for each approach go together. The Simple Approach Option A as well cannot be mixed with other options or approaches; the same holds true for the Sophisticated Approach. The other elements (Simple Approach Option B and Advanced Options A and B) can be mixed.

A1.4.9 As a prelude to the details involved in each approach, ICAO wishes to establish the general concept within each method. In summary, the inventory starts with an individual aircraft/engine combination(s), and generally applies the operational and emission parameters in a

two

- step process, as follows:

Step One: Calculate emissions from a single aircraft/engine combination by summing the emissions from all the operating modes which constitutes an LTO cycle, where emissions from a single mode could be expressed as:

Modal emissions for an aircraft/engine combination = TIM x fuel used (at the appropriate power) x EI (at the appropriate power ) x number of engines

The emissions for the single LTO operational flight cycle are then a summation of the individual parts of the cycle. In more sophisticated methods, EI and fuel flows may not be constant throughout the time in mode.

Step Two: Calculate total emissions by summing over the entire range of aircraft/engine combinations and number of LTO cycles for the period required.

A1.5 Aircraft Fleet and Movements

A1.5.1 Aircraft fleet is a generic description to describe the various aircraft and engin e combinations that serve an airport. In its simplest form, the aircraft fleet can be generally characterised according to descriptors such as, for example, heavy, large, small, turboprop, and piston. For aircraft emissions inventory purposes, however, it is typically necessary to identify fleets more accurately (for example, by aircraft type).

A1.5.2 Aircraft can be generically labelled according to manufacturer and model. For example, ―A320‖ is an Airbus model 320 or a ―B737‖ represents the Boeing 737, th ough it should be noted that a generic aircraft type may contain significant variations in engine technology and widely differing emissions characteristics between different types and their engine fits.

A1.5.3 A more descriptive labelling for an aircraft t ype would also include the series number for each model, such as B747

- 400 for a 400 series Boeing 747 aircraft. This helps to establish theCAEP/8

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size and technology used in the aircraft engine and is necessary for a more accurate emissions inventory.

A1.5.4 Fin ally, the most accurate representation of aircraft is to identify the aircraft model, and series along with the actual engines fitted on the aircraft and modifications that affect its emissions performance (e.g., B777

- 200IGW with GE90

- 85B engines with DAC II combustors). As the aircraft itself does not produce emissions, having detailed information on engines installed on the aircraft fleet is an essential component of an accurate emissions inventory.

A1.5.6 Simple Aircraft Fleet

A1.5.7 For the Simple Appr oach, the two primary elements of the aircraft fleet (e.g., aircraft and engine types) have been simplified in a list of the types of aircraft for which pre

- calculated emission data is provided. For each aircraft, the engine type has been assumed to be the most common type of engine in operation internationally for that aircraft type 3 , and emissions from that engine type are reflected in the associated emission factors. Appendix B contains Table B

- 1 which lists 52 aircraft and provides emission data for eac h of their engine types. 4

A1.5.8 If the fleet servicing an airport includes aircraft that are not contained in Table B

- 1,

then Table B

- 3 should be used to determine an appropriate generic aircraft. (Refer to the column headed ―IATA aircraft in group‖ to l ocate the aircraft type shown in the column headed ―Generic Aircraft Type‖.)

A1.5.9 If an aircraft is not contained in either Table B

- 1 or B

- 3, then it is recommended to use supplementary information such as weight, number of engines, size category, range, etc. to identify a suitable equivalent aircraft that is in Table B

- 1 or B

- 3, recognising that this will introduce additional assumptions that may affect the accuracy of any result. In the case of an airport primarily served by regional jets, business jets and/or turboprops, it is unlikely that the range of aircraft will yield a reliable result. In these cases, a more advanced method is

recommended.

A1.5.10 Simple Aircraft Movements

A1.5.11 For the Simple Approach, it is necessary to know (or to have an es timate of) the number of aircraft movements or operations (e.g., LTO) and type of aircraft at an airport over a specified period (e.g. hour, day, month, or year).

A1.5.12 Most airports levy user charges for provision of facilities and services typically

co llected as a landing fee. In these cases airport operators have accurate records of landing

3 As of 30 July 2004 emissions data for the B747

- 300 is based on proportioned emissions for the two most common engine types.

4 CAEP developed this data at the request of the UNFCCC in connection with UNFCCC guidelines for national greenhouse gas inventories, which are used for global emissions issues rather than local air quality. It therefore includes data for greenhouse gas emi ssions that are not relevant to local air quality. These may be disregarded for purposes of inventories assembled for local air quality assessments (though some locations may wish to inventory

CO 2 emissions for other purposes). The data included in this do cument was current at the time of writing. The UNFCCC will provide updates to this table on an on

- going basis and the most current table should be used whenever possible [ www.ipcc

- nggip.igs.or.jp ]. If using new data from the UNFCCC website, CH4 and NMVOC data will require summing in order to obtain a value for HC. S ince the UNFCCC‘s main focus was on greenhouse gas emissions over the entire course of flight, the data for LTO emissions is based on ICAO certifi cation standards, and therefore will not accurately reflect actual emissions in an operating setting. In most cases, use of the refinements discussed in the Advanced and Sophisticated Approaches will help to achieve a more accurate inventory for the

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movements; including the number of landings and the type of aircraft. Some airports also record

the number of take

- offs, although the landing records usually provid e more reliable data. For this reason, at larger airports, published data on the annual aircraft movements is often available.

A1.5.13 An LTO cycle contains one landing and one take

- off, and so the number of landings and takeoffs at an airport should be eq ual. The total number of either landings or takeoffs may be treated as the number of LTO. Any difference in the number of landings and the number of take

offs will usually indicate an error in the records; if there is no explanation for this discrepancy,

t hen the greater number should be used.

A1.5.14 If no data is available, it will be necessary to conduct a survey of the number of aircraft movements and the types of aircraft over a short

- or medium

- term period (e.g. one to six months), noting that there a re normally seasonal differences in the number of movements at most airports.

A1.5.15 Advanced Aircraft Fleet

A1.5.16 Like the Simple Approach, the first step of the Advanced Approach is to quantify the aircraft operations or LTO by aircraft type and spec ific to the airport. Typically, this information can be obtained directly from airport records, thereby reflecting the most accurate form of this information. However, because no database is entirely accurate and changes due to aircraft engine fits, tempor ary intermixes, and other considerations over time can introduce inaccuracy, it is important to gather as much information as close to the source of the operation as is possible. If access to this information is not possible, then national traffic statisti cs can be accessed if available. Additional sources of data include air navigation service providers such as EUROCONTROL and the U.S. FAA, the internet and the other sources described in the paragraphs below. .

A1.5.17 The Advanced Approach then tries to m atch the various aircraft types operating at the study airport with the engines that are fitted to them. Airports typically have lists with aircraft type/engine combinations obtained from the carriers that service the airport. However, if this

information is unavailable, States have access to several publicly available databases that enable the matching of aircraft types with specific engines. Annex 1 Appendix C describes these important databases that can assist practitioners in identifying the aircraft/en gine combinations that characterize fleet mix at a particular airport.

A1.5.18 Other sources of information include the International Official Airline Guide (IOAG) Database which contains data that identifies the type of aircraft, carrier, and frequency of scheduled flights. In addition, the IOAG lists scheduled passenger flights by participating airlines, which are updated on a monthly basis. IOAG provides the main components in determining the fleet mix at a specific airport such as airport, aircraft type , carrier, and frequency of aircraft arrivals and departures. However, the IOAG does not include unscheduled and charter flights, or general aviation flights including business jets. The IOAG covers the flights of all U.S. scheduled airlines and the majori ty of scheduled worldwide airlines. Specifically, Appendix C provides a description of the useful fields contained in the IOAG database. The most important IOAG airport

- specific parameters are the flight number, aircraft type, carrier, and schedule when

de termining the number of operations at a specific airport.

A1.5.19 BACK‘s World Fleet Registration Database (BACK) contains additional airline fleet information such as all worldwide commercial aircraft currently in use and other various aircraft

parameters (see Appendix C for a list of useful fields). For emissions inventory purposes, theCAEP/8

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Appendix C to the Report on Agenda Item 2 2 C

- 13

most important parameters from the BACK database (or other similar databases) are the aircraft identifiers, tail number, engine model, number of engines, and aircraft type

.
A1.5.20 Bucher & Company‘s JP Airline

- Fleets International Database (JPFleets) is another publicly available database that provides aircraft type/engine combinations for major commercial airlines worldwide (see Appendix C for a list of useful data fields ).

A1.5.21 Airline Service Quality Performance (ASQP) Database is available from the U.S. Department of Transportation‘s (U.S. DOT) Bureau of Transportation Statistics (BTS). This database consists of performance and flight data for approximately 20 of the largest U.S. carriers. Appendix C lists the useful fields in the ASQP database. The practitioner should note the ASQP database provides good coverage for the fleet flying in the U.S. and their associated markets

abroad.

A1.5.22 Depending upon the reasons for assembling an emissions inventory, a different method of assigning engines to aircraft can be used. One approach is to identify the specific engines used for the aircraft operations. This is achieved by collecting aircraft type information,

scheduled f

light numbers, and arrival/departure data for a specific airport (e.g., using IOAG), then finding the specific engine types assigned to the identified aircraft using the available databases described above. If this degree of accuracy is not necessary, then an alternative approach can be used to estimate the engine.

A1.5.23 This alternative is based upon the popularity of engines within the worldwide fleet. If the data available does not allow the identification of specific aircraft

- engine combinations at a particular airport, these might be estimated. One way of doing this is to extrapolate the

information on aircraft

- engine combinations from a larger fleet database, such as a worldwide fleet database. For example, if the reference database shows that X perc ent of the B777 in the worldwide fleet have Y engines, and then it might be assumed for purposes of an airport inventory that X percent of the B777 that operate into that airport have Y engines. States should be aware that a single aircraft type may be fit ted with more than one type or subtype of engine, which in turn can have differing emissions characteristics, in an airline‘s worldwide inventory. For these cases, databases such as BACK, JPFleets, and others can be used to develop distributions of engines based on reported airline and aircraft categories.

A1.5.24 It should be remembered that no database is entirely accurate, and changes due to aircraft engine fits, temporary intermixes, cross

- referencing between databases, and other

considerations over ti me can introduce even greater levels of inaccuracy. It is therefore important to gather as much information as close to the source of the operation as is possible in order to

minimise uncertainties.

A1.5.25 Advanced Aircraft Movements

A1.5.26 The requirem ents for aircraft movements needed for the Advanced Approach is nearly identical to the Simple Approach: it is necessary to know the number of aircraft movements or operations by type of aircraft and engine for the advanced approach. When the emissions for the single LTO are calculated for each aircraft/engine combination using the above inputs and equations, the total emissions are calculated by multiplying the single LTO emissions for each aircraft/engine by the corresponding number of movements and summi ng over the entire range of aircraft/engine combinations and movements for the period required.

A1.5.27 Sophisticated Aircraft Fleet and Movements2 C

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A.1.5.28 In the sophisticated approach it is assumed that the modeller has the actual and

accurate informati on on aircraft type and subtype, number and correct engine name and designation for every single movement available. The match between aircraft and engine is through the aircraft registration number in connection with the ICAO or similar engine UID (uniqu e identification number).

A.1.5.29 The total of the movements is derived from the actual movement information for each single aircraft serving the particular airport. Every movement (landing or take

- off) is logged by the aircraft's registration number in order to provide the detailed engine information. So the number of movements for a specific aircraft type might include various numbers of this type but by varying aircraft registrations numbers.

A1.6 Aircraft Main Engine Emission Calculations

A1.6.1 Fue l Flow and Emissions Indices

A1.6.2 Aircraft engines with rated power greater than 26.7 kN are emissions

- certified by ICAO for emissions of NOx, CO, and HC and maximum SN, based upon the standardised LTO cycle as set out in ICAO Annex 16, Volume II and pub lished originally in Document 9646

- AN/943 (1995) and website amendments. ICAO provides the emissions certification data on the

worldwide web at www.caa.co.uk . Updates to the Aircraft Engine Emissions Databank are made as new engines are certified. An example of the ICAO Engine Emissions Databank can be found in Appendix A.

A1.6.3 When ICAO engine data are used to calculate aircraft emissions, it is important to select the pollutant measured average value and not the pollutant characteristic level, which also is reported in the ICAO databank. The characteristic level of a gaseous pollutant or smoke is derived for certification purposes and conta ins statistical coefficients corresponding to the number of engines tested.

A1.6.4 For the vast majority of commercial aircraft engines operated at major airports, fuel flow and EI values are reported in the ICAO Aircraft Engine Emissions Databank, at the four certification thrust settings. Aircraft engine EI are reported in grams of pollutant per kilogram of fuel consumed (g/kg) and the fuel flow rates for each mode are reported in kilograms per second (kg/s). The reported EI and fuel flow values are recom mended by ICAO to be used to calculate emissions from main aircraft engines.

A1.6.5 There are other databases available that address EI and fuel flow information for aircraft engines that are not certified nor regulated by ICAO. The following are two of th e primary non

- ICAO databases.

A1.6.6 The Swedish Defence Research Agency (FOI) is the keeper of a database of EI for turboprop engines supplied by the manufacturers for the purposes of developing emissions inventories. Although the database is publicly ava ilable only through FOI, International Coordinating Council of Aerospace Industries Associations (ICCAIA) closely monitors who requests the use of the database to ensure the data is not misused. The FOI database is not endorsed by ICAO because the data are not certified and may have inaccuracies resulting primarily from the unregulated test methodologies. There is also a significant issue of an appropriate idle setting for turboprops. Therefore, whilst this data is not ICAO

- certified aircraft engine emissio n data, this information is included in this guidance document recognizing that the FOI turboprop database may assist airports in conducting emission inventories. Currently, documentation of how the EI were derived and the types of turboprop engines is una vailable.CAEP/8

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Appendix C to the Report on Agenda Item 2 2 C

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Information about turboprop engines, suggested TIM and how to obtain the data from FOI can be

found at http://www.foi.se/FOI/templates/Page____7070.aspx

A1.6.7 Switzerland‘s Fe deral Office of Civil Aviation (FOCA) has developed a methodology and a measurement system to obtain emissions data from piston

- powered aircraft and helicopters. For these engine types, there is no requirement for emissions certification; hence

the FOCA da ta is one of the few sources of data available for conducting emission inventories with respect to aircraft with these engines. However, the FOCA data has not been corroborated by ICAO, and is not endorsed by ICAO. Therefore, whilst this data is not ICAO

- c ertified aircraft engine emission data, this information is included in this guidance document recognizing that FOCA data may assist airports in conducting emission inventories for certain aircraft for which they otherwise might not have any data sources. The reader is referred to FOCA website to obtain documentation of the emissions measurement system, the consistent measurement methodology, recommendations for the use of their data to conduct simple emission inventories using suggested

TIM. All material i s openly available for download at www.bazl.admin.ch  for specialists 

environment  aircraft engine emissions.

A1.6.8 Emission Calculations Simple Approach (A)

A1.6.9 Emissions Indices

A1.6.10 In the Simple App roach (Option A), the EI is replaced with an emissions factor (EF) 5

and Table B

- 1 in Appendix B provides these emissions factors for five pollutant species for each

of the listed aircraft.

A1.6.11 The emissions factor is provided in terms of kg of each em ission species per LTO cycle per aircraft. These have been calculated based on the representative engine type for each generic aircraft type and using ICAO TIM, thrust settings and other basic assumptions. Other assumptions are described in the notes in Ta ble B

- 1 in Appendix B.

A1.6.12 Emissions Calculation

A1.6.13 For NOx, HC, CO, SO2 and CO2 there is a standard method for calculating aircraft engine emissions using the Simple Approach (Option A). For each aircraft type, multiply the number of LTO cycles of that aircraft (over the assessment period) by the emissions factor in

Table B

- 1 for each of the pollutant species and then add up the values for all the aircraft to get the amount of total emissions (in kg) for each pollutant. See the following generic equation:

Emission of Species X =  ([Number of LTO cycles) x (Emissions Factor) Eq.

A1

- 1

(in kg) All Aircraft of Aircraft Y for Species X

A1.6.14 Notably, this equation does not account for specific engine types, operational modes or TIM as it assumes that the conditions under study are the same or similar to the default data being used.

5 EI = Emission Index, expressed as g pollutant per kg fuel; EF = Emission Factor, expressed as mass of pollutant per specified unit (e.g. aircraft)2 C

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A1.6.15 If required for the inventory, a similar process is used for fuel consumption over the period under consideration using fuel consumption data in Table B

- 1:

Fuel consumption =  [Number of LTO cycles] x [Fuel Consumption] Eq.

A1

- 2

(in kg) All Aircraft of Aircraft Y

A1.6.16 There is n o provision for the calculation of PM emissions in the Simple Approach (Option A).

A1.6.17 Emission Calculation Simple Approach (B)

A1.6.18 Aircraft Time

- in

- mode

A1.6.19 As discussed previously, the reference TIM used as part of the ICAO engine

emissions certification process (and contained in the ICAO Aircraft Engine Emissions Databank) are only appropriate for the engine certification process, and are not representative of actual TIM aircraft spend in real world operations (see Annex A1.2.1 through A1.2 .8). Nonetheless, the ICAO default TIM can provide a conservative estimate of aircraft emissions at an airport when airport

- specific taxi/ground idle TIM data or refined methods of estimating takeoff, climb, and approach times are not available. Sensitivit y analyses conducted by CAEP determined that conducting an aircraft emissions inventory using the ICAO certification TIM (as well as the fuel flow and EI) normally yields an overestimation of total aircraft emissions across the entire LTO cycle.

A1.6.20 W hile ICAO default TIM are applicable primarily to regulated engines, there may other default times in mode be available for other engine types (i.e. unregulated turbofan engines, turboprop engines, piston engines or helicopters). Sources for such informati on could include

national aviation or environmental authorities.

A1.6.21 Emissions Calculation Methodology for NOx, CO, and HC

A1.6.22 Identification of the aircraft type will enable the determination of the number of engines and the appropriate engine mo dels. In turn, the engine model will determine the proper EI

to calculate aircraft emissions.

A1.6.23 To determine the NOx, CO, or HC emissions for a unique aircraft/engine combination, the following formula may be used. This method is repeated for each ai rcraft/engine type representing each TIM to establish a complete aircraft emissions inventory.

Ei j = ∑ (TIMjk*60) * (FFjk) * (EIjk) * (Nej) Eq.

A1

- 3

where:

Eij = Total emissions of pollutant i (e.g., NOx, CO, or HC), in grams, produced by aircraft type j for one LTO cycle

Eijk = The emission index for pollutant i (e.g., NOx, CO, or HC), in grams per pollutant per kilogram of fuel (g/kg of fuel), in mode k (e.g., takeoff, climb out, idle and approach) for each engine used on aircraft type j

FFjk = Fuel flow for mode k (e.g., tak eoff, climb out, idle and approach), in kilograms per second (kg/s), for each engine used on aircraft type jCAEP/8

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TIMjk = Time

- in

- mode for mode k (e.g., idle, approach, climb out, and takeoff), in minutes, for aircraft type j

Nej = Number of engines used on air craft type j

A1.6.24 If the actual measured TIM for one or more of the operating modes exists and is used, then the different flight phases have to be calculated separately and the total emissions for each species have to be summed to give the total emissi ons for each aircraft/engine type.

A1.6.25 ICAO does not have emissions certification standards for SOx. However, SOx emissions are a function of the quantity of sulphur in the fuel. The U.S. EPA conducted a survey of sulphur content for commercial aviatio n jet fuel, which resulted in a U.S. average of 1 gram per 1,000 grams of fuel consumed (EISOx = 1 g/kg of fuel). This average should not be relied upon where validated data is needed, but can be used to perform an emissions inventory of SOx

emissions usin g the following equation:

Ek = ∑ (TIMk*60) * (Erk) * (Nek) Eq.

A1

- 4

where:

Ek = Total emissions of SOx, in grams, produced by aircraft type k for one LTO cycle

Nek = Number of engines used on aircraft type k

Erk = 1 * (FFk)

where:

Erk = emission rate of total Sox in units of grams of Sox emitted per second per operational

mode for aircraft k

FFk = the reported fuel flow by mode in kilograms per second (kg/s) per operational mode for each eng ine used on the aircraft type k.

A1.6.26 ICAO does not have emissions certification standards for PM emissions. However, CAEP has developed and approved the use of an interim First Order Approximation (FOA)

method to estimate total PM emissions from certif ied aircraft engines. At the time of this document, FOA version 3 is the most up

- to

- date and is provided in Appendix D of this section. FOA3 provides expressions of volatile PM from fuel organics and sulphur content, as well as a relationship between SN an d non

- volatile PM mass. CAEP is committed to continually updating the interim FOA methodology as data and scientific advancements become available, until such time as it can be replaced by fully validated and verified measurement data. The FOA methodology is to be used for emissions inventory purposes only within the vicinity of airports. The FOA methodology should not be relied upon where accurate, validated data is required.

A1.6.27 Emission Calculation Advanced Approach (Options A and B)

A1.6.28 The a dvanced emission calculation methods make use of performance models that take into account or model ambient and specific aircraft related operational information. As such,

a number of additional information is needed that could be obtained more easily by t he

modeller from public sources. Such information can include the following: aircraft information (take

- off mass, actual engine), airport information (airfield elevation, runway usage length), ambient information (wind speed and direction, turbulence, pres sure, temperature, humidity) and operational information (destination, stand, runway, departure route, approach route and glide slope, APU usage). The actually needed information depends on the model used and may vary,

also refer to Table 1 for additional guidance on what parameters to use..2 C

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A1.6.29 Thrust Levels

A1.6.30 While the certification LTO

- cycle suggests specific thrust settings for each mode, any operational LTO

- cycle may have different modes with more individual power settings (cf. A1.3). Specif ically, take

- off thrust is often less than the certification 100% for performance and cost

efficiency reasons. Aircraft are more and more operated using flexible thrust rates, sometimes in combination with derated thrust options. This could apply to the ta ke

- off phase of a flight as well as to other flight phases in the landing and take

- off cycle.

A1.6.31 As an option A, an airport average and/or aircraft group specific reduced thrust level may be available for primarily the take

- off phase, but may also b e available for other modes. Such information could stem from empirical data, for example, from one aircraft operator, and be extrapolated over the total of the operations.

A1.6.32 In option B, a dedicated aircraft performance model should be utilised tha t gives an operational thrust level using additional, publicly available parameters unique to the model. The

thrust level could be modelled for take

- off only or for all modes in the LTO

- cycle.

A1.6.33 Time in Mode

A1.6.34 As an option A, airports are en couraged to take measurements of the typical taxi times unique to the airport's taxiway structure for both taxi

- in from runway to the terminal and

vice versa for taxi

- out times, including possible queuing times at departure runways. Using the

measured taxi time values for the study airport can better reflect emissions for the taxi/idle mode of the LTO cycle. Such data could be obtained from e.g. touch

- down, on

- block, off

- block and

take

- off times for either all possible stand/runway combinations or as an air port default.

A1.6.35 As an option B, times in mode could also be modelled for other than just the taxi mode. This option would most likely include an aircraft performance modelling approach, giving aircraft group or even aircraft type individual times in mode for those modes considered in the approach (e.g. more than just the 4 ICAO certification modes).

A1.6.36 Fuel Flow

A1.6.37 For Option A, a relationship has been developed that uses the certification fuel flow and thrust data from the ICAO Engine Emi ssions Databank to determine fuel flow at any thrust level desired between 60% and 100%. Note. The thrust levels are % of rated output thrust and represent the thrust selected by the pilot. They do not represent the actual thrust delivered by the engine (c orrected net thrust). This methodology allows for accurate calculation of fuel flow at

reduced take

- off thrust levels which in some instances could be as low as 60% of rated thrust. From this fuel flow, corresponding emissions indices can be calculated u sing the BFFM2 curve fitting methodology. A twin quadratic methodology has been developed, and it is described below;

A1.6.38 The Twin Quadratic method comprises calculation of fuel flow vs thrust, for thrusts

above 60% maximum rated thrust. The fuel flow and thrust data required to define the two curves is available in the ICAO Engine Emissions databank for certificated engines. The methodology is

as follows:CAEP/8

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- 19

60% to 85% thrust: defined by a quadratic equation based on the 7%, 30% and

85% thrust and associated fuel flow points 85% to 100% thrust: defined by a quadratic equation based on the 30%, 85% and

100% thrust and associated fuel flow points

These two quadratic equations are uniquely defined by their 3 points and meet at 85% thrust. The

slo pes of the two curves at 85% thrust may be different, (the ―kink‖ shown diagrammatically in Figure A1

- 2 below).

Figure A1

- 2 Diagrammatic illustration of twin quadratic curve fit

A1.6.39 A quadratic equation to fit through three points on the non

- dimen sionalised fuel flow versus thrust curve has the following parameters:

X = (thrust)/(maximum rated thrust), Quadratic defined by values X1, X2, X3

Y = (fuel flow)/(fuel flow @ maximum rated thrust), values Y1, Y2, Y3

Giving

Y = AX 2 + BX + C

With thr ee known points

Y1 = AX1 2 + BX1 + C

Y2 = AX2 2 + BX2 + C

Y3 = AX3 2 + BX3 + C

Allowing solution for A, B and C as :

A = (Y3

- Y1)/((X3

- X1)*(X1

- X2))

– (Y3

- Y2)/((X3

- X2)*(X1

- X2))2 C

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Appendix C to the Report on Agenda Item 2

B = (Y3

- Y1)/(X3

- X1)

– A*(X3+X1)

C = Y3

– A*X3 2

- B*X3

A,B and C vary for differ ent engine UIDs

For selected thrusts between 85% and 100% rated thrust:

Known ICAO Engine Emissions Databank points for the engine UID at 30%, 85% and 100% are used to derive A, B and C as above

.

These are then used in the generic quadratic equation

Y = AX 2 + BX + C

Where X is the (selected thrust)/(maximum rated thrust) To give Y (= (desired fuel flow)/(fuel flow at maximum rated thrust)) at the selected thrust.

Fuel flow at the selected thrust is obtained but multiplying Y by the ICAO Engine Emissi ons Databank fuel flow at maximum rated thrust

The Upper Quadratic curve is applied between 85% and 100% rated thrust only

For selected thrusts between 60% and 85% rated thrust

.

Known databank points for the engine UID at 7%, 30% and 85% are used to der ive A, B and C as

above

. These are then used in the generic quadratic equation

Y = AX 2 + BX + C

Where X is the (selected thrust)/(max rated thrust)

To give Y (= (fuel flow)/(fuel flow at maximum rated thrust)) at the selected thrust.

Fuel flow at the selected thrust is obtained by multiplying Y by the ICAO Engine Emissions

Databank fuel flow at maximum rated thrust

The Lower Quadratic curve is applied between 60% and 85% rated thrust only

Example calculation for UID 8RR044, Rolls

- Royce Trent 553

- 61:

1 ) Determination of quadratic curve between 85% and 100% rated thrust

X1 = 0.30

X2 = 0.85

X3 = 1.00

With ICAO Engine Emissions Databank fuel flows:

Y1 = 0.2844CAEP/8

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Y2 = 0.8199

Y3 = 1.0000

→ A = 0.3242

→ B = 0.6009

→ C = 0.07491

→ Y = 0.3242 X 2 + 0.6009 X + 0 .0749 (1)

2 ) Determination of quadratic curve between 60% and 85% thrust

X1 = 0.07

X2 = 0.30

X3 = 0.85

With ICAO Engine Emissions Databank fuel flows:

Y1 = 0.1090

Y2 = 0.2844

Y3 = 0.8199

→ A = 0.2709

→ B = 0.6622

→C = 0.0613

→ Y = 0.2709 X 2 + 0.6622 X + 0.0613 (2)

3 ) Results for selected thrust (examples)

70% thrust (X = 0.7): equation (2): Y = 0.6576 → multiply with ICAO Engine Emissions Databank maximum rated thrust fuel flow → Fuel flow = 1.388 kg/s

90% thrust (X = 0.9): equation (1): Y = 0.87 83 → multiply with ICAO Engine Emissions Databank maximum rated thrust fuel flow → Fuel flow = 1.853 kg/s

A1.6.40 For Option B, performance model would be utilized to obtain/calculate operational fuel flow data using various additional data (e.g. ATOW or stage length or information pertinent to fuel flow calculation) in conjunction with the ICAO EEDB. As examples, models such as BADA or PIANO or ADAECAM may be used

A1.6.41 Emission Indices

A1.6.42 Option A: Emissions indices for Option A will be cal culated from the data in the ICAO EEDB using the  ̳linear interpolation on a log

- log scale‘ method as employed in the BFFM2 method, using the fuel flows calculated by the methodology in section A1.6.39.2 C

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Appendix C to the Report on Agenda Item 2

A1.6.43 Option B: The "operational" emission indices are derived from the data in the ICAO EEDB using the  ̳linear interpolation on a log

- log scale‘ method as employed in the BFFM2 method, using the operational fuel flows from the method described in section A1.6.40

A1.6.44 Application of Additional Paramet ers that may Influence Emissions, if Appropriate

A1.6.45 Important Caveats For Modelers Using Advanced Methods

A1.6.46 Unlike for the Simple approach, different methods under the heading of Advanced methods may already include some aspects of the correcti ons for additional parameters such as ambient conditions. It is important to avoid double

- accounting in these cases. Hence, the application of the corrections may differ between different methods. It is also important to realize

that ambient conditions suf ficiently far from standard may cause the airplane or engine to reach operational limits. For instance, many engines will not be able to provide full flat

- rated thrust beyond some temperature limit (typically ISA +15C, but this limit varies). The modeler m ust take care not to extrapolate a methodology beyond the conditions for which it is valid.

A1.6.47 Application to Advanced Approach Option B

–

A1.6.48 If an aircraft performance model is used to calculate airplane and engine operating conditions (Advanc ed Option B), then it should already include the effects of forward speed on the fuel flow. It may, depending on the model, also include the effects of ambient conditions. The modeler must be aware of how the model functions. If it is necessary to correct the airplane performance model and/or fuel flow further to account accurately for these effects, the modeler should do so at this stage.

A1.6.49 After the airplane performance and fuel flow has been correctly determined under Advanced Option B, then the e missions indices should be calculated using a fuel flow method.

One documented 6 fuel flow method is the Boeing Fuel Flow Method 2. Depending on the needs of the modeler and the available data other methods may be used, although the BFFM2 is

recommended as a default option.

A1.6.50 As described in SAE AIR5715, the BFFM2 accounts for the effects of ambient conditions and forward speed. It is important to recognize that if the effects of ambient conditions and forward speed are to be considered, it is not suf ficient to only use the initial calculation of the emission indices from the curve fitting methods defined for the BFFM2. However, the full BFFM2 method includes corrections for both of these effects, so no further corrections to the

emissions indices woul d be required if it is used.

A1.6.51 Application to Advanced Approach Option A

A1.6.52 Methods that fall under Advanced Option A, while less sophisticated and precise, may also be more complicated to adjust for ambient conditions. First the performance of the airplane (thrust, time in mode, etc.) might need to be adjusted to account of ambient conditions. Then,

6 SAE AIR5715CAEP/8

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Appendix C to the Report on Agenda Item 2 2 C

- 23

since the fuel flow would have been calculated for the relevant thrust level at ISA static conditions (as the fuel flow is not based on an aircraft performance model in this option), corrections for both ambient conditions and forward speed would need to be implemented. The result would be a fuel flow, corrected for both sets of conditions, but without the accuracy (or temporal and spatial resolution ) of an Option B model.

A1.6.53 The calculation of the emission indices and their correction for ambient conditions and forward speed effects could then use the same approach as for Advanced Option B. However, because the fuel flow and flight conditions a re not known to the same degree of resolution as with Option B, the results obtained when applying a method such as the BFFM2 might not be accurate

or even well

- defined. The BFFM2 is only defined at fully specified 7 flight conditions and can not

be directl y applied to an entire ―mode‖ such as takeoff or climbout. Either a fully specified flight condition could be assumed that represents the airplane for the entire time in mode, or else a

different method would have to be used to determine the emissions indi ces. This different method might be a modification of BFFM2, or it might be unrelated. Thus the application of corrections for forward speed and ambient conditions to an Advanced Option A calculation will depend on the details of the model and the requirem ents of the modeler.

A1.6.54 Altitude Effects

A1.6.55 The effects of altitude on an aircraft engine are governed by the local pressure, temperature and humidity. Therefore, the effects of altitude on the engine emissions will be correctly treated if the a pproaches described above are implemented and the ambient conditions used are those local to the airplane in flight.

A1.6.56 Engine Deterioration

A1.6.57 While aircraft/engine manufacturers always design their products for peak efficiency at delivery, as aircraft enter revenue service some performance degradation may be experienced over time due to the harsh environments aircraft and engines will operate at. Erosion, seal degradation and dirt build up on finely tuned rotating hardware and airframes over long periods of time can lead to performance loss. If left unchecked, the deterioration can result in noticeable fuel consumption increases over time. Fuel consumption increases are an un

- necessary cost increase to the carriers and as a result they will normally perform maintenance on their products to keep the level of performance loss at acceptable levels. An analysis done by CAEP Working Group 3 has assessed the impact of aircraft/engine deterioration and provides the following guidance regarding how and when to apply deterioration in performing airport inventories.

A1.6.58 In

- service airframe and engine deterioration for the purposes of airport inventories (i.e., the LTO cycle below 3000 feet) is a small but real effect on fuel burn and NOx emission s. There is no evidence that indicates deterioration effects on CO, HC, or smoke number.

7 Fully Specified: The state vector (3D position, speed, attitude), engine par ameters and airframe configuration are known.2 C

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Appendix C to the Report on Agenda Item 2

A1.6.59 As a cost savings measure airlines take precautions to keep deterioration effects to a minimum by establishing routine maintenance programs. Based on analys es of theoretical and actual airline data, the magnitude of deterioration effects can be on a fleet

- wide basis as follows:

Fuel consumption +3%

NOx emissions +3%

CO emissions no change

HC emissions no change

Smoke number no change

A1.6.60 For application to modelling, including emission inventories, the appropriate use of this deterioration information in modelling activities is model/assumption and input data dependent. Specifically, models and assumptions may already include a deterioration allowance, either explicitly (i.e., actual engine operational data or calibrated/validated on actual in

- service data), implicitly (i.e., conservative fuel flow correction factors applied to engine certification values), or may already include conservatism which significantly outweighs the fuel consumption and NOx emissions deterioration effects. Care must be taken to avoid double accounting.

A1.6.61 The Simple Approach is a significant over

- estimate of aircraft emissions and fuel consumption. The margin of conservatism for the Simple Approach is large enough to preclude the application of deterioration effects.

A1.6.62 The Advanced Approach allows different thrust settings to be applied to fuel flow methodologies as well as some sort of aircraft perform ance calculations. While the results are more accurate than the Simple Approach, comparison with FDR data suggests that, for commonly used methods, there still is a level of conservatism on a fleet

- wide basis on fuel flow calculations resulting from use o f performance

- estimated times

- in

- mode, take

- off weight and throttle settings in the LTO cycle. The deterioration factors are considered smaller that the inherent conservatism already existing in the method and application is therefore not recommended.

A 1.66.3 Where the Sophisticated Approach utilizes actual engine/aircraft operational performance data (including operational fuel flow), then that would inherently include actual deterioration effects. Again the application of deterioration factors is not r ecommended.

A1.6.64 An exception to the recommendation above might occur in using a combination of advanced and sophisticated methods using actual engine/aircraft combinations, average or

measured times

- in

- mode, TOW and throttle settings, combined with f uel flow rates calculated from ICAO certification data. In this case application of deterioration factors is recommended.

A1.6.65 Fuel consumption deterioration should only be applied to modelling in the vicinity of airports (i.e., the LTO cycle) and shoul d not be used for global modelling where the deterioration factor would be different than the values reported here.

A1.6.66 Start

- Up Emissions Calculation ApproachCAEP/8

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Appendix C to the Report on Agenda Item 2 2 C

- 25

A1.6.67 During the starting sequence there is very little NOx emissions produced compared to the LTO cycle due to the very low engine temperatures and pressures, and the only emissions that requires consideration during the starting sequence is HC. Aircraft main engine starting can generally be broken down into two phases; pre ignition and post ignition.

A1.6.68 Engine Pre

- Ignition

A1.6.69 The Pre

- ignition phase represents the time when the engine has been cranked using a starter motor and fuel permitted into the combustor to achieve ignition. From starter motor initiation to combustor lighti ng can take several seconds but there is no fuel entering the engine as the fuel system primes and the fuel valves are closed. Due to the requirement for quick start times, the combustion system is designed so that ignition occurs within the first or secon d spark of the igniter, typically within 1 second of fuel valves being opened and no later than 2 seconds. This has also been confirmed from rig testing by manufacturers using optical access to see fuel arrive and observed time to ignition.

A1.6.70 Pre i gnition emissions would be purely fuel hydrocarbons, as combustion has not

been initiated so no fuel is consumed within the combustor. This allows the HC emissions to be calculated directly from the fuel flow. During the pre ignition period three things h appen

 The fuel valve is opened

 The fuel injector system fills and fuel flow starts

 The igniter begins to spark and lights the combustor

A1.6.71 Engine Post

- Ignition

A1.6.72 At this point the starting process occurs at low engine loading conditions. At these operating points the engine emissions will primarily take the form of HC and CO emissions. Direct measurement of starting emissions is made difficult by unburnt and partially burnt fuel contaminating gas sampling hardware. After ignition at particul arly low engine loading, as would be the case during engine starting, emissions of HC dominate. For this reason it is not unreasonable to attribute starting emissions to HC alone resulting in a conservative estimate of HC emissions. CO emissions can be hig her than HC for some engines at 7% idle and below, and thus post ignition HC emissions may be significantly lower than the estimate based on combustion efficiency. Detailed emissions measurements would be required to provide a more precise estimate of HC emissions.

A1.6.73 Post ignition emissions are determined from the point of ignition through the acceleration to idle. As the combustor is now burning fuel therefore the rate of consumption must be considered to determine emissions accurately. Gas sampli ng at sub

- idle conditions is very difficult on engines because there are significant amounts of unburned and partially burnt fuel that tends to contaminate the sampling hardware. To get around this issue the analysis is performed using combustion efficien cy correlations that have been determined by combustor rig testing at sub

- idle conditions. These correlations are based on combustor inlet temperature, combustor inlet pressure, combustor air mass flow, fuel flow and fuel

- air ratio. This approach to

determ ining combustion efficiency and heat release is common between all engine manufacturers.2 C

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Appendix C to the Report on Agenda Item 2

A1.6.74 The instantaneous combustor efficiency is calculated and the resulting inefficiency is allocated as a percentage of unburnt fuel representing the resulting HC emission. Using this process throughout the acceleration to idle the sum of the instantaneous HC emissions can be utilized to provide a conservative estimation of the total post ignition engine HC emission.

A1.6.75 ICCAIA has performed a detailed analysis of engine starting data from GE, RR , P&W and IAE engines and has developed a method to estimate total start up emissions based on the rated sea level thrust of the engine in question. The results of this study were presented to CAEP WG3 in Working Paper CAEP8

- WG3

- CETG

- WP06. In the paper ICCAIA recommends a simple first order linear relationship between HC and the take

- off engine thrust rating. The recommended equation is:

STARTING HC EMISSIONS (grams) = Rated Take Off Thrust (kN)/2 + 80 Eq. A1

- 5

(NOT E: This analysis is based on actual engine testing performed at moderate inlet temperature conditions. The methodology to derive the starting HC emissions was conservative because it did not account for any CO during starting. In addition, applying the methodology to all engines may be optimistic for older engines where fuel distribution controls are not as sophisticated. The methodology also considers typical times to light and typical starting times which in practice could be quite varied and would be longer at very cold conditions. It would be reasonable to state that the uncertainty in the methodology was around +/

- 50%)

.

A1.6.76 Advanced Calculation Methodology for NOx, CO and THC

A1.6.77 The calculation of emission masses in the advanced approach ma kes use of additional data, information and existing models. As such, the emission of an aircraft is a function (  ) of the key parameters and the chosen options. This results in having a performance based calculation using various additional data and infor mation that should yield a more accurate emissions inventory that will be unique to the specific airport and study year under consideration.

A1.6..78 To determine the NOx, CO, or HC emissions for a unique aircraft/engine combination, the following formula may be used. This method is repeated for each aircraft/engine type and movement.

Ei j = ∑ (TIM

jk *60) *  (FF

jk , EI jk or Thrust

jk , Cond

j , Ne j ) Eq.

A1

- 6

where:

Eij = Total emissions of pollutant i ( e.g., NOx, CO, or HC), in grams, produced by a specific aircraft j for one LTO cycle

Eijk = The emission index for pollutant i (e.g., NOx, CO, or HC), in grams of pollutant per kilogram of fuel (g/kg of fuel), in mode k for each engine used on aircraft j

FFjk = Fuel flow for mode k, in kilograms per second (kg/s), for each engine used on aircraft type j

Thrustjk = Thrust level for mode k for the aircraft type j

TIMjk = Time

- in

- mode for mode k, in minutes, for aircraft jCAEP/8

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Nej = Number of engines used on air craft j, considering the potential use of less than all engines during taxi operation.

Condj = ambient conditions (forward speed, altitude, p, t, h) for aircraft type j movement

A1.6.79 Emission Calculation Sophisticated Approach

A1.6.80 Parameters

A1.6.8 1 Under the Sophisticated Approach, the actual and refined data required for the analysis is obtained from real

- time measurements, reported performance information and/or complex computer modeling outputs. At a high level, these data and information charac terize the actual fleet composition in terms of aircraft types and engine combinations, TIM, thrust levels, fuel flows and possibly, combustor operating conditions for all phases of ground

- based and take

off operations. In some cases, correction of engine operating conditions to reference conditions, using accepted methods will also be required. 8 Additionally, the application of the parameters

defined in Sections A1.6.42

– A1.6.65 could be considered based on the guidance provided in

Table 1.

A1.6.82 Liste d below are the data and information typically required for computing aircraft engine emissions using the Sophisticated Approach.

 Times

- in

- mode measurements for different aircraft/engine types under different load, route and meteorological conditions.

 Rev erse thrust deployment measurements for different aircraft/engine types under different meteorological conditions.

 Airport meteorological conditions, where modelling of aircraft/engine performance accounts for variation in meteorological conditions.

 Freque ncy and type of engine test runs.

 Frequency of operational aircraft towing.

 Airport infrastructure and constraints (e.g., runway length).

A1.6.83 Similarly, data measured by operators may be made available, including:

 Typical or actual throttle settings us ed during reverse thrust operation.

 Actual aircraft/engine configuration data.

 Actual fuel flow data.

 Actual idle engine

- type idle speeds.

 Typical or actual throttle settings for approach take off and climb out (e.g. reduced thrust

take

- off procedures).

 Ap proach and climb profiles.

 Frequency of less than

- all

- engine taxi operation.

A1.6.84 This measured and actual operator data may supplement or replace elements of

modeled data.

8 Sources for correcting and obtaining these data will be the airlines, engine manufacturers, ICAO Annex 16 Volume II, SAE AIR 1845, BADA, and ETMS, ETFMS and FDR data.2 C

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Appendix C to the Report on Agenda Item 2

A1.6.85 Using actual performance and operational data, engine emissions factors can be calculated using programs such as the Boeing Fuel Flow Method 2 or the Deutsches Zentrum für

Luft

- und Raumfahrt Method.

A1.6.86 Sophisticated Calculation Methodology for NOx, CO and THC

A1.6.86 Once the actual fleet engine emissions factors, time s

- in

- mode and fuel flows are known, the LTO emissions are calculated using the same equation used in the Advanced Approach; however with the refined input values.

Ei j = ∑ (TIM

jk *60) *  (FF

jk , EI jk or Thrust

jk , Cond

j , Ne j ) Eq.

A1

- 7

where:

Eij = Total emissions of pollutant i (e.g., NOx, CO, or HC), in grams, produced by a specific aircraft j for one LTO cycle

Eijk = The emission index for pollutant i (e.g., NOx, CO, or HC), in grams per pollutant

p er kilogram of fuel (g/kg of fuel), in mode k for each engine used on aircraft j

FFjk = Fuel flow for mode k, in kilograms per second (kg/s), for each engine used on aircraft type j

Thrustjk = Thrust level for mode k for the aircraft type j

TIMjk = Time

- i n

- mode for mode k, in minutes, for aircraft j

Nej = Number of engines used on aircraft j

Condj = ambient conditions (forward speed, altitude, p, t, h) for aircraft type j movement

A1.7 Auxiliary Power Unit Emissions

A1.7.1 An auxiliary power unit (APU) is a small gas

- turbine engine coupled to an electrical generator and is used to provide electrical and pneumatic power to aircraft systems when required. It is normally mounted in the tail cone of the aircraft, behind the rear pressure bulkhead,

and runs on kerosene fed from the main fuel tanks. Not all aircraft are fitted with APU, and though their use on transport category jet aircraft is now almost universal, some turboprops and business jets do not have an APU fitted.

A1.7.2 Emissions Calculation Method ology

A1.7.3 Unlike aircraft main engines, APU are not certificated for emissions and the manufacturers generally consider information on APU emissions rates as proprietary. As a result, little data are publicly available to serve as a basis for calculatin g APU emissions. Analysis performed to date on APU‘s have not been successful in developing Advanced and Sophisticated methodologies that more accurately predict APU emissions if more information is available to the user. As a result, use of the Simple a pproach, for all cases, is recommended at this time.

A1.7.4 Simple Approach

A1.7.5 If very little information is known about the aircraft types operating at the study airport, then the Simple Approach for APU emissions may be used. However, the results areCAEP/8

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Appendix C to the Report on Agenda Item 2 2 C

- 29

likely to have a large order of uncertainty associated with their use and emissions. Generalised emissions for APU have been made public. The information is recommended for use as the Simple approach uses averaged proprietary engine

- specific values obt ained from APU

manufacturers

A1.7.6 Where the level of detail of aircraft fleet does not allow for this process to be used, the following values are considered representative of the APU emissions for each aircraft operation at the airport under study (othe r values may be used if deemed more appropriate):

Aircraft Group Short

- haul 9 Long

- haul

Duration of APU operation 45 min. 75 min.

Fuel burn 80 kg 300 kg

NOx emissions 700 g 2400 g

HC emissions 30 g 160 g

CO emissions 310 g 210 g

PM10 emissions 25 g 4 0 g

A1.7.7 The previous fuel burn and emission values are based on averaged manufacturer

APU

- specific proprietary data; though do not represent any specific APU type. The operational times noted are based on average operating times experienced by a numbe r of operations and do not necessarily represent any specific airport operation. It should be noted that APU operating times vary considerably at different airports due to a number of factors, and can be significantly

different to the default values listed in the previous table. If information on actual APU operating times is available, either from surveys or as maximum durations from local airport restrictions, then the APU fuel burn and emissions may be adjusted by factoring these values in the table by

t he ratio of the survey times with the default values outlined.

A1.7.8 For example, APU NOx emissions for a short

- haul aircraft operating for 60 minutes

would be calculated as follows:

NOx (g/LTO) = (60 minutes per LTO)) x (700 g/ 45 minutes) = 933 g/LTO

A1 .7.9 In addition, publicly distributed manufacturer information is available showing aircraft and APU combinations including duty cycle average APU EI and fuel burn rates. 10 Air Transport Association (ATA) estimates of APU operating times also are available ; based on a limited, informal survey concerning APU usage. Use of the manufacturer APU emissions data, along with the ATA estimates on APU operating times will provide a more accurate estimate of APU emissions. The ATA estimates on APU operating times pro vide estimates for narrow and wide

body 11 aircraft with and without gate power. As examples, these estimates are provided in the following table (other values may be used if deemed more appropriate):

9 Although there is no common definition of short haul and long haul, in the context of this document we propose a rule of thumb that relates the term to aircraft type. The long haul group would include aircraft capable of a maximum range of more than 8000km, e.g. A330, A4340, A380, B747, B767

- 2 00ER, B763, B764, B777, IL96, MD11. Short

haul would include all other aircraft.

10 Correspondence from Honeywell Engines & Systems to U.S. EPA Assessment and Standards Division, APU Emissions, September 29, 2000.

11 Narrow Body: single aisle aircraft. Wide body: multiple aisle aircraft e.g. A300, A330, A340, A380, B767, B777,

B747.2 C

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Appendix C to the Report on Agenda Item 2

ATA Operating Time (hours/cycle)

Aircraft Type With Ga te Power Without Gate Power

Narrow Body 0.23 to 0.26 0.87

Wide Body 0.23 to 0.26 1.0 to 1.5

A1.7.10 APU and aircraft combinations can be found in 1995 FAA technical report entitled, Technical Data to Support FAA Advisory Circular on Reducing Emissions from Commercial Aviation [FAA 1995]. This document provides an accurate summary of which major APU family is used on different aircraft. The document also provides modal EI and fuel flow for specific APU; all of which would provide additional detail to the APU emissions calculation.

A1.7.11 For example, APU NOx emissions for a wide body aircraft utilizing a 331

- 200ER without gate power, where the time at load is 1.5 hours, the NOx EI is 9.51 lb per 1000 lb fuel, and the fuel flow is 267.92 lb per hour.

NOx (lb/LTO) = (1.5 hours per LTO)) x (9.51 lb/1000 lb fuel)*(267.92 lb fuel/hour) = 3.82 lb/LTO = 3,466 g/LTOCAEP/8

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- 31

Chapter 2

Emissions Inventory

Annex 1

Aircraft Emissions Appendix A Example ICAO Engine Emissions Datasheet2 C

- 32 CAEP/8

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Appendix C to the Report on Agenda Item 2CAEP/8

- WP/80

Appendix C to the Report on Agenda Item 2 2 C

- 33

Cha pter 2 Emissions Inventory

Annex 1

Aircraft Emissions Appendix B Simplified Aircraft Emission Indices2 C

- 34 CAEP/8

- WP/80

Appendix C to the Report on Agenda Item 2

Table B

- 1 LTO Emission Factor by Aircraft

LTO emissions factors/airplane (kg/LTO/aircraft) (10) Fuel consumption (kg/LTO/aircraft)

Aircraft ( 11) CO 2 (9) HC NO

x CO SO 2 (8)Source: ICAO (2004)(1)Large Commercial Aircraft(2) A300 5450 1.25 25.86 14.80 1.72 1720

A310 4760 6.30 19.46 28.30 1.51 1510

A319 2310 0.59 8.73 6.35 0.73 730

A320 2440 0.57 9.01 6.19 0.77 770

A321 3020 1.42 1 6.72 7.55 0.96 960

A330

- 200/300 7050 1.28 35.57 16.20 2.23 2230

A340

- 200 5890 4.20 28.31 26.19 1.86 1860

A340

- 300 6380 3.90 34.81 25.23 2.02 2020

A340

- 500/600 10660 0.14 64.45 15.31 3.37 3370

707 5890 97.45 10.96 92.37 1.86 1860

717 2140 0.05 6.68 6.78 0.68 680

727

- 100 3970 6.94 9.23 24.44 1.26 1260

727

- 200 4610 8.14 11.97 27.16 1.46 1460

737

- 100/200 2740 4.51 6.74 16.04 0.87 870

737

- 300/400/500 2480 0.84 7.19 13.03 0.78 780

737

- 600 2280 1.01 7.66 8.65 0.72 720

737

- 700 24 60 0.86 9.12 8.00 0.78 780

737

- 800/900 2780 0.72 12.30 7.07 0.88 880

747

- 100 10140 48.43 49.17 114.59 3.21 3210

747

- 200 11370 18.24 49.52 79.78 3.60 3600

747

- 300 11080 2.73 65.00 17.84 3.51 3510

747

- 400 10240 2.25 42.88 26.72 3.24 3240

75 7

- 200 4320 0.22 23.43 8.08 1.37 1370

757

- 300 4630 0.11 17.85 11.62 1.46 1460

767

- 200 4620 3.32 23.76 14.80 1.46 1460

767

- 300 5610 1.19 28.19 14.47 1.77 1780

767

- 400 5520 0.98 24.80 12.37 1.75 1750

777

- 200/300 8100 0.66 52.81 12.76 2.56 2560

DC

- 10 7290 2.37 35.65 20.59 2.31 2310

DC

- 8

- 50/60/70 5360 1.51 15.62 26.31 1.70 1700

DC

- 9 2650 4.63 6.16 16.29 0.84 840

L

- 1011 7300 73.96 31.64 103.33 2.31 2310

MD

- 11 7290 2.37 35.65 20.59 2.31 2310

MD

- 80 3180 1.87 11.97 6.46 1.01 1010

MD

- 90 2760 0.06 10.76 5.53 0.87 870

TU

- 134 5860 35.97 17.35 55.96 1.86 1860

TU

- 154

- M 7040 17.56 16.00 110.51 2.51 2510

TU

- 154

- B 9370 158.71 19.11 190.74 2.97 2970Regional Jets/BusinessJets > 26.7 kN thrust RJ

- RJ85 950 0.67 2.17 5.61 0.30 300

BAE 146 900 0.70 2.03 5.59 0.29 290

CRJ

- 100ER 1060 0.63 2.27 6.70 0.33 330

ERJ

- 145 990 0.56 2.69 6.18 0.31 310

Fokker 100/70/28 2390 1.43 5.75 13.84 0.76 760

BAC111 2520 1.52 7.40 13.07 0.80 800

Dornier 328 Jet 870 0.57 2.99 5.35 0.27 280CAEP/8

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Appendix C to the Report on Agenda Item 2 2 C

- 35

Gulfstream IV 2160 1.37 5.63 8.88 0.68 680

Gulfstream V 1890 0.31 5.58 8.42 0.60 600

Yak

- 42M 1920 1.68 7.11 6.81 0.61 610Source:FAEED222(3)Low Thrust Jets (Fn< 26.7 kN)

Cessna 525/560 1060 3.35 0.74 34.07 0.34 340Source: FOI(4)Turboprops Beech King Air (5) 230 0.64 0.30 2.97 0.07 70

DHC8

- 100 (6) 640 0.00 1.51 2.24 0.20 200

ATR72

- 500 (7) 620 0.29 1.82 2.33 0.20 200

Notes: (1) ICAO (International Civil Aviation Organization) Engine Exhaust Emissions Data Bank (200 4) based on average measured certification

data

. Emissions factors apply to LTO cycle only. Total emissions and fuel consumption are calculated based on ICAO standard time in mode and

thrust levels.

(2) Engine types for each aircraft were selected on a basis of the engine with the most LTOs as of 30 July 2004 (except 747

- 300

- see text). This approach, for some engine types, may underestimate (or overestimate) fleet emissions which are not directly related to f uel consumption (eg NOx, CO, HC ). (3) U.S. Federal Aviation Administration (FAA) Emissions and Dispersion Modeling System (EDMS) non

certified data (4) FOI (The Swedish Defense Research Agency) Turboprop LTO Emissions database non

certified data (5) Representative of Turboprop air craft with shaft horsepower of up to 1000 shp/engine (6) Representative of Turboprop aircraft with shaft horsepower of 1000 to 2000 shp/engine (7) Representative of Turboprop aircraft with shaft horsepower of more than 2000 shp/engine (8) The s ulphur content of the fuel is assumed to be 0.05% [Same assumption as in 1996 IPCC NGGIP revision] (9) CO2 for each aircraft based on 3.16 kg CO2 produced for each kg fuel used, then rounded to the nearest 10 kg. (10) Information regarding the uncerta inties associated with the data can be found in the following references: QinetiQ/FST/CR030440 ―EC

- NEPAir: Work Package 1 Aircraft engine emissions certification

– a review of the development of ICAO Annex 16, Volume II‖, by D H Lister and P D Norman

I CAO Annex 16 ―International Standards and Recommended Practices Environmental Protection‖, Volume II ―Aircraft Engine Emissio ns‖, 2nd edition (1993) (11) Equivalent aircraft are contained in

Table B

- 32 C

- 36 CAEP/8

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Appendix C to the Report on Agenda Item 2

Table B

- 2 Engine Designations by Aircraft

Ai rcraft ICAO Engine Engine UID

A300 PW4158 1PW048

A310 CF6

- 80C2A2 1GE016

A319 CFM56

- 5A5 4CM036

A320 CFM56

- 5A1 1CM008

A321 CFM56

- 5B3/P 3CM025

A330

- 200/300 Trent 772B

- 60 3RR030

A340

- 200 CFM56

- 5C2 1CM010

A340

- 300 CFM56

- 5C4 2CM015

A340

- 500/600 TRENT 55 6

- 61 6RR041

707 JT3D

- 3B 1PW001

717 BR700

- 715A1

- 30 4BR005

727

- 100 JT8D

- 7B 1PW004

727

- 200 JT8D

- 15 1PW009

737

- 100/200 JT8D

- 9A 1PW006

737

- 300/400/500 CFM56

- 3B

- 1 1CM004

737

- 600 CFM56

- 7B20 3CM030

737

- 700 CFM56

- 7B22 3CM031

737

- 800/900 CFM56

- 7B26 3CM033

747

- 100 JT9D

- 7A 1PW021

747

- 200 JT9D

- 7Q 1PW025

747

- 300 JT9D

- 7R4G2(66%) RB211

- 524D4(34%) 1PW029(66%) 1RR008(34%)

747

- 400 CF6

- 80C2B1F 2GE041

757

- 200 RB211

- 535E4 3RR028

757

- 300 RB211

- 535E4B 5RR039

767

- 200 CF6

- 80A2 1GE012

767

- 300 PW4060 1PW043

767

- 400 C F6

- 80C2B8F 3GE058

777

- 200/300 Trent 892 2RR027

DC

- 10 CF6

- 50C2 3GE074

DC

- 8

- 50/60/70 CFM56

- 2C1 1CM003

DC

- 9 JT8D

- 7B 1PW004

L

- 1011 RB211

- 22B 1RR003

MD

- 11 CF6

- 80C2D1F 3GE074

MD

- 80 JT8D

- 217C 1PW018

MD

- 90 V2525

- D5 1IA002

TU

- 134 D

- 30

- 3 1AA001

TU

- 154

- M D

- 30

- KU

- 154

- II 1AA004

TU

- 154

- B NK

- 8

- 2U 1KK001

RJ

- RJ85 LF507

- 1F,

- 1H 1TL004

BAE 146 ALF 502R

- 5 1TL003

CRJ

- 100ER CF34

- 3A1 1GE035

ERJ

- 145 AE3007A1 6AL007

Fokker 100/70/28 TAY Mk650

- 15 1RR021

BAC111 Spey

- 512

- 14DW 1RR016

Dornier 328 Jet PW306B 7PW078

Gu lfstream IV Tay MK611

- 8 1RR019CAEP/8

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Appendix C to the Report on Agenda Item 2 2 C

- 37

Gulfstream V BR700

- 710A1

- 10 4BR008

Yak

- 42M D

- 36 1ZM001

Cessna 525/560 PW545A or similar FAEED222

Beech King Air PT6A

- 42 PT6A

- 42

DHC8

- 100 PW120 or similar PW120

ATR72

- 500 PW127F or similar PW127F2 C

- 38 CAEP/8

- WP/80

Appendix C to the Report on Agenda Item 2

Table B

- 3 Represent ative Aircraft

Generic Aircraft ICAO IATA

aircraft in group

Airbus A300 A30B AB3

A306 AB4

AB6

ABF

ABX

ABY

Airbus A310 A310 310

312

313

31F

31X

31Y

Airbus A319 A319 319

A318 318

Airbus A320 A320 320

32S

Airbus A321 A3 21 321

Airbus A330

- 200 A330 330

A332 332

Airbus A330

- 300 A330 330

A333 333

Airbus A340

- 200 A342 342

Airbus A340

- 300 A340 340

A343 343

Airbus A340

- 500 A345 345

Airbus A340

- 600 A346 346

Boeing 707 B703 703

707

70F

70M

Boeing 717 B712 7 17

Boeing 727

- 100 B721 721

72M

Boeing 727

- 200 B722 722

727CAEP/8

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Appendix C to the Report on Agenda Item 2 2 C

- 39

72C

72B

72F

72S

Boeing 737

- 100 B731 731

Boeing 737

- 200 B732 732

73M

73X

Boeing 737

- 300 B733 737

73F

733

73Y

Boeing 737

- 400 B734 737

734

Boeing 737

- 500 B73 5 737

735

Boeing 737

- 600 B736 736

Boeing 737

- 700 B737 73G

73W

Boeing 737

- 800 B738 738

73H

Boeing 737

- 900 B739 739

Boeing 747

- 100 B741 74T

N74S 74L

B74R 74R

B74R 74V

Boeing 747

- 200 B742 742

74C

74X

Boeing 747

- 300 B743 743

74D

Boeing 747

- 400 B744 747

744

74E

74F

74J

74M

74Y

Boeing 757

- 200 B752 757

75F

75M2 C

- 40 CAEP/8

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Appendix C to the Report on Agenda Item 2

Boeing 757

- 300 B753

Boeing 767

- 200 B762 762

76X

Boeing 767

- 300 B763 767

76F

763

76Y

Boeing 767

- 400 B764

Boeing 777

- 200 B772 777

772

Boeing 777

- 300 B773

773

Douglas DC

- 10 DC10 D10

D11

D1C

D1F

Douglas DC

- 10 DC10 D1M

D1X

D1Y

Douglas DC

- 8 DC85 D8F

DC86 D8L

DC87 D8M

D8Q

D8T

D8X

D8Y

Douglas DC

- 9 DC9 DC9

DC91 D91

DC92 D92

DC93 D93

DC94 D94

DC95 D95

D9C

D9F

D9X

Lockheed L

- 1011 L101 L10

L11

L15

L1F

McDonnell Douglas MD11 MD11 M11

M1FCAEP/8

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Appendix C to the Report on Agenda Item 2 2 C

- 41

M1M

McDonnell Douglas MD80 MD80 M80

MD81 M81

MD82 M82

MD83 M83

MD87 M87

MD88 MD88

McDonnell Douglas MD90 MD90 M90

Tup olev Tu134 T134 TU3

Tupolev Tu154 T154 TU5

Avro RJ85 RJ85 AR8

ARJ

BAe 146 B461 141

B462 142

B463 143

146

14F

14X

14Y

14Z

Embraer ERJ145 E145 ER4

ERJ

Fokker 100/70/28 F100 100

F70 F70

F28 F21

F22

F23

F24

F28

BA C 111 BA11 B11

B12

B13

B14

B15

Dornier Do 328 D328 D38

Gulfstream IV / V GRJ

Yakovlev Yak 42 YK42 YK22 C

- 42 CAEP/8

- WP/80

Appendix C to the Report on Agenda Item 2

Chapter 2 Emissions Inventory

Annex 1

Aircraft Emissions Appendix C Definition of Publicly Available Databases for Use in the

Matchin g Aircraft Type with Engine TypeCAEP/8

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Appendix C to the Report on Agenda Item 2 2 C

- 43

Useful data fields in the IOAG Database:

LveTime = time flight is scheduled to depart origin in local time

LveGMT = time flight is scheduled to depart origin in Greenwich Mean Time

(GMT)

ArrCode = number representi ng arrival airport

Arrive = arrival airport alphabetic code (e.g., JFK)

ArrTime = time flight is scheduled to arrive in local time

ArrGMT = time flight is scheduled to arrive in GMT Equip = type of aircraft, in code (e.g., B738)

FAACarr = abbrevi ation for air carrier name

FltNo = flight number Freq = 1/0 code showing days of the week that that flight flies that time slot

and city pair

ATACarr = carrier name in Air Transport Association Code

IOAGCARR = air carrier company in 2

- letter IOAG code CarrType = commuter or carrier company ATAEquip = aircraft type in ATA code EqType = J for Jet, T for Turboprop, P for propeller

- driven aircraft

CarrName = air carrier company name spelled out LveCity = origin city and country/state, spelled out ArrCntry = destination country or state if the destination is in the US LveCntry = origin country or state if the origin is in the US

YYMM = year and month of the current schedule Eday = 0/1 code indicating whether this flight flies on each da y of the month

given by the schedule

FPM = number of times (days) this fight is flown between this city

- pair at this

time slot in a month

Useful data fields in the BACK World Fleet Registration Database:

 Aircraft Type

 Aircraft Serial Number

 Aircraft Manufacturer

 Registration \ Tail Number

 Engine Manufacturer

 Engine Model

 Number f Engines

 Aircraft Noise Class (Stage)

 Equipment Category

 Equipment Type (LAR Code)

 Equipment Type (IOAG Code)

 Aircraft Equipment Model

 Operator Category

 Operator Name

 Operator I ATA Code

 Operator ICAO Code

 Wing Span (meters)2 C

- 44 CAEP/8

- WP/80

Appendix C to the Report on Agenda Item 2

 Wing Area (square meters)

 Overall Length (meters)

 Belly Volume (cubic meters)

 Fuel Capacity

 Maximum Takeoff Weight (kilograms)

 Maximum Payload (kilograms)

 Maximum Landing Weight (kilograms)

 Range with Maximum Fuel (kilometres)

 Range with Maximum Payload (kilometres)

Useful data fields in the ASQP Database:

 IATA carrier code

 Flight number

 Depart airport

 Arrival airport

 Date of operation

 Day of week

 IOAG depart time

 Actual depart time

 IOAG arrival time

 CRS arri val time

 Actual arrival time

 Wheels off time

 Wheels on time

 Aircraft Tail number

 Taxi out time

 Taxi in time

Useful data fields in the JP Airline Fleets Database:

 Operator Name

 Operator IATA Code

 Operator ICAO Code

 Aircraft Tail number

 Aircraft type an d subtype

 Month and year of manufacturing

 Construction number

 Previous identity

 Number of engines

 manufacturer of engines

 exact type of engines

 Maximum Takeoff Weight (kilograms)

 Seat configuration (or other use than for passenger services)CAEP/8

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Appendix C to the Report on Agenda Item 2 2 C

- 45

APPENDIX

LIS T OF REFERENCES

FAA, 1995, Technical Data to Support FAA Advisory Circular on Reducing Emissions from Commercial Aviation, http://www.epa.gov/otaq/regs/nonroad/aviation/m eta

- faa.txt

. IPCC, 1999, Aviation and the Global Atmosphere, Intergovernmental Panel on Climate Change, Cambridge University Press, ISBN 0 521 66404 7.

B. Kärcher et al., Particles and cirrus clouds (PAZI)

- Overview of results 2000

- 2003. In:

Proceed. Eu ropean Workshop Aviation, Aerosols and Climate, R. Sausen and G.T. Amanatidis (Eds.), Air Pollution Research Report No. 83, Commission of the European Communities, 197

- 206, 2004.

Hagen, D.E., P.D. Whitefield and H. Schlager (1996) Particle emissions in the exhaust plume from commercial jet aircraft under cruise conditions, J. Geophys. Res.

, 101 , 19,551

- 19,557.

B. Kärcher et al., Particles and cirrus clouds (PAZI)

- Overview of results 2000

- 2003. I n: Proceed. European Workshop Aviation, Aerosols and Climate, R. Sausen and G.T. Amanatidis (Eds.), Air Pollution Research Report No. 83, Commission of the European Communities, 197

- 206, 2004.

Coor dinating Research Council, Inc., Handbook of Aviation Fuel Properties, Third Edition CRC Report No. 635, Alpharetta, GA, USA, 2004.

Hagen, D.E., P.D. Whitefield and H. Schlager (1996) Particle emissions in the exhaust plume from commercial jet aircraft und er cruise conditions, J. Geophys. Res.

, 101 , 19,551

- 19,557.

NRC, 1988, Research Priorities for Airborne Particulate Matter: I. Immediate Priorities and a Long

- Range Research Portfolio, Committee on Research Priorities for Airborne Particulate Matter, Nati onal Research Council, http://www.nap.edu/catalog/6131.html

. NRC, 2004, Research Priorities for Airborne Particulate Matter: IV. Continuing Research Progress, Committee on Research Priorities for Airbor ne Particulate Matter, National Research Council, http://www.nap.edu/catalog/10957.html

. EPA, 2004, Particulate Matter Research Program, five years of progress, http://www.epa.gov/pmresearch/pm_research_accomplishments/pdf/pm_research_program_five_ years_of_progress.pdf

NARSTO, 2004, NARSTO (2004) Particulate Matter Assessment for Policy Makers: A NARSTO Assessment. P. McMurry, M. Shepherd, and J. Vickery, eds. Cambridge University Press, Cambridge, England. ISBN 0 52 184287 5.

Petzold, A. and F.P. Schröder (1998) Jet engine exhaust aerosol characterization, Aerosol Sci.
Technol., 28 , 62

- 76.

Petzold, A., R. Busen, F.P. Schröder, R. Baumann, M. Kuhn, J. Ström, D.E. Hagen, P.D. Whitefield, D. Baumgardner, F. Arnold, S. Borrmann, and U. Schumann (1997) Near field measurements on contrail properties from fuels with different sulfur cont ent, J. Geophys. Res.,

102 , 29,867

- 29,880.

Petzold, A., A. Döpelheuer, C.A. Brock, and F.P. Schröder (1999) In situ observations and model calculations of black carbon emission by aircraft at cruise altitude, J. Geophys. Res.

, 104 , 22171

- 22181.2 C

- 46 CAEP/8

- WP/80

Appendix C to the Report on Agenda Item 2

Petzold, A. and F.P. Schröder (1998) Jet engine exhaust aerosol characterization, Aerosol Sci.
Technol., 28 , 62

- 76.

Petzold, A., R. Busen, F.P. Schröder, R. Baumann, M. Kuhn, J. Ström, D.E. Hagen, P.D. Whitefield, D. Baumgardner, F. Arnold, S. Borrmann, and U. Schuma nn (1997) Near field measurements on contrail properties from fuels with different sulfur content, J. Geophys. Res.,

102 , 29,867

- 29,880.

Petzold, A., A. Döpelheuer, C.A. Brock, and F.P. Schröder (1999) In situ observations and model

calculations of black c arbon emission by aircraft at cruise altitude, J. Geophys. Res.

, 104 , 22171

- 22181.

Petzold A et al, Particle emissions from aircraft engines

– a survey of the European project PartEmis, Meterologische Zeitschrift, Vol. 14, No. 4, 465

- 476 (August 2005).

SAE AIR5715, Procedure for the Calculation of Aircraft Emissions

, http://www.sae.org/technical/standards/AIR5715 , (July 2009).

Schumann U., J. Ström, R. Busen, R. Baumann, K. Gierens, M. Krautstru nk, F.P. Schröder and J. Stingl (1996) In situ observations of particles in jet aircraft exhausts and contrails for different

sulfur

- containing fuels, J. Geophys. Res.

, 101 , 6853

- 6869.

Schumann, U., F. Arnold, R. Busen, J. Curtius, B. Kärcher, A. Kiendler, A. Petzold, H. Schlager, F. Schröder, and K.H. Wohlfrom (2002) Influence of fuels sulfur on the composition of aircraft exhaust plumes: The experiments SULFUR 1

- 7, J. Geophys. Res.

, 107 (10.1029/2001JD000813),

AAC 2

- 1

– AAC 2

- 27.

Whitefield, P.D., D. Hage n, J. Wormhoudt, R.C. Miake

- Lye, C. Wilson, K. Brundish, I.A. Waitz, S. Lukachko, and C.K. Yam, 2002: NASA/QinetiQ Collaborative Program

– Final Report, NASA

TM

- 2002

- 211900 and ARL

- CR

- 0508, NASA, Washington, DC, USA, 193 pp.

EXAMPLES OF MODELLING SYSTEMS

The following list contains examples of modelling systems for airport local air quality studies. This list is neither complete nor prescriptive.

Name and Version Availability Website

ADMS Application, publicly available www.cerc.co.uk

ALAQS

- AV Experimental, available to Eurocontrol member states and other users by special agreement. www.eurocontrol.int

AEDT

- EDMS 5.1 Application, publicly available www.faa.gov

LASPORT 2.0 Application, publicly available www.janicke.deCAEP/8

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Appendix C to the Report on Agenda Item 2 2 C

- 47

Chapter 2 Emissions Inventory

Annex 1

Aircraft Emissions Appendix D

First Order Approximation v3.0 Method
for Estimating PM Em issions from Aircraft Engines2 C

- 48 CAEP/8

- WP/80

Appendix C to the Report on Agenda Item 2

FIRST ORDER APPROXIMATION V3.0 (FOA3.0) for ESTIMATING PARTICULATE MATTER (PM) EMISSIONS from AIRCRAFT ENGINES

Nomenclature

AFR Air

- to

- Fuel Ratio (mass basis).

BPR By

- Pass Ratio.

CI Carbon Index. A measure of the b lack carbon mass per

standard volume of flow. The volume is in standard cubic meters Standard atmosphere is defined as the volume occupied at 273.15 degrees Kelvin and 1 atmosphere of absolute pressure). (mg/m3 produced by burning 1 kg fuel).

EI Emis sion Index. A pollutant emission rate based on one

kilogram of fuel burned. The units of an EI are normally given as g/kg fuel. However, for convenience the units of mg/kg of fuel are used in this document unless explicitly stated

otherwise.

EI HC Emi ssion index for total hydrocarbons as listed in the ICAO

Data Bank. (g/kg fuel)

EI HCCFM56 Emission index for total hydrocarbons for the CFM56

- 2

- C5

engine as listed in the ICAO Data Bank (g/kg fuel).

EI PMvol

- orgCFM56 Emission index for CFM56

- 2

- C1 engine a s derived in the

APEX1 measurements. (mg/kg fuel)

EI HCEngine Emission index for total hydrocarbons from the ICAO Data

Bank for the subject engine. (g/kg fuel)

EI PMnvols Emission Index for non

- volatile particulate matter primarily

consisting of black carbon. (mg/kg fuel)

EI PMtotal Total particulate matter emission index for both volatile and

non

- volatile components. (mg/kg fuel)

EI PMvol

– FSC Emission Index for volatile sulphate particulate matter due to

fuel sulphur. (mg/kg fuel)

EI PMvol

- FuelOr ganics Emission index for organic volatile particulate matter primarily

due to incomplete combustion of fuel. (mg/kg fuel)

HC Total hydrocarbons.

ICAO International Civil Aviation Organization.

FOA First Order Approximation. FOA3.0 is the latest ver sion of the

methodology to provide emission indexes for particulate matter

emitted from aircraft listed in the ICAO Data Bank.

FSC Fuel sulphur content. (mass fraction)

LTO ICAO Landing Take

- Off cycle.

MW out Molecular weight of SO 4 - 2 (S VI = 96 ).

MW Sulphur Molecular weight of elemental sulfur (S IV = 32).

PM Particulate Matter. Q

core Exhaust volumetric flow rate as related to fuel burn (m 3 /kg

fuel). Q Mixed Exhaust volumetric flow rate including that due to fuel burn

and the bypass air (m 3 /kg fuel).

SF Scaling factor.CAEP/8

- WP/80

Appendix C to the Report on Agenda Item 2 2 C

- 49

SN Smoke Number. The methodology in this document based on

smoke numbers as defined in Appendix 2 in the ICAO Annex

16 document.

SN mode Smoke number for one of the ICAO defined modes (take

- off,

climb

- out, approac h, or idle).

SN

max Maximum smoke number.

STP Standard temperature and pressure. As used in this

document is 273.15 degrees Kelvin and 1 atmosphere of absolute pressure.

ε Fuel sulphur conversion efficiency (mass fraction).

δ Ratio of as derived for use in Equation 9.

(mg/kg)

1. Introduction

FOA3.0 is a method for estimating the particulate emissions both non

- volatile (soot) and volatile

in the form of Emission Indices (EIs) as mass emitted per kilogram of fuel. 1,2 Currently there are three components to the estimation process and each must be calculated separately, with the total EI being the sum of the parts. The basic technique for each c omponent of Particulate Matter (PM)

is as follows.

1.1 Non

- volatile PM (EI PMnvols )

The calculation of non

- volatile PM is based on the engine‘s Smoke Number (SN), Air Fuel Ratio (AFR) and if applicable its by

- pass ratio (BPR). The essence of the technique is to convert the SN via an experimental correlation into a Carbon Index (CI). The CI is the mass of non

- volatile PM per unit volume of exhaust. Using the engine AFR and BPR the volume of the exhaust (Q) per kilogram of fuel is calculated thence the produ ct CI and Q gives the EI with the unit of mass per kilogram of fuel burn. Units as reported in this work are mg/kg of fuel unless otherwise stated. The EI must be computed for the various power settings used in the vicinity of airports for

EI PMnvols

.

1. 2 Volatile Sulphate PM (EI PMvol

– FSC )

Volatile sulphate PM is formed from the fuel sulphur via oxidation of SO 2 (S IV ) to SO 3 (S VI ) and subsequent hydration, in the exhaust plume, of the SO 3 to H 2 SO 4 . The EI is calculated from the fuel sulphur content and the conversion rate of S IV to S VI (ε). As such, the EI is does not vary by power setting.

1.3 Volatile Organic PM ( EI PMvol

- FuelOrganics )

Measurements of condensable organics in the engine exhaust are very limited. Based on the assumption that condensable organics are directly related t o unburned hydrocarbons, an estimate is made by scaling the engine‘s reported ICAO (International Civil Aviation Administration) Hydrocarbon (HC) EI to those of other engines in the database. Making a second assumption that modern engines behave in a simi lar manner, the HC ratio can be multiplied by the volatile2 C

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Appendix C to the Report on Agenda Item 2

organic PM EI for the CFM56

- 2

- C1 engine which was measured during NASA‘s Aircraft Particle Emissions Experiment 1 (APEX1). 3 The result is an EI that is both engine and power setting specific for t he volatile organic PM.

1.4 PM from Engine Lubricant

Data are not available to allow prediction of this EI for PM. It is currently assumed, based upon measurement results from APEX1, that the present EI volatile organic PM includes a contribution

due to lubrication oil.

2. Data Sources

2.1 ICAO Engine Emissions Data Bank

Values of SN, EI HC and BPR for engines can be found in the ICAO Data Bank for the four power settings of the Landing Take

- off cycle (LTO). Unfortunately there are gaps in the data ba nk for SN and BPR values. This problem is being addressed by ICAO‘s Committee on Aviation

Environmental Protection as follows:

 Addition of new engine data by late 2008.

 Clarification for mixed turbofans as to whether the measurements were made on the engi ne core or over both the core and by

- pass flows by late 2008.

 Addition of missing SN data by late 2008.

Since the SN data within the ICAO emissions data bank is fragmentary for many engines, some only showing the maximum SN, general guidelines have been d eveloped to help fill

- in the data gaps. These guidelines apply when instead of a listed value the symbol ―

- ― or ―NA‖ appears which denotes that either the SN was not derived at that particular power setting or it was not reported since only the maximum is required. These guidelines were developed by Calvert 4 and are based on analyzing modal trends within groups of engines to derive scaling factors that can be used to predict the missing data. A scaling factor is a ratio of a modal SN to the maximum SN for an engine:

(1)

where SF = Scaling Factor

SN mode = SN for one of the modes (take

- off, climb

- out, approach, or idle)

SN

max = Maximum SN

In order to reduce the uncertainties in developing the SF values, SNs with values less than 6 were excluded from the analysis. The resulting SF values are presented in Table 1. The majority of engines are covered by the category non DAC (Double Annular Combustor) engines, however, Aviadgatel, General Electric CF34, Textron Lycoming and DAC engine s have significantly

different SF vales from the norm.CAEP/8

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Engine Category Takeoff Climb

- out Approach Idle

Most non

- DAC engines 1.0 0.9 0.3 0.3

Aviadgatel engines 1.0 1.0 0.8 0.3

GE CF34 engines 1.0 0.4 0.3 0.3

Textron Lycoming engines 1.0 1.0 0.6 0.3

GE and CFM DAC engines 0.3 0.3 0.3 1.0

Table 1. Suggested SF Values to Predict Missing SNs within the ICAO Emissions

Databank.

Using these SF values and Equation 1, missing SN data can be reasonably filled

- in if at least one

of the modal SN values for a n engine is known.

It is also important to note that in addition to the missing SNs in the ICAO Data Bank, other concerns also exist. If a SN is listed as zero (0) by the manufacturers no attempt has been made to change the value. In these cases, non

- vo latile PM estimates will be also be zero which is unrealistic but it was considered to be undesirable by the group to change any listed values. In some cases the SN for the idle power setting is listed with an asterisk (*) as a superscript. This

indicate s that the SN has been calculated at a power setting other than 7%. Finally, if the value is preceded by the symbol ―<‖ the provided value should still be used.

To assist in on

- going analysis, a separate table has been included in spreadsheet form (Calve rt

method

- Databank

- Issue_15

- C.xls) as the interim recommended values. Manufacturers are working to include all SNs for engines still in production in the ICAO Data Bank and those values will replace those included in the table.

2.2 Air

- Fuel

- Ratio (AFR)

AFR is not included in the ICAO Data Bank. This problem has been overcome by the use of average fleet AFRs. These generic values were agreed with representatives of the three main engine manufacturers and are shown in Table 2.

Power Setting AFR 7% (id le) 106 30% (approach) 83 85% (climb

- out) 51 100% (take

- off) 45

Table 2. Representative Air

- Fuel

- Ratios Listed by ICAO Power Settings (Mode)2 C

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Appendix C to the Report on Agenda Item 2

2.3 Non

- Volatile PM (EI PMnvols )

The calculation of EI PMnvols is accomplished by first computing the CI, whi ch is based on a statistical correlation with the ICAO SN being the independent variable. Derivation of the appropriate SN when the value is not available in the ICAO Data Bank was described in Section

2.1. Also of note is that the statistical correlatio n equation that must be used has two forms depending on the value of the SN. The dividing line is a SN value of less than or equal to 30 or

above 30.

The independent variable for the derivation of the flow rate is the AFR which was listed for each

pow er setting (mode) in Section 2.2. Of note is that two possible choices exist for the appropriate flow rate to use. This is due to SNs being listed either by core flow or mixed flow in the ICAO Data Bank. The listing in the ICAO Data Bank for Engine Type (TF or MTF) allows the choice to be easily made. However, the Data Bank is undergoing changes and the user should be careful

in their choice.

The CI must then be multiplied by the appropriate flow rate to determine EI PMnvols

.

2.4 Volatile Sulphate PM (EI PMvol

– FSC )

Fuel sulphur contents (FSC) can vary widely between different batches of aviation fuel and are not included in the ICAO Data Bank. For application to the FOA airport, this input has been left as a variable to allow the most applicable valu e, such as the national and/or international mean sulphur contents, should be used. As a guide, typical FSC values rang from 0.005 to 0.068 weight percent 5 with a global average of 0.03 weight percent 6 . Using a conservative value of 0.068 weight percent i s currently recommended in the absence of more specific FSC data.

There is uncertainty about the S IV to S VI conversion process, the non

- linear production of S VI that varies with changing FSC and engine operating conditions. The variable for fuel sulphur

c onversion efficiency ( ε) may be input directly by the practitioner if detailed information is known. However, the value is often unknown and a default value is recommended in these

situations. Based on the most recent measurements from APEX and PARTEMIS 7 , the range of

the sul phur conversion efficiency can range from 0.5 to over 3.5 wt%. A median value of 2.4 wt%, based on the APEX measurements, is recommended as the default value. The value of the fuel sulphur conversion efficiency is still a topic of ongoing research and fu ture refinements are expected.

2.5 Volatile Organic Aerosol ( EI vol

- FuelOrganics )

Organic Volatile PM is calculated from the engine ratio of EI HC reported in the ICAO databank with the denominator being the EI HC for the CFM56

- 2

- C5 engine which is the clos est value to the engine measured during APEX1 3 . This ratio is multiplied by the measured volatile organic PM

EI from APEX1 for the CFM56

- 2

- C1 engine. The measured values are shown in Table 3.CAEP/8

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LTO Mode EI PMVol

- orgCFM56

(mg/kg fuel)

Take

- off 4.6

Climb

- out 3.8 Approach 4.5

Idle 11.3

Table 3. Measured Volatile EI from Reference 1 Used to Calculate Organic Volatile PM.

3. PM EI Calculation

3.1 Non

- volatile PM (EI PMnvols )

The CI at STP for SN ≤ 30 is calculated from Equation 2 8

.

(2)

For SN > 30 Equation 3 should be used.

(3)

The exhaust volumetric flow rate at STP for the engine core is:

(4)

Where AFR is the mode specific value from Table 2.

It should be noted that the constants in this equation have the units of m 3 /kg of fuel. Similarly, constants used for other equations listed in this document will have units.

And for a mi xed (core and by

- pass) flow:

(5)

(6)

3.2 Volatile Sulphate PM (EI PMvol

– FSC )

The EI for sulphate PM is calculated from:

(7)2 C

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Appendix C to the Report on Agenda Item 2

Where MW out = 96 (SO 4 - 2 ) and MW Sulphur = 32. Th e values of FSC and ε are user defined with default values as previously defined.

3.3 Volatile Organic PM (EI PMvol

– Fuel Organics )

The EI of the volatile organic PM is calculated from:

(8)

Where EI HCCFM56 is the ICAO total hydr ocarbon emission index for the CFM56

- 2

- C1 engine.

EI PMvol

- orgCFM56 is the APEX1 measured volatile organics EI from Table 3, and. EI HCEngine is the

EI HC from the ICAO Data Bank for the subject engine (engine where the EI is being determined).

Of note is: 1) the units of EI HCEngine and EI HCCFM56 are g/kg fuel as listed in the ICAO Data Bank and cancel; and, 2) that the ratio of EI PMvol

- orgCFM56 and EI HCCFM56 is a constant for each mode. Since only the modal value of the EI HC for the subject engine changes, a simplification can be made to Equation 8 which is easier to calculate. This results in:

(9)

Where δ is constant ratio by mode. Values of this constant are given in Table 4 for each mode.

LTO Mode δ (mg/g)

Take

- off 115

C limb

- out 76 Approach 56.25

Idle 6.17

Table 4. Modal Values for the Ratio of EI PMVol

- orgCFM56 and EI HCCFM56 in Equation 8

4. Example Calculations

This example is based on calculating PM EIs for the JT8D

- 217 series engines with an ICAO UID

of 1PW018. Derived values are presented for all modes while complete calculations are only shown for the idle since the process is simply repeated for the other modes using appropriate variables. Of course the PM for sulphur does not change by power setting and is t he same for all modes. HC EI and SN data for the idle mode from the ICAO Emission Data Bank for this engine

is shown in Table 5.CAEP/8

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LTO Mode EI HC (g/kg) SN

Takeoff 0.28 13.2

Climb 0.43 Missing Approach 1.6 Missing

Idle 3.33 Missing

Maximum Value NA 13 .3

Table 5. ICAO Data for the JT8D

- 217 Series Engine, Idle Mode.

To fill

- in the missing SN value for the idle mode, a scaling factor of 0.3 from Table 1 corresponding to ―most non

- DAC engines‖ and the idle mode is used:

To cal culate non

- volatile PM EI (EI PMnvols ) as function of SN, since the SN< 30, Equation 2 is

used.

Based on the ICAO Data Bank, the mixed exhaust volumetric flow rate should be used with a bypass ratio of 1.73. Using the idle AFR of 106 (Table 2), the exhaust volumetric flow rate is calculated, via Equation 5, as follows:

Hence:

or 0.086 g/kg

Assuming a fuel sulfur content of 0.068 wt% (fraction 0.00068) and a S IV to S VI conversion r ate of 2.4 wt% (fraction 0.024), the modal independent EI PMvol

- FSC is calculated as follows:

or 0.049 g/kg

The EI PMvol

– Fuel Organics may be calculated using the values in Table3, Table 5, and the EI HC for the specific engine as listed in the ICAO Data Bank corresponding to the idle mode:

or 0.021 g/kg

Alternatively, the values in Table 5 may be multiplied by the EI HC for the specific engine as listed

in the ICAO Data Bank as:2 C

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Appendix C to the Report on Agenda Item 2

I n summary, the example calculation results of applying FOA3 to the idle mode for the JT8D

- 217 series engine are:

The total EI for all components of PM emissions is then:

EI PMtotal = 86.3 + 49.0 + 20.6 = 155.9 mg / kg of fuel or 0.156 g/kg of fuel burn.

While the EI for sulphur does not change by power setting, the other EIs must be calculated for

each mode. Table 6 shows the results for all modes. Of note is that the maximum sm oke number

was used for the non

- volatile PM EI estimates.

ICAO Defined Power Setting (mode) EI PMn

- vols EI PMvols

- FSC EI PMvol

FuelOrganics Total PM EI

by Mode

Idle 86.3 49.0 20.6 155.9 Approach 67.6 49.0 90.0 206.6

Climb

- out 161.7 49.0 32.7 243.4

Ta keoff 161.2 49.0 32.2 242.4

Table 6. Values of EIPM for the JT8D

- 217 Series Engine (mg/kg fuel)

5. Uncertainties

As its title suggests FOA3.0 is an approximation. The PM ad hoc group of CAEP Working Group 3 has endeavoured to make the methodology a s accurate as possible. However, the user should be aware that not all physical concepts are well understood and data for many of the parameters are sparse. This leads to uncertainties in the estimation methodology including:

 Lack of data in the ICAO Data Bank, particularly:

o SN.

o Detail of whether the by

- pass flow was included in the SN measurement.

 Reliance on average values of the specific engine‘s:

o AFR.

o Fuel sulphur content.

o S IV to S VI conversion factor.CAEP/8

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o Combustor technology.

 Extremely limited data on volatile organics.

 No information on the effect of engine lubricants.

 Inaccuracies and measurement differences in reported data:

o Annex 16 states that measured SNs can vary by ± 3.

o Reported mass measurements vary considerably resulting in ranges of v alues.

The limitations of the Data Bank are being addressed by the engine manufacturers through CEAP WG3. Values of engine AFR are unlikely to be available as they are commercially sensitive.

More confidence in the S IV to S VI conversion factor, volatile o rganics and the effect of engine lubricant will come with more experimental measurements and improved measurement techniques.

Since the inception of the FOA process, and it development into FOA3.0, the methodology has

continued to evolve and the estimate accuracy improved. The FOA process is not static and will continue to evolve until measurements are sufficient that the approximation is no longer needed. In the interim, CAEP and specifically the ad hoc PM working group will continue to review

available information to improve the methodology and the input parameters to the degree possible.

6. References

1. CAEP, "Particulate Matter Charactisation", Information Paper No. 6, Working Group 3

- Technical Emissions, ICAO Committee for Aviation Environmental Protection (CAEP) meeting, February 2007.

2. ICAO, "Airport Air Quality Guidance Manual," Document 9889, ICAO PRELINIMARY

UNEDITED VERSION

- 15 April 2007.

3. NASA. Aircraft Particle Emissions Experiment (APEX). C.C. Wey, U.S. Army Research Laboratory, Glenn Research Center, Cleveland, Ohio. ARL

– TR

– 3903. 2006

- 214382, September

2006.

4. Calvert, J.W. ―Revisions to Smoke Number Data in Emissions Databank.‖ Gas Turbine Technologies, QinetiQ. February 23, 2006.

5. Coordinating Research Council, Inc., Hand book of Aviation Fuel Properties, Third Edition CRC Report No. 635, Alpharetta, GA, USA, 2004.

6. IPCC, 1999, Aviation and the Global Atmosphere, Intergovernmental Panel on Climate Change, Cambridge University Press, ISBN 0 521 66404 7.2 C

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Appendix C to the Report on Agenda Item 2

7. Katragkoue, E ., S. Wilhelm, F. Arnold, C. Wilson, First gaseous Sulfur (VI) measurements in the simulated internal flow of an aircraft gas turbine engine during project PartEmis, ISSN 0094

- 8276, Geophysical research letters, November, 2003

.

8. S. P. Girling, C. D. Hur ley, J. P. Mitchell and A. L. Nichols, Development and

Characterization of a Smoke Generator for the Calibration of Aerosol Emissions from Gas Turbine Engines, Aerosol Science and Technology, 13:8

- 19, 1990.

— — — — — — — —2 C

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Appendix C to the Report on Agenda Item 2

Chapter 4

DISPERSION MODELING

Content

1. Introduction 2. External Requirements and Drivers 3. General Dispersion Concepts 4. Required Model Inputs 5. Dispersion Calculation 6. Model Outputs 7. Modeling Application and Interpretation of Results

8. References

Annex 4A. Overview of Dispersion Modeling Methodologies Annex 4B. Commonly Used Dispersion Models in the Vicinity of Airports Annex 4C. Climatological Information Sources

1

. INTRODUCTION

In the emission inventory chapter, guidance on estimating the mass emitted for variou s pollutants was discussed. However, the total mass emitted does not account for mixing in the atmosphere which determines local concentrations or how much mass is mixed in the air at any given time. Additional modeling is required to estimate these loca l ambient

concentrations.

A trace substance that has been released from a source into the free atmosphere will be transported by the mean wind field and dispersed by atmospheric turbulence. This process is referred to as atmospheric dispersion. Dispers ion can be more rigidly defined 1 as ― the scattering of the values of a frequency distribution from an average.‖ It then follows that atmospheric dispersion modeling is the mathematical simulation of the scattering or mixing process in the ambient atmosphere

. The trace substances most often evaluated are regulated atmospheric pollut ants and were delineated in the emission chapter for airport sources. In an airport

- related dispersion calculation, the atmospheric mixing of these trace substances or pollutants that are emitted from local sources is modelled based on scientific princip als and the resulting concentration distributions (usually near the ground) are predicted. The results, or predicted atmospheric concentrations, form the basis for local air quality (LAQ) impact studies and are used to show compliance with required regulat ions and/or standards.

This chapter presents the needs for dispersion modeling in the vicinity of airports, provides a brief overview of dispersion models, summarizes typical practices that occur during atmospheric dispersion modeling at airports, and exa mines how predicted concentrations are used to estimate impacts . The chapter has been laid out to follow the procedure established in the emission chapter. That is, the required modeling will be discussed in a simple, advanced, and sophisticated approach

.

2

. EXTERNAL REQUIREMENT S AND DRIVERS2 C

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This section discusses the need for Dispersion Modeling and the external drivers that both cause and affect this need. As described in detail in Chapter 1: Regulatory Frameworks and Drivers, air quality assessments for proposed actions at airports are often necessary to comply

with:

 Worsening air quality leading to reduced margins against existing regulations;

 Increased awareness of health impacts, leading to the production of new regulations, including the addition of new pollutant species;

 Development constraints resulting from limitations imposed by the need to meet air quality standards;

 Increasing public expectation regarding air quality levels;

 Public relations exercises carried out by airport and environmental lobbies; and,

 Legislative requirements of the various countries and regions.

Emission modeling to meet these requirements has been previously discussed. Emission modeling, a prerequisite to dispersion modeling, allows the change in emissions to be

revie wed temporally and spatially. However, direct impacts are more related to the ambient concentrations and not just the mass of emissions emitted. Ambient air quality standards, evaluation of real impacts, and health impacts are better evaluated by the use of ambient concentrations than with mass emitted. As previously described, atmospheric mixing of emissions results in ambient concentrations most often used to determine local impacts. Measurements, described in Chapter 5 of this guidance, can be very c ostly, only define the concentration at a point in space for each measurement, and do not readily reveal the fractional contribution from each contributing source. Dispersion modeling allows the evaluation of local air quality to be done at a reasonable c ost. Regardless, the need for dispersion modeling is to determine the ambient mixing as a part of the overall analysis

process.

Beyond the evident need for dispersion modeling, ordinances or legislation often mandates the estimation process be used. The regulations resulting from these legal requirements may also specify how the dispersion modeling must be accomplished or how variables are considered. The analyst is prompted to review any related requirements to insure the process

occurs as mandated.

3

. GE NERAL DISPERSION CON CEPTS

This section provides a brief overview of the basic physical concepts included in dispersion modeling and the process required. References are included to allow interested parties to go deeper in exploring these concepts than p resented here. The understanding of how the models work should lead to more appropriate use of the models.

When a trace element or pollutant is emitted from a source, the final fate is determined by the characteristics of the pollutant, source characte ristics, atmospheric motion, and local topography. Each of these parameters plays an important role in the local concentrations. A pollutant that is released in its final form is called a primary pollutant. Primary pollutants that are very slow to react with other gases in the atmosphere are called passive pollutants. Primary pollutants such as carbon monoxide (CO) are often called inert because of the very long reaction time and residence time in the atmosphere. Secondary pollutants are formed

in the atmosphere when the original precursor emitted undergoes chemical reactions or otherCAEP/8

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- 61

conversion processes in the atmosphere and forms a new pollutant. The pollutant is termed secondary since the final composition is not as released from the source. Ozone (O 3 ) is a secondary pollutant.

The pollutant source affects the local concentrations due to the location of the release, the total mass flow rate, and the dynamics of the exhaust air due to the effect on the atmospheric dispersion in addition to the at mospheric motion. Atmospheric motions determine the overall direction the emissions travel and are primarily responsible for the mixing with the ambient atmosphere ( dispersion ), thereby creating a pollutant  ̳plume‘ (or  ̳puff‘). The direction of the plume is determined by the large scale motion such as the mean wind flow while mixing

is more related to small scale eddies in the flow referred to as turbulence . Likewise terrain characteristics and local building structures will have an effect on local area concentrations due to changes in the wind patterns and the generation of turbulence. All of these parameters affect atmospheric dispersion and lead to a three

- dimensional, generally time

- dependent

concentration distribution of the emitted trace substance (pollutant). Likewise other

substance

- specific processes may have an effect such as dry and wet deposition.

The quantities that determine atmospheric dispersion resulting in a local concentration can be grouped as follows:

 Q1 Source parameters (locati on, shape, dynamics of the exhaust air);

 Q2 Emission parameters (emission strength of each trace substance for each source);

 Q3 Substance parameters (e.g. conversion or deposition properties);

 Q4 Atmospheric parameters (e.g. wind speed, wind direction, tur bulence properties, and temperature); and,

 Q5 Terrain parameters (e.g. surface roughness, terrain profile, obstacles).

Not all of the above parameters are independent and most of the parameters are time

dependent. It is evident that the parameter set inc ludes additional information than was required for emission calculations, even when emission allocation has been conducted as described in Chapter 3.

At airports, the relevant sources can be grouped as follows:

 S1 Aircraft, including Auxiliary Power Unit s (APUs);

 S2 Aircraft Handling Sources (e.g. Ground Support Equipment (GSE), aircraft fueling, airside vehicles);

 S3 Stationary and area sources (e.g. power plants, fire training); and,

 S4 Airport access traffic (e.g. landside motor vehicles).

The disper sion methodologies used are of course only for those sources directly included in the model. Regional or background contributions also add to the total local concentration to produce the total concentration. The total concentration is needed to compare t o the applicable criteria or standards. These background sources can be substantial and come from sources at varying distances from the airport. How background sources and the resulting

concentrations are accounted for needs to be considered based on the spatial resolution of the modeling area and data sources to be used such as long

- term ambient monitoring stations. This stands in contrast to noise assessments, where the airport contribution is usually by far the dominating component. To account for th e overall concentration the background concentration must be added to the concentration predicted by the models. This results in:2 C

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Appendix C to the Report on Agenda Item 2

[4.1]

Where: c = concentration with the subscripts t, s and b representing total, source, and background, respect ively.

The summation in Equation 4.1 represents the concentration at a point in space from all sources and is the value that is compared to applicable ambient air quality standards. Of note is that concentration, c, is pollutant specific. That is, pollu tants of different species cannot be

added.

Figure 4.1 shows an a) an overview of the modeling process and b) the detailed steps required.

a

. Process Overview

b. Detailed Breakdown of Atmospheric Concentration Due to S1

– S4

Figure 4.1. Inputs and Outputs of Dispersion Modeling. 2

Several approaches to dispersion modeling have been applied at various airports around the world to predict local concentrations. As the science continues to evolve, so will the airport

models. As such, this chapter will concentrate on the common methodologies currently used rather than on specific models.

The actual formulation for these models may vary. To assist the reader in a more comprehensive understanding of dispersion model methodologi es, model formulations are briefly discussed in Annex A. Computer models in commons use for airport dispersion modelling are listed in Annex B.

S1

- S4

Q1+Q2 Q4 Q5

Q3 Dispersion

Model Receptors

Atmospheric Concentration at

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4

. REQUIRED MODEL INPUT S

This section provides information on variables needed to perform a dispersion analys is. While this is a general overview to provide understanding for the reader, variables required will vary by modeling effort (simple, advanced, sophisticated) and the specific model used. Additionally, each airport is unique and this large variability, the differences in the availability of data, and the desired final product also result in different data sets for each airport.

4.1 Emission Source Information

A brief overview of the information that will be needed to complete the concentrations analy sis is included in this section.

4.1.1 Airport Emission Sources

Air pollution sources at airports are many and varied. In order to perform concentration modeling, for each source studied, the emission strength for each of the modelled substance

must b e available. A detailed description on the emission sources found at an airport is given in Chapter 2 of this guidance manual.

4.1.2 Airport Temporal and Spatial Considerations (e.g., taxiways, runways, gates)

When performing an emission inventory, spat ial and temporal allocations are not always required or completed. However, spatial and temporal allocations are of prime importance during dispersion modeling since local concentrations will be calculated. These local concentrations depend upon the dist ance to a source and its time of operation. This requires not only the emission data, but explicit detail on when and where and in which way the emissions occur. Airport spatial and temporal variation was previously discussed during

emission allocation i n Chapter 3.

Dispersion modeling often relies on Cartesian coordinates (x,y,z) where x and y are the horizontal distances and z is the vertical distance from an established datum point. A common practice, for easy transfer to maps, is to set the positi ve y axis is in the north direction. A thorough understanding of the airport operation is required for detailed dispersion modeling (see Chapter 3). For all but the simple approach, all source locations must be established (see Chapter 3) and for dispers ion modeling, a new component, the receptor must be added as discussed in Section 4.4. The receptor location must be exactly specified, as with the source, leading to the use of coordinates such as the Cartesian coordinate system. The defined receptor lo cation determines where the concentration will be predicted using the dispersion models. This is most often at locations of frequent human use. Some dispersion models are based on specific time periods since their dispersion parameters change with time a fter release. This is often an internal parameter, transparent to the user, and can be adapted based on the output needs to compare to ambient air quality standards.

4.1.3 Emission Factors

Emission factors are needed to determine the rate of release for emissions from each source. Emission factors are both source and pollutant specific. The reader is referred to Chapter 2 for a complete discussion of emission factors.2 C

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4.2 Meteorology

Meteorology is an essential input for the dispersion calculat ion. Without an input for the local weather, it is not possible to perform dispersion modeling except in the simple cases. For all modeling of any sophistication, the parameters for the planetary boundary layer (PBL) must

be known. As with other variable s, the degree of sophistication of the modeling process can vary but a general listing of needs is discussed here. Additionally, some common sources for

this data are listed in Annex C.

4.2.1 Wind Data

The horizontal wind speed (velocity) and direction generated by the geostrophic wind component and altered by local surface characteristics and other parameters such as terrain is of primary importance in all but the simple case. In the advanced and sophisticated approach, local climatology must be establ ished in more detail and may include wind data from multiple elevations and/or vertical wind gradients. Often this historical data is available from existing records (see Annex C). The wind speed and direction will vary by surface characteristics and

top ography, local buildings, surface cover, and nearby influences such as large bodies of water, to establish a suitable wind field depending on model requirements.

4.2.2 Turbulence and Atmospheric Stability

The atmospheric stability can be simply defined as the turbulent status of the atmosphere and has a significant effect on the dilution rate of pollutants. Turbulence refers to the small motions of the atmosphere, generally circular in nature and referred to as eddies. These eddies vary dramatically in size depending on atmospheric stability. Small eddies can ―rip‖ apart the plume and cause mixing with the local air while large eddies tend to move the entire plume.

Turbulence can be characterized in several ways including empirical methods (e.g., the

P asquill

- Gifford Stability Classes), the flux Richardson number, the gradient Richardson number, or the Monin

- Obukhov length. While each requires different inputs to determine, the basic meteorological information needed is wind speed by height (wind shear ), temperature by height (lapse rate), wind velocity fluctuations, and surface characteristics.

Turbulence is often broken into the categories of stable (vertical mixing of pollutants is hindered), neutral (vertical motion of the atmosphere is nether hinde red or enhanced), and unstable (vertical motion of the atmosphere is enhanced).

4.2.3 Upper Air Data

In the advanced and complex analysis it is recognized that the atmospheric conditions change with height. To account for this change, meteorological data at greater heights (up to some hundred metres) than surface data are often used, although some models can approximate the change with height based on surface data and use boundary layer parameterization. If the measured data are used, these data come fro m acoustic soundings, release of balloons with instrument packages, and reports by aircraft.

4.2.4 Temperature

The ambient temperature has an effect on the rate of chemical reactions and may be needed in the sophisticated approach. The change of temp erature with height (lapse rate) may beCAEP/8

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needed by models to assist in determining atmospheric stability and could be needed for both the advanced and sophisticated approach.

4.2.5 Cloud Cover

Cloud cover has the direct effect of changing the albedo and is often used indirectly for atmospheric stability in the advanced approach.

4.2.6 Derived Parameters (Model Specific)

Many parameters may be important depending upon the model chosen (e.g., sensible heat flux, surface friction velocity, convective veloc ity scale, vertical potential temperature gradient, Monin

- Obukhov length, and the Bowen ratio). Often these parameters can be derived from the basic meteorological data listed above. The parameters are not described here but if not computed directly by t he dispersion model selected, the user should take great care to understand these parameters and how they may be derived.

4.3 Surface Roughness

Different types of surfaces change the frictional characteristics of the surface and affect the

vertical win d profile and the turbulence characteristics. For airports this is often a vegetative flat relief near the runways. But the location and height of buildings such as the terminal, tree lines, and for some airports significant changes in the surface profil e must all be determined. After this determination, charts may be used to determine the value of the surface roughness parameter (z 0 ) to be included in the model. Table 4.1 shows an example of values that can be selected. Of note is that this is a para meter and not a true length of the objects on the surface.

Table 4.1 Surface Roughness Length, z 0, for Typical Surfaces 3

Terrain Description Z 0 (m)

Water 0.0001 Grassland (winter) 0.001 Grassland (summer) 0.1 Cultivated Land (winter) 0.01

Cultivated Land (summer) 0.2 Swamp 0.2

Desert Shrubland 0.3 Deciduous Forest (winter) 0.5 Deciduous Forest (summer) 1.3

Coniferous Forest 1.3

Urban 1.0

– 3.0

4.4 Receptor Information

A receptor is a location in space that may represent human occupation or si mply a location of interest. Receptors can also simply be a predetermined grid of a specific size, centered on an established airport reference point. Airport receptor locations may be defined on or off of the airport. These are chosen by a review of th e airport with particular interest in locations where normal human activity occurs or in other locations for example nature reserves. The choice of receptor locations will result in modelled concentrations at these points used to determine the overall impa ct at that location.2 C

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4.5 Background Concentrations

As previously discussed (Equation 4.1), background concentrations are due to sources not considered during the modeling process. These concentrations must be added on a pollutant specific basis to th e model results to obtain the total concentration of any pollutant. The background concentrations are generated by nearby roadways, industry, commercial operations, residential areas, and long

- range transport. The background concentration is most

often d etermined by long

- term measurement stations in the area since the sources are too numerous to be modelled during an airport evaluation. The averaged upwind concentration to the airport is often used and may be temporally allocated to account for diurnal c hanges in the other local sources. Depending on the pollutant, significant percentages of the overall (measured) concentrations may be from background concentrations sometimes brought into the study area from large distances.

4.6 Atmospheric Chemistry

A s previously mentioned, pollutants may react with other components in the atmosphere after being emitted by the source. This causes a change in precursors and creates new pollutants. This is particularly important for aircraft emissions where secondary g as and particulate matter pollutants are created. This is an advanced topic and will most often be built into the model used or may even be ignored depending upon the scope of the study. Chemical reactions are always ignored in the simple approach define d here. In the case where atmospheric chemistry is not explicitly considered, ratios based on historic data can be applied and this is defined in this document as the advanced approach. For example, the ratio

of NO to NO 2 is important. Historic data may provide a typical ratio. This ratio can then be applied to the NO

x prediction (NO + NO 2 ) which is predicted by models without chemical algorithms. If not performed by the model, speciation of hydrocarbons may also be approximated in this manner based on the total hydrocarbon prediction and historic data.

Chemical reactions proceed at different rates and are affected by ambient concentrations, transport time, and ambient conditions with all being considered in the sophisticated approach. The time for th e reaction to occur is different for each pollutant and the reaction rate is necessary for dispersion modeling of reactive pollutants.

5

. DISPERSION CALCULATI ON

Annex A contains a very general overview of the dispersion methodologies while Annex B

lists mo dels commonly used for airport analysis. The purpose of this section is not to provide detailed directions on the use of these methodologies or concepts and the reader is directed to the appropriate texts or user manuals for the specific methodology/metho d chosen. The fundamental approach for simple, advanced and sophisticated is described in this section. The choice of which method is best suited for the analysis will depend on the data available and

the desired use of the results.

5.1. Analysis and L evel of Effort

As the analyst proceeds from the simple, to the advanced, and to the sophisticated approaches, the data requirements increase as well as the analysis time. However, the accuracy increases with the additional effort required if the input da ta is of good quality. Simple approaches should be conservative in nature while the advanced and sophisticated approaches will provide results that permit the impact analysis to be more realistic. Table 4.2 shows the inputCAEP/8

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variables that may be needed if the simple, advanced or sophisticated approach is chosen. Exact needs are determined by the model selected.

Table 4.2 Input Data Needed Depending Upon Approach Taken
Key Parameters Simple Approach Advanced Approach Sophisticated

Approach

Emissions As described in Chapter 2 of the guidance

Spatial resolution For Case 1: No

differentiation; airport as one

"emission bubble". For Case 3, very large mesh size using single source

location such as

runways. Defined receptor

positions with spatial

resolutio n on a coarse grid (e.g. not

less than 500m mesh size) Defined receptor

positions with fine grid on a 10 by 10 m mesh size, but not more than 500 by

500 m mesh size

Temporal

resolution Annual total Monthly or daily

resolution Hourly or smaller

resolution Meteorological 1. No weather data.

2. Wind speed is 1 m/s. Wind direction, very stable atmosphere for ground level sources, and no plume rise is used to predict a

conservative estimated (often

referred to as ―worst case‖) concentration

calculated at th e receptor. Mixing height not

considered. Climatological data

for multiple parameters ranging from an hourly to daily average

Turbulence as a single parameter such as a stability

classification generally from only wind speed and cloud

cover consideration s. Average mixing height for area, generally assumed to be 914 meters (3000 feet). Detailed

climatological data

on a small time scale including upper air and specific mixing height data. Multiple derived parameters requiring additional

data such as clou d

cover and

temperature gradients.

Surface Roughness Assume all area is

flat and grass. Consideration of

major topographical

features. Consideration of

topographical features, ground cover, and local buildings. Receptor

Information General locations at

g round level. Specific locations at

ground level. Specific locations

with varying

horizontal and

vertical locations.
Background

Concentration 1. Not considered.

2. Single value for airport area. Single value for

airport area. Temporal and spatial

consider ations

included. Atmospheric Chemistry None Typical (analytical)

transformation ratios

from established

studies. Detailed reaction rate

constants with

consideration of local

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concentrations of reacting chemical species.

The designation 1 in the s imple approach refers to the rollback model approach while 2 is a conservative analysis often referred to as the “worst” case analysis.

It is again noted that many models will not support all variables or require very specific

information and it is the re sponsibility of the analyst to determine which variables are required by any model.

5

. 1 Simple Approach

The simple approach can be thought of in two distinct ways: 1) use of a rollback model in which airport data is lacking except for the overall change in o perations; and, 2) a simplistic so called ―worst case‖ analysis. As in Chapter 2 for emissions, the simple approach is only

recommended when limited data are available or for initial assessments.

5

. 1

. 1

. Rollback Approach

The rollback approach is the most simpl e and requires the least data and as such can be performed very quickly. It is also represents the greatest error. In this approach, which is not actually dispersion modeling, known emissions and concentrations are scaled according to overall changes in the aircraft operations. This assumes all other sources grow or decrease at the same rate as the aircraft operations. Equation 4.2 represents the idea numerically:

[4.2]

Where: Δ 2 = Total Emissions or Local Area Concentration at Time 2

Δ 1 = Total Emissions or Local Area Concentrations at Time 1

O 1,2 = Aircraft Operations in LTOs for time 1 and 2, respectively

5.1.2. Worst‖ Case Analysis

In this analysis, wind speed is ass umed to be the smallest value that provides reasonable answers in a model, typically a constant 1 m/s. The wind is also assumed to be from a direction that produces the greatest concentration at the receptor location. The atmospheric stability is conside red to be very stable for ground level sources and the mixing height is not considered. Background concentrations are assumed to be a single, conservative value. Use of these parameters results in a so

- called ―worst case‖ analysis in that in reality the concentrations would rarely, if ever, be this high. These assumptions lead to the logic that if

criteria or standards are not shown to be exceeded in this conservative estimation where predicted concentrations are most likely at a level greater than would normally occur, then there is not a substantial impact. Simple models can be used and as such this method can be coded into a spreadsheet (such as the use of the Gaussian formulation included in Annex A) or graphs and tables may be used. Simple compute r models may also be used. The advantage is only a small set of data is needed and quick results. The disadvantage is a very conservative prediction that overestimates impacts.

Advanced Approach

In this approach, computer coded models are a must. Specif ic models may be required by the reviewing agency, some models are available in the open domain, or proprietary models mayCAEP/8

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be purchased. Each model will have a user guide and most will have a technical manual for the interested analyst. The analyst must completely review the user manual and be sure of input. The old adage ―garbage in equals garbage out‖ is very true in this case and the result, even for the most complete model is only as good as the input data used. Some models may

include an interactiv e graphical user interface (GUI) to allow input more easily included. If not, input files will have to be created. Some models may have the needed emission factors (or in the case of aircraft emission indices) included to also make input easier. In thes e cases the emission inventory may also be accomplished directly in the model. If this information is not included, the emission inventory will have to first be completed externally. Temporal and spatial allocation may occur at the emission inventory pha se or postponed until the dispersion analysis.

These models may be the same as in the sophisticated approach with the difference being a greater use of default values for input variables, less complete operational data, non

- varying background concentratio ns, and a lesser degree of spatial and temporal definition. Models inputs contain a large amount of ―default‖ values, that is typical values for airports but not actual for the defined airport. Typical models used in the advanced approach for modeling in the vicinity of airports include ALAQS

- AV, AEDT/EDMS 4 , ADMS

- Airport 5 , and

LASPORT 6

.

Sophisticated Approach

This approach requires the most extensive data collection effort to define inputs. Default values are replaced with real data and this is especial ly true of meteorological input. Operational data is very complete with a much greater emphasis on spatial and temporal resolution. The models may be the same as in the advanced approach but with the actual data and a much greater use of options. Typical models used in the sophisticated approach for modeling in the vicinity of airports include ALAQS

- AV, AEDT/EDMS, ADMS

- Airport, and

LASPORT.

Hybrid Approach

As with emissions, the three basic approaches can be mixed according to need and available

data. The simple approach, because of the large simplifications that are made, does not lend itself to the hybrid approach except in very special situations. The advanced and sophisticated approaches are often mixed. This is especially true when the same model is used first with a high number of defaults input values for a high level assessment and then refined to allow more detailed modeling.

6

. MODEL OUTPUTS

Each model has different outputs but some are common to all models. The first is an echo file

of the i nput data when computer models are used. This is an important component of the output because it allows the user to check the input data to 1) be sure of the accuracy of input; 2) make sure the model has interpreted the data input correctly (very importan t for fixed field inputs); 3) evaluate derived parameters by the model which will be reported with the input; and, 4) allow the analyst to store the results and later understand the inputs used.

The most important output of course from all models is the c alculated concentrations. The concentrations will be output as a certain time average (e.g. annual mean or series of daily means), possibly supported by some statistics (e.g. percentiles or exceedance frequencies) or2 C

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even by complete time series (e.g. hou rly means at given receptor points). The units of the concentrations will typically be either parts

- per

- million (ppm) or micro

- grams

- per

- cubic

meter (μg/m 3 ). In the case of particulate matter, only μg/m 3 is valid. The calculated or predicted concentrations including background should then be compared to the ambient air quality standards or criteria with the correct time frame and units.

Some models may also include graphical outputs to assist in determining problem areas or to allow a visualization of changes, for example during mitigation modeling. In the sophisticated approach multiple derived parameters will also be available in the output.

7

. MODELING APPLICATION AND

INTERPRETATION OF RE SULTS

The analyst should be aware of the fidelity of the results. This depends on the model used,

th e accuracy of the input data, and any assumptions applied.

Uncertainty in Dispersion Modeling

Since air pollution dispersion models vary from the simple to the very complex, there is a large difference in the uncertainty from model to model. Hanna 7 points out that total model prediction uncertainty is a combination of parameters including: model physics errors, natural or stochastic uncertainty, and data errors. As the number of parameters increases, the natural or stochastic uncertainty decreases and the model‘s representation of the physical reality becomes better. This leads to more complex models and a greater need for high fidelity input data. However, as the number of input parameters increases, the input data errors may increase. Poor input data c ould cause the more complex model outputs to be equal or even inferior to using more simplistic models. In addition, model adjustments based on limited data

sets can lead to additional error.

This makes it extremely difficult to quantify the uncertainty. Models may perform well in predicting the maximum occurrences but may do poorly when trying to predict concentrations in time and space when compared to measurements.

Limit values and required model results often refer to statistical quantities like pe rcentiles, long

- time averages like annual means, or maximum concentrations independent of their specific occurrence in time or their accurate location. A model may yield reliable results with respect to these quantities even if it shows poor performance in a point

- by

- point comparison, for example with a measured time series at a given location.

Verification Based on Measurements

Complex dispersion models are applied in form of computer programs. In view of quality assurance it is required to verify and vali date such programs. The verification checks whether the program correctly implements the mathematical formulation (algorithms) of the model. The validation then checks how well the model respectively the program describes the reality, usually by a comparis on with measured data sets.

For the validation it is important that these data sets are sufficiently complete, i.e. that the validation test can be performed with the smallest amount of additional assumptions. If assumptions are required or if assumptions have been implemented in the model or the program, it is of importance whether they are based on general grounds or adjusted forCAEP/8

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example to a specific airport or situation. With regard to input data, complex models are usually better able to account for s pecific airport details and are thus more flexible for

v alidation against measured data.

Comparison to Applicable Standards and Criteria

The term impact has been used throughout this chapter. This is because impacts are most often evaluated by comparing the predicted concentrations from the dispersion models to

standards and/or criteria which most often are time

- averaged concentrations based on health effects. The use of these standards has been addressed in earlier chapters and will not be repeated here . However, it is important to realize the connection between dispersion modeling and impact assessment. Results from the emission inventory do not allow this direct impact analysis. It has also to be considered that usually only by conducting dispersion modeling of all contributing sources plus the inclusion of all background concentrations will results be produced that may be directly compared to applicable standards. Modeling uncertainties must still be considered with respect to reporting direct imp acts.

Use of Multiple Runs During Mitigation Considerations

Both the emission inventory and the dispersion analysis results may be used for mitigation purposes. The big difference, as noted in the preceding section, is that the dispersion analysis

resul ts that compare the existing case and multiple future scenarios allows evaluation of changes in local area concentration and directly the changes in impacts that are health related.

Future Advancement in Models

As the understanding of the emission and disp ersion of airport

- related source systems increases, models will be improved to reflect and incorporate these advancements. In addition to model development, combination of microscale (the ones discussed here) and regional modeling are occurring to allow e valuation of the impact at larger distances from the airport and a more detailed consideration of background concentration at the airport.

As advancements occur, agencies and airport authorities will be faced with the need to evaluate and implement modeli ng practices that provide the best impact analysis for the airport. As such, this field is dynamic and any documents such as this one will need to be evaluated over time for possible updating.2 C

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8

. REFERENCES

1 Merriam

- Webster Online Dictionary

. http://www.merriam

webster.com/dictionary/dispersion

.

2 Draper, J., S. Webb, Augustine, Pernigotti, J. Plante, Liang, Air Quality Procedures For Civilian Airports and Air Force Bases, Appendix I: Dispersion Modelling, FAA

- AEE

- 97

- 03, Arlington, VA., April, 1997.

3 Turner, D.B., Workbook of Atmospheric Dispersion Estimates, An Introduction to Dispersion Modeling, 2 nd Ed., Lewis Publishers, Boca Raton, FL., 1994.

4 U.S. EPA, AERMOD, AERMIC Dispers ion Model, http://www.epa.gov/scram001/7thconf/aermod/mod

- desc.txt , last visited May 31, 2005.

5 CERC, ADMS 3, http://www.cerc. co.uk/software/adms3.htm , last visited May 31, 2005.

6 Janicke Consulting, LASPORT 2.0, A program system for the calculation of airport

- induced pollutant emissions and concentrations in the atmosphere, Germany, 2009 http:///

, http://www.janicke.de/en/lasport.html , last visit September 23,

2009.

7 Hanna, S.R., Plume dispersion and concentration fluctuation in the atmosphere, Encyclopedia of Environmental Contro l Technology, Volume 2, Air Pollution Control, Gulf Publishing Company, Houston, Texas, 1989.

8 Pasquill, F., Atmospheric Diffusion, Van Nostrand, New York, 1962.

Dispersion modeling is a relatively new science and development is continuing. In 1895, Reynolds produced a paper discussing laminar to turbulent flow in pipes and has been considered by some to be the starting point of dispersion modeling. Taylor produced one of the first papers on turbulence in the atmosphere in 1915 and in 1921 prod uced the  ̳Taylor theory of turbulent diffusion‘ which provided a basis for describing dispersion with constant eddy diffusivity. Development continued and in 1962, Pasquill published the landmark book ―Atmospheric Dispersion‖ 8 . This work summarized what had been done to that time and is the basis of modern Gaussian plume models based on the horizontal and vertical spread of the plume being determined experimentally as a function of atmospheric stability and distance; the now well known sigma values. The sigma values are in reasonable agreement with the Taylor theory.

There are different types of dispersion modeling methodologies for a dispersion calculation, with different features and capabilities. In the 1960s work on dispersion modeling continued

to expand and formalize the dispersion modeling process including plume rise considerations. This resulted in the basis of the Lagrangian (moving coordinate axis) and Eulerian (fixed axis) modeling we know today. The science has become an accepted approach to prediction of concentrations of pollutants in the vicinity of airports which is directly connected with impact on public health and welfare. Performance of dispersion modeling requires key variables to be carefully assembled and various methodologies h ave occurred. A very brief description of each is included here.CAEP/8

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A.1 Gaussian Formulation

.

The Gaussian formulation is still used more than any other approach. This Lagrangian approach assumes downwind dispersion to be a function of stability class and downwind distance and applies the Gaussian probability density function to account for plume meandering and diffusion. It was released in various forms by the U.S. EPA as part of the UNAMAP series in late 1960s and developments still are on

- going worldwi de. It can be applied to plumes or individual puffs and as such provides needed flexibility for local air quality modeling. It has been adapted for point, line and area sources. In its basic point source form, for a plume, the concentration (c) is predi cted with the following mathematical expression:

where: Q = source strength

u = wind speed h = stack height

ζ y , ζ z = horizontal and vertical dispersion coefficients

Of note is that x, the distance downwind, is included implicitly in the h orizontal and vertical dispersion coefficients that increase with downwind distance.

More recent Gaussian model formulations have used a bi

- Gaussian distribution in the vertical to better account for vertical mixing in convective conditions. This results in more accuracy but also a more complex model.

A.2 Eddy Diffusivity based on Mass Conservation Formulation

.

In this Eulerian approach, the approximate solution of the mass conservation governing equations are used with simplifying assumptions that re late turbulent fluxes <u‘c‘> to concentration gradients, ∂c/∂x i by including an eddy diffusivity term, K i . This results in:

<u‘c‘> =

- K i (∂c/∂x i )

This approach is used for widely or uniformly distributed pollutants where large individual plumes are no t dominant. This occurs for such pollutants as carbon monoxide. This approach has been applied in regional modeling in the form:

where: u x , u y , u z = velocity

c i = concentration of i th species

R i = chemical generation rate of species i

E i = emissions flux

S i = removal flux2 C

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A.3 Box Model

.

The box model is a simplistic mathematical representation of a defined, well

- mixed volume of air (the box) that includes inputs and outputs into the v olume. Since the box is well mixed, the output concentration is equivalent to the concentration inside the box. Multiple boxes may be used in the horizontal or vertical with the output of one box representing the input of the next in a grid approach. Ch emical reactions can be considered in each box. This allows

the mass conservation formulation to be used for each box in this Eulerian method.

A.4 Trajectory Models

.

These models, based on the Lagrangian approach, provide an approximate solution by us ing the governing equations of mass conservation and a coordinate system that moves with the average wind velocity. This approach implies that parcel integrity is reasonably maintained for the length of time of model simulation and assumes that horizontal wind shear, horizontal turbulent diffusions and vertical advective transport are negligible. This model is not generally accepted for general use for regulatory applications in the U.S.

A.5 Mass and Momentum Models

.

In this type of model, governing e quations of mass and of momentum are applied using first order principles. For example, approaches may begin with the fundamental Navier

- Stokes equation and include turbulence based on Reynolds averaging. The result is more scientifically rigorous with c omplex procedures that avoid the K

- theory simplification but are often computer and data intensive and specific to a particular case. As such, this category of

models tends to be more research oriented and not in common use.

A.6 Lagrangian Particle Model s

.

In contrast to Gaussian models which are based on an analytical solution of the classical dispersion equation and Eulerian models which solve this equation numerically, Lagrangian particle models simulate the transport process itself.

Out of the hu ge number of particles (gas, aerosol, dust) usually emitted by a source, only a representative, small sample is considered. The sample size is typically of the order of some million particles, depending on the problem and available computer resources. The trajectory of each of these particles is calculated on the computer by a stochastic process (Markov process in phase space). From these trajectories the three

- dimensional, time

- dependent, non

stationary concentration distribution is derived.

The core of a Lagrangian particle model, as for example specified in the guideline VDI 3945/3 (English/German, see www.vdi.de ), does not contain tuneable parameters. It relies on meteorological parameters that can be determined witho ut dispersion experiments. Time scales typically range from some minutes to one year with a time resolution down to some seconds, spatial scales range from some metres to some 100 kilometres.

Increased research and application to atmospheric physics start ed about 20 years ago and Lagrangian particle models have become more widely used with increased computer speeds and memory storage. Today the technique is routinely applied in air quality control.CAEP/8

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A.7 Plume

- in

- Grid Approach.

This method is a hybrid between the Lagrangian and Eulerian approaches. The Eulerian approach is adapted by using trajectory models or Gaussian dispersion techniques to preserve trace specie concentration to overcome the deficiencies regarding instant mixing of pollutants

in th e grid.

A.8 Closure Models

.

In Eulerian models, vertical diffusion must be addressed. Two different turbulence closure schemes are typically used: local closure and non

- local closure. Local closure assumes the

turbulence is similar to molecular diff usion while non

- local closure assumes the turbulent flux to be similar to mean quantities at different layers and an exchange of mass is allowed.

Closure models are often discussed in terms of first

- order for prognostic equations for the mean variables (i .e., wind or temperature) or higher order models which are more complex. This type of modeling is closely related to eddy diffusivity models previously described.

A.9 Statistical Models

.

This idea is based on statistical analysis of ambient pollutant measurements and other emissions information. This approach is best used when detailed source information is available, as these models have difficulty in applying results as location parameters change. One subset if this type of modeling is receptor mod eling which has been used to predict particulate matter in the U.S. and in the U.K. Receptor modeling uses multivariate statistical methods to identify and quantify the apportionment of air pollutants to their sources.

In sum, this partial listing of pro cedures is meant to provide a background for the discussion of dispersion modeling allowing the analyst to better understand the process.2 C

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ANNEX 4B. Commonly Used Dispersion Models in the Vicinity of Airports

The purpose of this annex is not to recommend any particular model or to show detailed information on any model. The analyst is expected to choose the appropriate model based on legislative requirements, data available, and intent of use.

Table B.1 shows computerized modeling packages that have been commonly used at airports. Of note is that there are many models that have been used and the table is not all inclusive.

TABLE B.1. Commonly Used Dispersion Models at Airports

Airport Air Quality

Model Fundamental Type of

Dispersion Model Model Inform ation

AEDT/EDMS Bi

- Gaussian Sponsoring Organization: United

States

Model Developer: Federal Aviation

Administration

ADMS

- Airport Bi

- Gaussian Sponsoring Organization: United Kingdom

Model Developer: CERC ALAQS

- AV Bi

- Gaussian / Lagrangian Sponsoring O rganization: France

Model Developer: EUROCONTROL

LASPORT Lagrangian Sponsoring Organizations: Germany

and Switzerland

Model Developer: Janicke Cons.

Obvious in all of these reports are that no one modeling approach totally meets all current modeling needs, especially if cost, practicality and complexity are considered. This results in either multiple models being used and selected on a case

- by

- case basis or adaptations/simplifications of the selected model inputs.

The analyst should carefully revie w any legislative requirements, sources to be modelled, inputs needed for any specific model, and limitations of any model when selecting the appropriate dispersion model.CAEP/8

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ANNEX 4C. Climatological Information Sources

Dispersion modeling using the Adv anced or Sophisticated Approach requires detailed meteorological data. Care should be taken in selecting this data. Short term data may not accurately display trends and may not be representative of the seasonal variations, dominant wind patterns, or diu

rnal variations.

The World Meteorological Organization (WMO) ( http://www.wmo.int/pages/index_en.html )

includes:

― more than 10000 manned and automatic surface weather stations, 1000 upper

- air

stations , over 7000 ships, more than 100 moored and 1000 drifting buoys, hundreds of weather radars and over 3000 specially equipped commercial aircraft measure key parameters of the atmosphere, land and ocean surface every day.‖

Information is available for multi ple years and data bases were established prior to 1950.

The World Data Center for Meteorology with 52 centers in 12 countries ( http://www.ncdc.noaa.gov/oa/wdc/index.php ) represents a huge number of monitoring

stations worldwide.

Individual countries may also maintain the required climatological data for a region or country. These include the British Atmospheric Data Centre ( http://badc.nerc. ac.uk/home/index.html ) in the U.K. and the National Climatic Data Center (NCDC) ( http://lwf.ncdc.noaa.gov/oa/climate/climatedata.html ) in the U.S. For example NCDC has directly downloa dable surface data, upper air data, and other useful information in multiple formats. Of importance are the historical records over many years that helps to avoid errors due to incorrect input parameters. The data are available from the 1800s to the

pres ent for over 8000 locations in the U.S. and 15,000 worldwide stations depending upon the

data needed.

Climatological data can be found at many universities world wide as well and often may provide unique data for a region. It is suggested the analyst exp lore this possibility of

information.

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Chapter 5:

AIRPORT MEASUREMENTS

Table of Contents

5.1 Introduction

5.2 Requirements and Drivers for Measurement

5.3 Measurement Plan

5.4 Analysis of Data

5.5 Measurement Quality Assurance / Qualit y Control

Annexe 5A1 Description of Measurement Methods

Annexe 5A2 Examples of Measurement Methods

Annexe 5A3 References

Introduction

5.1.1 Airports are an important part of the economic infrastructure of the cities they serve; passenger and cargo act ivity at an airport support local air transportation needs. However as part of that infrastructure, airports are a magnet for many types of activities that contribute air pollution to the local area: aircraft, automobiles, ground support equipment, statio nary sources, etc. Often responding to various objectives and requirements, airports and/or local authorities seek to obtain an understanding the contribution of airport

- related pollutant sources to the local air quality. While modeling tools are

availab le, some airport locations seek to quantify airport

- related emissions through the conduct of actual air measurements. It is important that measurements conducted for airports comply with the appropriate measurement protocols. This chapter describes the va rious elements for ambient air quality measurements for airports.

Requirements and Drivers for Measurements

5.2.1 Chapter 1 of this guidance material describes the general local air quality regulatory framework and drivers influencing the aviation industr y to provide information or undertake action related to air quality. Specific to ambient air quality measurements, numerous requirements and drivers influence the need for airport ambient air quality measurements to be conducted. Measurements are often c onducted in order to meet legal obligations, as part of voluntary programs, or for model verification.

5.2.2 Legal Compliance : To comply with applicable ambient air quality regulations and accompanying standards or targets for particular pollutants, air ports and in some place local authorities may be required to conduct ambient measurements. An airport or local authority might also be under the obligation (e.g. for baseline assessment or in the context of expansion projects) to perform measurement on a regular or irregular basis.

5.2.3 Voluntary Programs : For example, public and community concerns often trigger the need for measurements to obtain actual information about air quality in the local vicinity. Alternatively, an airport may voluntarily condu ct measurements and report as part of their environmental policy and management

activities.

5.2.4 In addition to public and community concerns, new scientific evidence or hypotheses may emerge that suggest initiating measurement campaigns at or around air ports to seek clarifications or

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5.2.5 Model Verification : Sometimes, model results are calibrated with measured results to determine the ability of a model to characterize current conditions with some degree of confidence. Once a particular model is verified for baseline conditions, it can be used with greater confidence to predict future scenarios accurately. This is particularly important when an airport is considering potential action (e.g., infrastructure development) and needs to analyze the potential impact of the action and any potential mitigation measures.

5.2.6 The major caveat associated with the model verification is the fact that the model usually predicts concentrations from one or several emissions sources b ut not necessarily from all contributing sources. In this case it might be difficult to compare modeled concentrations to measured values, and complex procedures have to be applied for the purpose of actually performing model verifications.

Measurement Pla n

5.3.1 Design Process of a Measurement Plan

5.3.1.1 The measurement plan for local or regional air quality measurements is determined by external and/or internal requirements and the necessary resources available. The following main elements in a plan sh ould be addressed (see also Figure 5

- 1):

1

. Objectives and requirements for measurements (as described in section 2)

2

. External factors

3

. Measurement locations (with respect to the airport premises)

4

. Measurement methods

5

. Management planning

Figure 5

- 1: Measurement Plan Elements

5.3.1.2 The requirements and drivers for local airport air quality measurements are outlined in section Objectives / Requirements Legislative or authoritative Requirements Public Concerns Voluntary Programs
Scientific Issues

Measurement

Locations Measurement Systems

Management

Planni ng External Factors2 C

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5.2. Following the external requirements, airports may have a single or multiple objectives for the

mea surements. Objectives can include the desire to obtain factual information on the actual ambient air quality concentrations at specific receptor locations for communication purposes or to establish long

- term trend analysis to observe the development of air quality at the measurement sites in response to the emission developments.

5.3.2 External Factors

5.3.2.1 The key external factors to be considered in ambient air quality measurements are potentially existing measurement standards, recommendations and guidelines. If applicable, practicable, or available, local or national framework documentation for ambient air quality measurements should be used. This can range from general issues like measurement principles or quality assurance to prescribed

measureme nt systems that have to be put in place.

5.3.2.2 In some cases, airports will have to bear the responsibility and costs for air quality measurements. To this end, the available resources, technical skills and budget may be factors that determine the poss ible scope of air quality measurements.

5.3.2.3 An air quality monitoring network may already be in place that is operated by local authorities or other entities. In this case it would be advisable to coordinate or even harmonise potential measurement pl ans to avoid duplication of similar or identical measurements or to avoid inconsistencies or even

contradictions.

5.3.3 Measurement Locations

5.3.3.1 The objectives and requirements as described in section 2 will help determine the locations of

monitori ng stations. The generic measurement site selection plan in Figure 2 and Table 1 identify the various site characteristics and their relevance within the measurement concept. Air measurements should be conducted upwind and downwind from the airport/airpor t sources while at the same time striving to achieve a source distribution discrimination. To achieve source distribution discrimination, locations should be defined that are most likely dominated by a specific emission source, while other

sources may cont ribute only marginally to the overall concentrations.

5.3.3.2 The following questions are associated with the choice of the measurement locations:

 What are the current (past) pollution concentrations of relevant species near the airport?

 Can airport induc ed impacts be

- at least to some degree

- singled out?

 What is the trend of the pollution concentrations?

5.3.3.3. A generic yet typical site selection plan is illustrated in figure 5

- 2 with each location described and justified in table 5

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Figure 5

- 2: Generic Measurement Site Selection Plan (circled arrow: prevailing wind direct ion) Industry Residential Airport

Terminal 

# 

 

  

 a 

#  b2 C

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Table 5

- 1: Description of Generic Measurement Sites

Number Description of Site Justification

1 Background concentration site,

undisturbed by any polluting

activities This station provides the background and baseline data for the region where the airport is located.

2 All stations (including a and b) are

located within the airport area with intense airport activities. Optionally, stations are located directly upwind and downwind (and sideline) of the runways, often at the airport boundary. It can be expected that these stations will most likely best reflect the airport activities (aircraft and/or handling and infrastructure). Those activities will dominate the pollution concentrations and significant concentration changes will likely be caused by t hese sources.

3 This station is located in a residential

area that is located downwind of the airport, but without a dominant emission source in its proximity. This station will give the average situation of a residential area with permanent housing clo sest to the airport and downwind from it. A source attribution might not be possible, but is not

necessary.

4 This station is located next to a major

traffic road, but still in the proximity of the airport. Road traffic is an important emission source in general. This station reflects road traffic impacts on local air quality in the vicinity of the airport. There is no discrimination for airport related traffic versus any other traffic.

5 This station is located in another

residential area, but downwind o f an

industrial area with emissions. Residential areas could still be subject to increased concentrations. In this case it is important to discriminate emission sources that are not airport related but can impact areas close to the airport.

6 This station is located further away

from the airport, but again in

residential areas downwind of the airport. It can be expected that further downwind from the airport, concentrations will decrease, provided no other significant emission sources are present.

5.3.3 .4 In choosing the locations at and around the airport with regard to most likely dominant pollution contributors, it can be possible to estimate qualitatively the relevance of air traffic and airport induced impacts.

5.3.4 Measurement Methods

5.3.4.1 Va

rious measurement methods are available that can range between simple (in terms of location site and handling) to sophisticated. The choice of each instrument must be made according to the expected measurement exigency. This exigency definition rests on th e analysis of customer or authority demand when it is not compulsory by law. In any case, the risk of providing a wrong result when comparing to a threshold must be discussed and accepted by all "parties".

5.3.4.2 The main difference between measurement s ystems is whether they are active (system collects air samples and analyses continuously) or passive (ambient air is reacting with the system and results will be obtained remote). Table 5

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Table 5

- 2: Active and Passive Measurement Systems

Parameter Active System Passive System 12
Possible Systems Optical Path:

 DOAS (differential optical absorption spectroscopy)

Continuous Point

 TEO M (Tapered Element Oscillating Microbalance)

 Beta

- Attenuation Mass Monitor

 High Volume Samplers

 Chemiluminescence  Bag/Canister

 Passive Diffusion Tubes

 Filter papers

Pollution species to

be measured Usually multiple species can be

measured in one station ( e.g. NO 2 , O 3 , PM10) by using several analysers

in one location. Usually only one pollutant can be measured; some pollutants cannot be measured at all (reactivity).

Analysis Air samples are usually analysed

directly in the station and when sampled. Samples are usually analysed remote in a laboratory and after collection.

Measurement

Intervals Depending on the equipment, the

measurement intervals can be short, e.g. samples can be analysed every

few seconds or minutes. Intervals are usually long (e.g. two

we ek

- intervals) or only one

- time

measurements.

Data Accuracy The accuracy of the data obtained is

usually fairly high, provided proper

installation and maintenance of the

systems. The accuracy of the measured data is fair. However, for trend or comparison a nalysis with a larger number of sites, the accuracy may be

sufficient. Site requirements The measurement site requires an

unobstructed location (with regard to air flow), a sheltered room for the equipment and analysers and access to electrical power. De pending on the system, communication lines for remote operations are also needed.

Some access restrictions should apply. Such a system can also be mobile for measurement campaigns. The measurement site requires an unobstructed location (with regard to

air flow). Only limited infrastructure is required to install the measurement system (no shelter, no power).

Maintenance An increased level of maintenance on

electrical / electronic and precision parts is required to obtain and

maintain a reliable level of

op erability. This may include regular calibration or exchange of critical

parts. Maintenance efforts are usually low as no or only limited electrical / electronic or high precision parts are

involved.

Costs Medium to high (investments) and

medium (maintenan ce). Low (investments and maintenance).

12 Bioindicators/bioaccumulators: This category is more a hybrid of an active system and long

- term exposition. A limited description is given in the Annexe.2 C

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5.3.4.3 By considering potential sites in combination with measurement systems, it can be concluded that sites at the airport could be equipped with active and/or passive systems, while air quality

measurements in the airport region are performed with passive systems.

5.3.5 Management Planning

5.3.5.1 An important element of ambient air quality measurement is assuring that implementation and actual execution is properly accounted for. To this end, several elements have to be addressed, defined and documented in the management planning. These include the following:

 Project Responsibility

 Maintenance

 Data Management

 Communication

 Quality Assurance and Quality Control

5.3.5.2 The project responsibility includes, but i s not limited to the elements of drafting of the measurement concept, acquiring the necessary budget for acquisition, installation, operation and maintenance of the measurement equipment, organising the data management (evaluation, verification, storage) a nd managing potential third party contracts. It defines the roles and responsibilities of all involved parties.

5.3.5.3 Maintenance involves all of the elements of regular and preventative maintenance of the measurement equipment, as well as the repair an d potential contingency planning by having spare equipment available. It also deals with the aspects of calibration of the equipment following manufacturer instructions or general guidelines and recommendations.

5.3.5.4 The data management comprises the data acquisition (automatically or manually), the data storage, and the data transfer (e.g. from remotely controlled stations). Once the raw data is obtained, it is subject to a quality check that needs to be predefined where inappropriate data is being id entified and either marked or removed from the data series. Depending on the data acquisition system and required evaluation and reporting interval, the data might have to be aggregated into a different interval (e.g. hourly value).

5.3.5.5 Once the data is available for proper interpretation, there might be requirements for communication and /or publication. Public or restricted measurement reports may be produced and distributed by means of printed or electronic reports. In addition, communication to aut horities or local stakeholder might be pre

- defined.

5.3.5.6 In order to ensure long term quality of measured data, a quality assurance process is recommended where all elements influencing the quality of the data are addressed. Such a quality control

syst em is developed and implemented to ensure that the required level of confidence in the system and its

results are achieved.

5.4 Analysis of Data

5.4.1 Introduction

5.4.1.1 Ambient air measurement data can be used in a variety of ways, such as:

 Describi ng existing conditions in an area or a site, and demonstrating whether or not ambient air quality standards are being met

 Determining hourly, daily, monthly, and seasonal variation

 Determining trends

 Spatial

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 Identifying major sources that contribu te to measured concentrations

5.4.1.2 How the data can be used is dependent on the:

 specific pollutants or constituents that were measured

 duration (days, weeks, months, or years) of the measurements

 time resolution (seconds, minutes, hours, or longer) of the measurements

 number and location of monitoring sites used to collect the measurements

 meteorological data (e.g., wind speed and direction)

5.4.2 Describing Existing Conditions vs. Ambient Air Quality Standards

5.4.2.1 Ambient air quality monitoring is the traditional method for demonstrating that an area currently meets the applicable air quality standards. Often, monitoring must be conducted for one to three years prior to a formal designation and determination that an area attains or does not attai n a standard. Regulatory agencies have defined how the data may be used in comparing the monitored results with the air quality standards.

5.4.2.2 Monitoring at one or more sites near an airport provides information regarding local air quality in

the vici nity of the airport. This data may be used for defining the existing or baseline conditions in an environmental disclosure document for a proposed future project. Since air quality standards include the averaging period, and the averaging periods for certa in standards are up to one year, monitoring must be conducted for the period appropriate to the standard in which the data will be compared. Longer monitoring may be required if the standard is based on a limited number of measurements that can be

exceeded over a number of years.

5.4.3 Determining Periodic Variations

5.4.3.1 Periodic variations may give some clues as to which sources may be contributing to the measured concentrations. Each source at an airport has associated peaking characteristics. For example, regional surface traffic often follows a morning or evening work

- related period peak. Aircraft operations often have distinct peaks. Ground vehicle access to an airport may peak 60

- 90

- minutes before and after the peak aircraft operations. If hou rly monitored data are available, and these data show pollutant concentration peaks corresponding in time with the rush hour periods, then traffic is likely a major contributor to the measured values. Note that this assumes one is looking at a relatively i nert pollutant (such as CO, PM10, or total NOx).

5.4.3.2 The variation may also be by day

- of

- week, month

- of

- year, or seasonal. These variations may also help point to the sources or source types that may be substantial contributors to the measured

concent rations. However, one should note the periodic variations may also be associated with meteorological effects, such as temperature, mixing height, or relative humidity that actually change either the pollutant emissions from sources. For example, combustion sources produce more NOx and less CO when the ambient air temperature is higher producing both diurnal hourly fluctuations and

seasonal variations.

5.4.3.3 A typical example of a source dependent variation is the pollution concentration of aircraft.

Ther e might be airports with distinct seasonal traffic (e.g. winter sports destination) of even weekend traffic. A typical example of a variation that corresponds with meteorological conditions might that of an airport power plant that operates at fairly regul ar load conditions throughout the year.

5.4.4 Trend Analyses

5.4.4.1 Spatial gradient analysis uses ambient air measurements of a single pollutant made at multiple locations to identify and locate emission sources that contribute to the measurements.2 C

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5 .4.4.2 Time series analysis uses ambient air measurements of a single pollutant made at multiple locations to identify patterns of pollutant concentrations over time.

5.4.4.3 Long

- term (multiple years) data collection at one location can provide informat ion on the general trends in pollution emission. In many areas where on

- going pollution control programs have been in place, the long

- term trend show steady reductions in measured pollutant concentrations over time.

5.4.5 Source Apportionment

5.4.5.1 Sour ce apportionment is the use of monitored or modeled concentrations, with or without meteorological data, to determine the sources, source types, and/or source locations that contribute substantially to measured values. The spatial gradient and time series analyses discussed above are possible source apportionment methods. Others include the chemical mass balance or the positive matrix

factorization.

5.4.5.2 The use of monitored data to determine sources that contribute to the measurements is referred to

a s receptor modeling. The receptor (monitoring station) data is analyzed along with either wind speed and wind direction data or assumed source type emission profiles and characteristics to tease out information about which sources or source types are gener ating the emissions that get measured at the

station.

5.4.5.3 Measurements at a point do not allow one to distinguish from different contributing sources unless a tracer substance can be isolated that is emitted from a specific source only. Therefore, it is important to conduct modeling in conjunction with measurements in order to estimate the contribution from individual sources or groups of sources (e.g., an airport).

5.4.6 Handling of Missing Data

5.4.6.1 Local or national guidelines usually set f orth the required conditions under which measured time series are valid. For longer

- term measurements (e.g. annual), a maximum number of days without data is allowed where no specific action has to be taken. Gaps beyond this tolerance will lead to invalid measurement series or averaging periods. The obtained data can be used for information purposes, but may not be used for legal reporting or justification for mitigation programs. Where such guidelines allow, missing data can be inserted by ways of interpo lation. In all cases, data gaps should clearly be

documented.

5.4.6.2 Interpolation of one or several missing data points can be done by consulting a valid measurement period from a nearby station with comparable meteorological conditions and to use the

v ariation in the measurement points in a corresponding manner. In any case, any interpolated data has to

be marked as such.

5.5 Measurement Quality Assurance/Quality Control

5.5.1 Quality Management Guidelines

5.5.1.1 One of the main targets in quality management is to provide confidence that the measurements are accurate to avoid criticism when communicating the results. The quality management process will help to minimize uncertainty by optimizing equipments performance as well as the technician capabi lities. Furthermore, the monitoring results must be readily available; it must be traceable, well identified, documented and unique in time and location.

5.5.1.2 There may be a number of guidelines available. This could include, but is not limited to

manu facturer specification, local or national guidelines or international guidelines (International Standards Organization). ISO 9001: the reference for quality management, deals with the processes for organizing the measurement information that allows for cus tomer satisfaction. ISO 17025: based on theCAEP/8

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same quality management organization and goal as the ISO 9001 standard, and specially built for measurement activities, adds the technical capability evaluation and is much more constraining than ISO

9001.

5.5.2 Technical Competence

5.5.2.1 An important factor in assuring the quality of measurements is the skill and expertise of staff performing the measurements. As such, adequate technical skills need to be achieved for all elements of air quality monitoring: eq uipment installation, operation, maintenance and repairs and data handling: obtaining, storing, validating and interpreting. The minimum educational level should be defined in

advance and documented.

5.5.2.2 In order to assure the required level of expert ise, a training schedule can be developed that includes internal and external training e.g. by the equipment manufacturer or environmental authorities. This is particularly true for complex analysis instruments with frequently changing technologies. It is recommended to document all training programs (e.g. according to ISO 9001). Training programs have to be on a repetitive basis.

5.5.3 Equipment Accuracy

5.5.3.1 The necessary (preventative) maintenance procedures including the periodicity have to be

pre scribed by the equipment manufacturer. Preventive maintenance must be programmed regularly for the equipment to assure optimum performance during operation, particularly during continuous monitoring and communication of the data. Preventative maintenance c ould include cleaning, change of specific equipment parts, software updates and others. All maintenance activities must be scheduled and documented, as well as the findings after each performed maintenance.

5.5.3.2 Calibration of the equipment is an impor tant, necessary step, and is done to assure that the measurements are accurate and within the given range of the equipment. Calibration is done after regular,

pre

- defined intervals after each preventative maintenance and repair. When additional calibration equipment or substances (e.g. reference gases) are used, they must be quality assured or certified (e.g. expiration date on reference gases). Controlled temperature and humidity may be necessary for specific calibrations and they have to be respected. All information pertaining to the calibration of the equipment has to be logged.

5.5.3.3 Despite all maintenance and calibrations, some uncertainty might remain. It is important to understand the magnitude of such uncertainty and the level of impact it has on the overall measured values in order to determine the degree of fidelity of the final data. An uncertainty study could help determine the various factors and their relevance for ambient measurements and could also suggest ways

to minimize the uncertain ty of the data.

5.5.4 Data handling

5.5.4.1 Depending on the way of monitoring, a large volume of raw data may be compiled over time that requires specific data management. It has to be decided whether both raw and validated/processed data need to be kep t and over what period of time. A suggested way forward would be to keep the raw data for a period of at least 10 years, while the processed data (validate, aggregated, etc) could be kept for more than 10 years.

5.5.4.2 Data storage will require a mainten ance process, such as regularly recopying the data from one medium to another and at the same time crosschecking for data faults (missing, falsified). This data management process has to be documented as well.

5.5.5 Accreditation and Certification2 C

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5.5.5 .1 Periodical checks must be done to be sure that the management procedures are conveniently applied. Internal auditors could be recruited among the employees and trained for this activity.

5.5.5.2 Even if external companies have an established and maint ained quality system, the customer (e.g. the airport) would have to have the confidence in such a system. To this end, the current minimum standard is an ISO 9001 certification label. In addition, the ISO 17025 standard is specifically adapted to

the measu rement activity and, as it combines quality management based on ISO 9001 guidelines with a clear focus on the technicians‘ capability, it is the best way to ensure the customers‘ confidence.

Annexe 5A1 Description of Selected Measurement Methods

A. Ac tive Systems

1. Differential Optical Absorption Spectroscopy ( DOAS)

With the DOAS

- system it is possible to obtain automatic measurements along a path with high resolution. The principle is based on the wavelength dependent absorption of light caused by ga ses. The

DOAS

- equipment includes an emitter and a receiver unit. A light beam with a wavelength between 200 and 700 nm is projected from the emitter to the receiver and passes to an analyzer through a fiber optic cable. In the path, specific gases will abs orb light from known parts of the spectrum. This allows the analyzer‘s computer to measure gases through a spectrometer. Within the spectrometer a grater set splits the light stepwise into the different spectra. The resulting spectrum is now compared with a reference spectrum and the difference calculated to a polynomial. With additional calculations the differential absorption spectrum and finally the concentration of the particular gas is determined. These single

measurements are summarized to 30 minute s values. This system can be used for a range of pollutants including nitrogen dioxide, ozone and sulphur dioxide.

2. Tapered Element Oscillating Microbalance (TEOM) The TEOM (Tapered Element Oscillating Microbalance) allows one to determine the PM 10 - frac tion of

dust. The TEOM

- method is based on the principle that the frequency of an oscillating filter changes with increasing mass. The TEOM takes air samples of known volume, which passes through a filter on the top of the sampling unit. Here all particul ate matter with a particle

- size lager than 10 μm is separated. The air sampling then passes through a second filter on which the particles smaller than 10 μm drop

behind. The concentration of PM 10 is calculated from the changes of the frequency of the filt er

oscillation. The single measurements are summarized to 30 minutes values.

2a. Beta

- Attenuation Mass Monitor (BAM) The BAM is a more rugged and less expensive continuous monitor for PM 10 and for PM 2.5 than the TEOM. It has USEPA certification (EFQM

- 079 8

- 122) as an Equivalent Method to the standard method for monitoring ambient air PM 10 and PM 2.5 . The BAM method uses a stable radio

- active carbon source ( 14 C, 60 uCi), and it measures attenuation of Beta radiation by particulate matter deposited on a filt er medium and relates the attenuation to the mass deposited on the filter. PM 10 or PM 2.5 levels are measured separately, depending on the particle size discriminator placed before the filter collection device.

3. NO X - Analyzer

The NO X - analyzer is used to measure the NO 2 - concentration. The analyzer takes two air samples. One stream passes through and the other stream passes through a convertor that reduces NO 2 to NO. Both samples are analyzed for NO in a single reaction cell, where the chemiluminescence p roduced by the

reaction between NO and O 3 is measured. The instrument alternately measures the total NOx and NO. The difference between the two readings results in a computed NO2 value in the ambient air.CAEP/8

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4. O 3 - Analyser

In the O 3 - analyser, two air samples are collected. The first one passes through a catalyst which converts

O 3 to O 2 . The second sample goes directly into an absorption cell (reference measurement). A detector measures the amount of ultraviolet (UV) radiation transmitted. The O 3 concentration is calculated from

the two reference values. The interval of measurement is 30 minutes.

Conclusions

Automated analyzers allow for the continuous, automated, on

- line and time

- resolved measurement of air pollutants, producing high

- resolution measurement s of hourly pollutant concentrations or better, at a single point. The major drawback of a continuous point/optical path method, such as the DOAS method, is the high cost associated with purchase and maintenance of the analyzers. Consequently, low network density and low spatial resolution of the measurements may result. Mobile laboratories equipped with automated analyzers constitute a useful application of this technique as a tool for measurement programs covering several locations of interest.

B. Pas sive Systems

1 1. Diffusion Tubes

Diffusion tubes are the simplest and cheapest way to evaluate local air quality of gaseous pollutants and can be used to give a general indication of average pollution concentrations over longer time periods ranging from a week or more. They are most commonly used for nitrogen dioxide and benzene (often

with toluene

, ethyl

- benzene

, m+p

- xylene and o

- xylene as BTEX), but are also useful for measuring a number of other pollutants such as 1,3 butadiene

, ozone , sulphur dioxide , e tc.

Diffusion tubes generally consist of a small tube (test

- tube size) normally made of stainless steel, glass orinert plastic, one end containing a pad of absorbent material and the other end is opened for a set exposure time. After exposure, the tubes a re sealed and then sent to a laboratory where they are analysed using a variety of techniques including chemical, spectrographic and chromatographic processes.

It should be noted that diffusion tubes are an indicative monitoring technique that do not offe r the same accuracy as the more sophisticated automatic analysers. Also, since the exposure periods can be several weeks, the results cannot be compared with air quality standards and objectives based on shorter averaging periods such as hourly standards

- it is not possible to detect peak events using diffusion tubes for the same reason. As a result, although diffusion tubes can be used for shorter period assessments, it is

recommended that NO 2 diffusion tube monitoring, in particular, be carried out over a full year as assessments against objectives for annual mean concentrations can then be made.

Diffusion tubes can be affected by a number of parameters that may cause them to over

- read, or under

read, relative to a reference measurement, and for this re ason, best practise is to use three or more tubes at each monitoring point, and co

- locating one set with an existing reference continuous monitor. This2 C

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way any bias can be corrected by referring the results back to the continuous monitor (e.g. chemi

lumine scant monitor for NO 2 ), and comparison between the tubes will identify any anomaly.

It is important to choose sites for diffusion tube monitoring correctly, and the area around the tube

location should allow for the free circulation of air around the tube s, while avoiding areas of higher than usual turbulence such as corners of buildings etc. Care should also be taken to avoid surfaces that may act as local absorbers for the pollutant being measured, and for this reason diffusion tubes should not be

fixed directly on walls or other flat surfaces. Other localised sources or sinks such as heater flues, air conditioning outlets, extractor vents, etc as well as trees and other areas of heavy vegetation, should also

be avoided.

The relatively low cost of diffus ion tubes means that sampling is feasible at a significant number of points over a large area, and this can be useful for identifying relative trends, and also regions of high

concentrations where more detailed studies can then be carried out. Under these circumstances, the cost and difficulty of using more accurate continuous monitoring to carry out the same study would almost certainly prove prohibitive.

2. Bags/Canisters For this measurement technique, a "whole air" sample is collected at selected measur ement sites by drawing an ambient air sample into some sort of container. Most commonly, this could be a bag, glass bulb, steel "bomb" or a stainless steel canister. Stainless steel canisters and bags are the most common collection systems. The collection of an air sample may be enhanced with a small electric pump that actively fills the canister with the ambient air sample.

Once the gas is collected in the canister, it is analyzed off

- site by several different methods (e.g. using solution chemistry). Me asured ambient air components are often various hydrocarbon species.

Data quality issues usually revolve around the recovery of contaminants from the collection vessel. Recovery is a function of several parameters including, the chemical nature of the co ntaminant and the surface properties of the vessel, the vapor pressure of the contaminant, the influence of various other compounds contained in the matrix, and the ability to start with a vessel free of contamination.

Conclusions Passive sampling methods are simple and cost

- effective methods which provide a reliable air quality analysis giving a good indication of average pollution concentrations over a period of weeks or months. Other methods include the use of bubblers for gaseous pollutants and the ana lysis of heavy metals contained in the suspended particulate matter filtrate.

C. Other Methods

1. Bioindicators Biological indicators, or bioindicators, are plant or animal species which provide information on ecological changes in site

- specific conditi ons based on their sensitive reactions to environmental effects. Bioindicators can provide signs of impending environmental problems such as air and water pollution, soil contamination, climate change or habitat fragmentation. They can also provide informa tion on the integrated effect of a variety of environmental stresses and their accumulative effects on the health of an organism, population, community and/or ecosystem. Lichen species are a commonly

- used bioindicator for air quality.

Various methods of i nvestigating indicator species exist, and at the individual organism level the effects of bioaccumulation can be studied. At the population level, studies of morpho

- physiological changes, changes in life cycles, relative health of populations, and populat ion and community structures can all be conducted. Marking and recapturing, establishing sex and age ratios, point, line, plot or plotless surveysCAEP/8

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- 91

of vegetation cover and plant frequencies, etc. are examples of the ecological field methods which are

used.

The data obtained from traditional measurements methods permit control of compliance with current air quality standards and limit values. Data on ambient pollutant concentrations, however, do not allow for direct conclusions to be drawn on potential imp acts on humans and the environment. Evidence of harmful effects can more accurately be provided through use of bioindicators. Bioindicators also integrate the effects of all environmental factors including interactions with other pollutants or climatic

co nditions. This permits the risk of complex pollutant mixtures and chronic effects that can even occur

below threshold values.

The use of bioindicator plants to assess air pollution effects is not very well established. Insufficient

standardization of the techniques and, consequently, the low comparability of the results is one of the major reasons for the poor acceptance of this air quality monitoring methodology.2 C

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Annexe 5A2 Examples of Measurement Methods

Table 5

- A2: Example table of measurement m ethods (from Europe and US)

Pollutant Reference Method Other Methods

Sulfur Dioxide Ultraviolet Fluorescence DOAS

Nitrogen Dioxide and Oxides of Nitrogen Chemiluminescence DOAS

PM 10 Gravimetric TEOM (Advanced)

Beta Attenuation Sticky Tape (Simple)

P M 2.5 Gravimetric

Lead Gravimetric

Carbon Monoxide Gas Filter Correlation

Non

- Dispersive Infrared Spectroscopy (EU)

Ozone Ultraviolet Photometry DOASCAEP/8

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Annexe 5A3 References (selection)

Aeroport De Paris

– Charles De Gaulle, 2006. ― Campagne De Pr elevement De Dioxyde D‘azote Par

Tubes Passifs‖

Carslaw, D.C., S.D. Beevers, K. Ropkins, and M.C. Bell, 2006. ―Detecting and quantifying aircraft and

other on

- airport contributions to ambient nitrogen oxides in the vicinity of a large international airpor t,‖ Atmospheric Environment 40:5424

– 5434.

Chow, J.C., L.W.A. Chen, J.G. Watson, D.H. Lowenthal, K.A. Magliano, K. Turkiewicz, and D.E. Lehrman, 2006. ―PM2.5 chemical composition and spatiotemporal variability during the California Regional PM10/PM2.5 Air Quality Study (CRPAQS),‖ Journal of Geophysical Research , Vol. 111, D10S04, 17 pages.

EPA‘s ambient air quality measurements guidance, http://www.epa.gov/ttn/amtic/cpreldoc.html

FAA, Air Quality Procedures For Civilian Airports & Air Force Bases, April 1 997, and 2004 Addendum, http://www.faa.gov/regulations_policies/policy_guidance/envir_policy/airquality_handbook/media/Hand

book.PDF

Fanning, E., R.C. Yu, R. Lu, and J. Froines, 2007. ―Monitoring and Modeling of Ultrafine Particles and

Black Carbon at the Los Angeles International Airport, Final Report,‖ ARB Contract No. 04

- 325, prepared for the California Air Resources Board and the California Environmental Protection Agency, Sacramento, CA (June 20).

Henry, R.C., 2002. ―Receptor Modeling,‖ Encyclopedia o f Environmetrics, A.H. El

- Shaarawi and W.W. Piegorsch, Editors, John Wiley & Sons, Ltd, Chichester.

Henry, R.C., Y.

- S. Chang, and C.H. Speigelman, 2002. ―Locating nearby sources of air pollution by nonparametric regression of atmospheric concentrations on wind direction,‖ Atmospheric Environment

36:2237

– 2244.

Henry, R.C., 2008. ―Locating and quantifying the impact of local sources of air pollution,‖ Atmospheric

Environment 42:358

– 363.

RWDI, 2003. ―Air Quality Study: Phase 4

- Ambient Air Quality Monitori ng,‖ Toronto Pearson International Airport, Toronto, Ontario, Canada (November 12).

Unique (Flughafen Zürich AG), 2007: "Air Pollution Monitoring," Concept and Description ( www.unique.ch ),

Watson, J.G., J.C. Chow, J .L. Bowen, D.H. Lowenthal, S. Hering, P. Ouchida, and W. Oslund, 2000. ―Air Quality Measurements from the Fresno Supersite,‖ J. Air & Waste Manage. Assoc. 50:1321

- 1334.

Yu, K.N., Y.P. Cheung, T. Cheung, Ronald C. Henry, 2004. ―Identifying the impact of la rge urban airports on local air quality by nonparametric regression,‖ Atmospheric Environment 38:4501

– 4507.

www.heathrowairwatch.org.uk

— — — — — — — —Appendix D

English only

Revised text for the Guidance Manual

Road Ve hicle Inventory ChapterCAEP/8

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A4.3.4 For airport

- related vehicles, emission factors are available from the following

sources:

 U.S. EPA MOBILE6.

 California‘s EMFAC2002.

 CITEPA method based on COPERT

- IV.

 EUROCONTROL ALAQS method based on COPERT

- IV.

A4.4 Model Var iations of Pollutant Emission Factors

A4.4.1 The vehicle emissions models cited in A4.3.4 are provided as sources of current and future road vehicle emission factors, but were originally designed for the purpose of monitoring the effect of national and/or local air quality legislation [MOBILE6, CITEPA]. These models estimate a number of exhaust pollutants including CO, HC, NO

x , PM, SO

x , select HAP and carbon dioxide CO 2 . Evaporative emissions from fuel and PM emissions from

brake

- and tire

- wear are also pro vided in many cases.

A4.4.2 The pollutants relevant to road vehicle emissions are divided in legislated and

non

- legislated groups. The pollutant species that are typically modelled are shown in the following tables. When selecting a model it is important t o note that some vehicle emissions models will report pollutants differently, e.g. some might provide a breakdown of Hydrocarbons and volatile pollutants, whilst others might aggregate these as one pollutant. Among other pollutants that are not included, l ead may need to be calculated if leaded fuel is

still in use and if a leaded fuel emissions factor is available.

Base pollutant Set

– Legislated

The listed in the table indicate the pollutants subject to air quality legislation in one more

nations.

Polluta nt Remarks

CO

HC Some models may provide results per component

pollutant

– see extended set of pollutants below

NO

x (NO 2 + NO) Some models may report NO 2 and NO separately.

SO

x
PM 10

PM 2.5 May be included in the report for PM 10

Extended Set

– no n

- legislated

Some models are able to report an extended set of pollutants if the appropriate indices are

available.

Pollutant Remarks

1.3 Butadiene

Acetaldehyde

Acrolein

Benzene

CO 2 Most models will calculate fuel burn, hence CO 2 can be derived. But as CO 2 is not a LAQ gas we

include it in the extended set.2 C

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Pollutant Remarks

CH 4

Cu

CHCO

HCB Maybe included in HC

N 2 O

NH 3

MTBE

PAH : BaP, BbF, BkF, IndPy Maybe included in HC

PCDD

- F Maybe included in HC

TSP

— — — — — — — —CAEP/8

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APPENDIX D



# Report on the Use of Environmental Management System s (EMS) in
the Aviation Sector

International Civil Aviation Organization (ICAO)

Committee on Aviation Environmental Protection (CAEP)

February 2010CAEP/8

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## Table of Contents

Executive Su mmary i

Chapter 1. Introduction 1

1.1. Background 1

1.2. Methodology 2

1.3. Questionnaire Data 3

1.4. Introduction to EMS 3



### Chapter 2. Questionnaire Participation 5

2.1. Introduction 5

2.2. Sector Characterization 5



### Chapter 3. Environmental Management Dri vers 7

3.1. Introduction 7

3.2. Priority Environmental Issues or Impacts 7



### Chapter 4. Approaches to Environmental Management 8

4.1. Introduction 8

4.2. Application of EMS Standards or Guidelines 8

4.3. Scope of EMS 10

4.4. Other Management Systems in Place 11



### Chapter 5. Performance Monitoring and Communication 13

5.1. Introduction 13

5.2. Performance Monitoring 13

5.3. Communication Methods 14



### Chapter 6. Implementation and Maintenance 16

6.1. Introduction 16

6.2. EMS Implementation 16

6.3. EMS Maintenance 18



### Chapter 7. Benefits and Challenges 21

7.1. Introduction 21

7.2. Implementation Challenges 21

7.3. Benefits of EMS Implementation 21

7.4. Trade

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### Chapter 8. Organizations Without an EMS 23

8.1. Introduction 23

8.2. Environmental Program Ele ments or Principles 23

8.3. Performance Monitoring 25

8.4. Communication Methods 28

8.5. EMS Application and Development Issues 29



### Chapter 9. Recommendations 3 2

9.1. Recommendations 3 2



### Chapter 10. Conclusion 3 3

References 3 4CAEP/8

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## Executive Summary

Pressure on the aviation industry to balance increasing demand with environmental protection is at an all time high. Therefore, an effective approach to sustain operations and meet future environmental requirements is critical. The International Civil Aviation O rganization‘s (ICAO) Committee on Aviation Environmental Protection (CAEP) is the international forum of expertise for the study and development of proposals to minimize the impact of aviation on the environment.

At the seventh Meeting of CAEP (CAEP/7) in February 2007, the Land Use Planning and Noise Management Task Group (TG) was asked to deliver a report at the Eighth Meeting of CAEP in February 2010 providing information on the use of environmental management systems (EMS) and, as appropriate,

make r ecommendations on how the committee could promote the use of EMS within the aviation system. In response, the TG developed an industry questionnaire to learn more about the application and potential value of EMS to aviation organizations. The questionnai re and accompanying introductory state letter were distributed worldwide by member states and industry associations in May 2008. Approximately 326 organizations responded to the questionnaire; these organizations were categorized into five different

secto rs, including air navigation service providers (ANSPs), airlines, airports, manufacturers, and other aviation organizations. After validating the questionnaire data, information from 233 responses formed the basis of this report to CAEP/8 and supported th e development of recommendations.

Approximately 50 percent of questionnaire respondents (a total of 117) apply EMS standards or guidelines, with the majority having an ISO

- 14001 v2004 certified EMS in place. The remaining 116 respondents that have other environmental programs in place have many of the same principles and practices that are required as part of a formal EMS. For those organizations with an EMS, 82 percent have additional management systems in place

— approximately 51 percent of these additio nal systems are integrated or coordinated with the organization‘s EMS. Over the past ten years, EMS implementation has been relatively consistent in the aviation industry. On average, respondents indicated that 6

- 12 months are needed to successfully devel op and implement an EMS. Approximately 71 percent of organizations had assistance with EMS implementation from a consulting or contracting firm.

Regardless of whether the respondent organization had an EMS in place, measuring environmental performance is important for ensuring compliance. On average, the majority of questionnaire respondents communicate environmental performance through a corporate social responsibility report or through their organization‘s website. Environmental areas of regulatory concern were a primary focus of organizations regardless of whether they implemented an EMS or not. 79 respondent organizations without an EMS plan to implement one in the future. These organizations indicated that the most common reason for not implemen ting an EMS was unfamiliarity with EMS approaches. As a result, aviation industry specific EMS implementation guidance was requested by these organizations.

The information provided by respondents forms the basis of two recommendations. These focus on

in creasing awareness of EMS principles and best practices in the aviation sector and establishing practical guidance to assist those organizations that choose to use EMS to enhance the way they manage environmental issues. Awareness and guidance materials s hould integrate existing ICAO environmental tools, guidelines, and manuals. Where possible they should encourage organizations to support higher

level ICAO environmental objectives, consider the collaborative nature of the aviation industry , and

account f or variance in operation type (i.e., sector type) and the level of EMS maturity at the organization.CAEP/8

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Recommendations

Disseminate Report Information

. Within the first year of the CAEP/9 cycle, ICAO should make the information contained in this report pub licly available. A report should be distributed specifically to those organizations who responded to the questionnaire and more broadly, via member states, to the

aviation sectors in their state.

Develop EMS Guidance

. Stand alone EMS guidance should be developed for the end of the CAEP/9 cycle. This should assist organizations to determine how EMS elements and principles can be used to enhance the way they manage environmental issues and provide practical guidance on how these EMS elements and principl es can be implemented/integrated into existing management systems and business

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## Main Report

Chapter 1. Introduction

1

. 1

. Background

Global demand for air travel is estimated to increase significantly in the future. While the benefits of this

g rowth will be substantial, it is likely to be accompanied by an increase in aviation

- related environmental impacts. Local air quality, ambient noise levels, water quality, energy use, and climate change are some of the most prominent impacts of concern. Pressure on the aviation industry to balance increasing demand with environmental protection is at an all time high. Therefore, an effective approach to sustain operations and meet future environmental requirements is critical. Identifying the significan t environmental impacts of aviation, and effectively managing these impacts efficiently through the use of technology, procedures, and policy is likely to play an important role in the sustainable growth of the aviation industry.

1

. 1

. 1

. ICAO and the Environmen t

The International Civil Aviation Organization (ICAO) is a specialized agency of the United Nations created in 1944 to promote the safe and orderly development of global air transport. ICAO‘s work on the environment focuses primarily on those problems th at benefit most from a common and coordinated approach on a worldwide basis, namely aircraft noise and engine emissions. The following environmental goals have been established by ICAO:

 limit or reduce the number of people affected by significant aircraft noise;

 limit or reduce the adverse impact of aviation emissions on local air quality; and

 limit or reduce the impact of aviation greenhouse gas emissions on the global climate.

ICAO‘s Committee on Aviation Environmental Protection (CAEP) is the internati onal forum of expertise for the study and development of proposals to minimize the impact of aviation on the environment. Membership consists of experts from members and observers from states, including intergovernmental

and non

- governmental organizations representing aviation industry and environmental interests. CAEP is responsible for conducting studies and recommending measures to minimize and reduce aviation‘s impact on the environment, and for maintaining certification standards for aircraft noise a nd aircraft engine emissions. Recommendations made by CAEP are reviewed and adopted by the ICAO Council. The Council reports to the ICAO Assembly where the main policies on aviation environmental protection are defined and translated into Assembly Resolu tions.

Since its creation in 1983, the role of CAEP has progressively expanded from one of basic standards setting, to the development of broad policy measures such as the balanced approach to limit or reduce the impact of aircraft noise, and the creation of market

- based measures to handle noise and emissions charges and emissions trading. In order to achieve a greater understanding of the environmental impacts of aviation, CAEP encourages research through the collection, generation, analysis, harmonizati on, exchange, and dissemination of information related to aviation environmental issues. CAEP‘s work often results in published reports, guidance material, and/or specific studies.CAEP/8

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1

. 1

. 2

. CAEP/8 EMS Task

Environmental management systems (EMS) provide a methodol ogy and framework to systemically identify and cost

- effectively manage significant environmental aspects of aviation organizations‘ operations. They have proven effective across a wide range of organizations, including airports, air carriers, manufacturer s, and government agencies. As a result, international recognition of the potential value of EMS as a tool to help aviation organizations manage their environmental issues is increasing. ICAO would like to further understand the application of EMS by avi ation organizations, encourage implementation where this may help organizations overcome environmental challenges, and better use environmental opportunities.

At the Seventh Meeting of CAEP (CAEP/7) in February 2007, the Land Use Planning and Noise Manag ement Task Group (TG) was asked to deliver a report at the Eight Meeting of CAEP in February 2010 providing information on the use of environmental management systems (EMS) and, as appropriate, make recommendations on how the committee could promote the us e of EMS within the aviation system. In response, the TG formed an ad hoc group to perform the task and proposed a questionnaire to gather information for the report. The US Federal Aviation Administration agreed to lead the effort and an ad hoc group wa s formed with representatives from Transport Canada, Italy, International Coordinating Council of Aerospace Industries Associations, International Air Transport Association, and Airports

Council International.

The TG developed an industry questionnaire to learn more about the application and potential value of EMS to aviation organizations. The questionnaire and accompanying introductory state letter were approved by the ICAO Secretary General on 16 May 2008. The questionnaire and letter were distributed worldwide by member states and industry associations. Approximately 326 organizations responded to the questionnaire over a period of six months. After validating the questionnaire data, information from 233 responses formed the basis of the report to C AEP/8 and supported the development of

recommendations.

1

. 1

. 3

. Objectives

The CAEP/8 task was to:

 “deliver a report providing information on the use of EMS among airports, airlines and air navigation providers in order to give a base of understanding in the av iation sector;” and

 “based on the report, as appropriate, make recommendations on how the committee could promote the use of EMS with in the aviation sector.”

1

. 2

. Methodology

TG1 developed an industry questionnaire based widely on input from members of the w orking group to gain an understanding of environmental management practices in the aviation sector. This questionnaire was divided into eight sections that seek to understand the responding organization and their environmental management practices by inqu iring about the following:

 environmental management drivers;

 approach to environmental management;

 performance monitoring and communication methods;

 resources required for implementation and maintenance; and

 lessons learned.CAEP/8

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After several revisions by th e TG, the questionnaire was finalized and an electronic version of the survey was developed so respondents could submit their responses online. On 16 May 2008, the questionnaire was distributed by states and industry associations with an accompanying intr oductory letter signed by the ICAO Secretary General.

Over a six month time period, responses were received via mail, fax, email, or through the questionnaire software program. All questionnaire responses were input into the questionnaire software progra m, either manually or directly depending on the method of submission. Once all responses were input into the questionnaire software program, the response data was validated based on the resolutions that were agreed on by the TG (Section 1.3. outlines the validation process that was used).

Following validation, individual sector data was forwarded to the appropriate industry association so a summary analysis could be conducted to characterize the respondents in a given sector. After the response data was validated and characterized by the appropriate industry association, the remaining response data was analyzed and formed the basis of the report to CAEP/8.

1

. 3

. Questionnaire Data

As a result of the number and range of organizations from different countries th at responded to the questionnaire, variation in the data exists. Common inconsistencies found among questionnaire responses included the submission of partially completed surveys; receiving multiple, different responses from the same organization; and hav ing questionnaires with response data for both question sets, those for organizations with EMS and those for organizations without EMS. It was critical that data be as consistent as possible for strong informative analysis. Therefore, the TG developed re solutions for how common inconsistencies should be addressed prior to analysis. The resolutions agreed on by TG were as

follows:

1

. Delete those responses from the data set that provide no information on the organization‘s environmental management practices

.

2

. Delete those responses from the data set that are exact duplicates.

3

. Request clarification from industry group or respondents for those responses that are from the same organization, but not exact duplicates.

4

. Review data specifically by sector to see w hat can be done about inconsistent financial figures.

5

. Request clarification from industry group or respondents for those responses that claimed they do not apply EMS standards/guidelines, but completed both sets of questionnaires for organizations

with EM S and without EMS.

6

. Delete the completed question set for organizations without an EMS for those organizations that claim to have an EMS and completed the question set for organizations with an EMS.

7

. Change the organization‘s response to the question regar ding whether or not they have an EMS to reflect the question set that they answered.

8

. Delete those responses from the data set that do not provide sufficient information on the organization to validate that the response is accurate.CAEP/8

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Of the 326 responses r eceived, approximately 93 were not considered for analysis as a result of the agreed upon resolutions. The remaining 233 responses form the basis of the report to CAEP/8 and support the development of recommendations.

In addition to variation in the data , it should also be noted that the questionnaire respondents do not make up a random sample. The questionnaire and accompanying introductory letter that was distributed to industry associations and states encouraged the participation of all organizations in the aviation sector. However, since questionnaire participation was voluntary, those organizations who responded to the survey were more likely to have an environmental program in place. As a result, the sample of respondents is not representative of the aviation industry as a whole.

1

. 4

. Introduction to EMS

As one of the most environmentally friendly forms of transportation, aviation organizations are increasingly using EMS among other approaches to meet their environmental challenges. A formal

definitio n of EMS, developed by Transport Canada, is as follows:

“A systematic approach for organizations to bring environmental considerations into decision

- making and day

- to

- day operations. It also establishes a system for tracking, evaluating and communicating environmental performance. An EMS helps ensure that major environmental risks and liabilities are identified, minimized and managed.”

Formal Environmental Management Systems (EMS) emerged in the early 1990s to provide organizations with a proactive, sys tematic approach for managing the potential environmental consequences of their operations. Such systems have been widely adopted by industry and Government and have been effective at improving an organization‘s regulatory compliance and environmental per formance. Although several recognized EMS frameworks exist, most are based on the International Organization for Standardization‘s

ISO

- 14001 EMS standard, described by Figure 1.1.

Figure 1.1 : ISO

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Environmental Policy The org anization establishes an environmental policy which provides an overaching vision and framework for environmental management at the organization.

Planning The organization identifies how its operations might harm the environment, and develops objectives, targets, and programs to reduce this harm.

Implementation and Operation The organization implements the systemic measures to control operations and reduce environmental impacts across all levels and functions of its operations.

Checking The organization assesses its environmental performance and the effectiveness of its management system

elements.

Management Review Based on its assessment of the implemented systemic measures, the organization undertakes actions to make system adjustments and to promote continual improvement.

The EMS continually moves through this cycle, fine

- tuning the management of those operations that harm the environment. This ―continual improvement cycle‖ is a fundamental characteristic of the EMS; it allows the system to adapt to the dynamic nature of the organization‘s operations and external conditions.

Chapter 2. Questionnaire Participation

2

. 1

. Introduction

With the assistance of CAEP member states, observer organizations, and industry associations, questionnaires were dissemina ted worldwide to a wide range of stakeholders within the aviation industry. A total of 326 responses were received over a six month time period. Following validation, 233 of these responses were analyzed to form the basis of this report. This chapter wi ll discuss and analyze the breakdown of these 233 responses by industry sector and geographic location.

Figure 2.1 : Number of valid survey respondents within each aviation industry sector.

Sector Characterization

Airlines 80 Air Navigation Service Prov iders 24 Airports 96

Manufacturers 10

Other 44

TOTAL 254

Note : CAEP received a total of 233 unique survey responses. When selecting a sector, respondents were able to choose multiple options.CAEP/8

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Asia & Pacific

Eastern & Southern Africa

Europe & North Atlantic

Middle East

South America

Western & Central Africa North America, Central America

& Caribbean Figure 2.2 : Number of CAEP survey respondents within ea ch ICAO region.

2

. 2

. Sector Characterization

Individual sector response data was forwarded to the appropriate industry association for completion of a summary analysis that characterized the respondents in a given sector. These analyses contain statistic al data specific to the questionnaire respondents and offer some insight on how representative these respondents are of the industry as a whole. In addition, each analysis provides an illustration of the geographic location of questionnaire respondents by sector.

2

. 2

. 1

. Airlines

A total of 80 questionnaire respondents out of 233 were from passenger, cargo, or passenger and cargo

airlines. These  ̳Airline‘ respondents transported an estimated 1.1 billion passengers and 55 billion ton kilometers of cargo in 2008. This represents approximately 67% of total system

- wide scheduled passengers and 33% of total system

- wide scheduled cargo carried by IATA member airlines in that year. Of the 80 airline respondents, 57 (or 71%) were IATA members.

2

. 2

. 2

. Air Navigation Service Pr oviders

A total of 24 questionnaire respondents out of 233 were from air navigation and air traffic service providers. Of the 24  ̳Air Navigation Service Provider (ANSP)‘ respondents, 18 are members of the Civil Air Navigation Services Organization (CANSO) . Together, the CANSO member respondents move an estimated 57,370,000 aircraft per year.

2

. 2

. 3

. Airports

A total of 96 questionnaire respondents out of 233 were from airport companies, airport authorities, and government and city departments that operate one or more airports. These  ̳Airport‖ respondents operate a total of 231 airports that have an estimated annual passenger throughput of approximately 1.15 billion.

The 96  ̳Airport‘ respondents represent approximately 17 percent of Airport Council Internation al‘s (ACI‘s) 597 member organizations, and 5.7 percent of the 1,680 airports in ACI. In terms of passenger numbers, the 96 responses cover almost a quarter of the 4.8 billion passengers handled at ACI member airports annually.

41

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16

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2

. 2

. 4

. Manufacturers

A total of 10 questionnaire respondents out of 233 are from aircraft and engine manufacturers. These  ̳Manufacturer‘ respondents represent approximately 50 percent of the International Coordinating Council of Aerospace Industries Association (ICCAIA) membership.

2

. 2

. 5

. Other

A total of 44 questionnaire respondents out of 233 were from a variety of  ̳Other‘ organizations including fixed base operations, corporate aviation flight departments, aviation academies and flight schools, and aircraft and engine maintenance organization s. When completing the questionnaire, respondents were able to identify themselves as belonging to multiple sectors. As a result, approximately 83 percent of

those that identified themselves as  ̳Other‘ also identified with one or more of the alternative sectors as
well.

Chapter 3. Environmental Management Drivers

3

. 1

. Introduction

The projected growth of aviation and accompanying environmental effects has changed the priority of

some traditional aviation

- related environmental issues and resulted in the emer gence of some new concerns. This chapter discusses and analyzes the priority of environmental issues and impacts to aviation organizations including those that are currently most important. Where applicable, the analysis and discussion investigates trend s by industry sector.

3

. 2

. Priority Environmental Issues or Impacts

Respondents were asked to rate the importance of various environmental issues or impacts to their organization. Rating scores were tallied and the level of importance with the highest percent age of votes for each issue or impact was identified. Figure 3.1 lists those environmental issues with agreement across each of the five sectors as to their level of importance. According to the respondents, these are the environmental issues of highest and medium importance to the aviation industry today. There was no consensus across industry sectors as to the issues or impacts that might be of importance in five or 10 years time, or of those that will never be important.

Figure 3.1 : Areas of environm ental concern across all aviation industry sectors.

Environmental Issue or Impact Importance Today High Medium

Aircraft Noise  Noise from ground activities 
Fuel efficiency 

Financial  Compliance with laws and regulations  State/country p olicies  Company core values and ethics  Global climate change 

Non

- governmental organizations  Corporate commitment and vision  Capacity and growth constraints  Soil and water protection CAEP/8

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Energy management 

Materials and chemicals management 
Operational efficiency 

Customers and other stakeholders' concerns 

Note : Agreement was identified through comparison of categories with the highest respondent percentage across all five sectors.

Respondents rated each environmental issue against six levels of importance: very important now, medium important now, likely to be important in 5 years, likely to be important in 10 years, will never be very important, and not applicable. Only one level of importance could be assigned to ea ch environmental issue or impact.

Chapter 4. Approaches to Environmental Management

4

. 1

. Introduction

Aviation organizations are increasingly challenged to meet new market demands in a manner that is environmentally sustainable. In response to this challenge , organizations are using EMS approaches to manage environmental issues. This chapter discusses and analyzes the approaches that aviation organizations are using to manage their environmental issues. Where applicable, the analysis and discussion investig ates trends by industry sector.

4

. 2

. Application of EMS Standards or Guidelines

EMS standards or guidelines are employed by 117 or approximately 50 percent of the questionnaire respondents across all five sectors. The number of organizations within each secto r that apply EMS standards or guidelines is illustrated below in Figure 4.1.

Figure 4.1 : Organizations that use EMS standards or guidelines within each aviation industry sector.

Aviation Industry Sector Use of EMS
Air Navigation Service Providers 6

Airl ines 42 Airports 54

Manufacturers 8

Other 19

129

Note 1 :Of the 129 organizations that use EMS standards or guidelines, 117 are unique respondents. 12 respondents were included in multiple sectors.

Note 2 : CAEP received a total of 233 survey

respons es from across all five sectors.

The types of EMS standards or guidelines used by respondents in each sector are displayed in Figure 4.2 below. The majority of respondents (57 total) in four of the five sectors have implemented an ISO

- 14001

v2004 certi fied EMS. Other commonly used EMS standards include the application of organization appropriate EMS elements (27 total) and the implementation of a formal EMS based on ISO

- 14001 or the

Eco

- Management Audit Scheme (EMAS) but without third

- party certificati on (24 total). Across all five sectors, eight organizations were registered to EMAS.CAEP/8

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Figure 4.2: EMS approaches to managing environmental issues by aviation industry sector.

4.2a

– Air Navigation Service Providers 4.2b

– Airports

4.2c

– Airlines 4. 2d

– Manufacturers

4.2e

– Other

ISO

- 14001 certified

EMAS registered

Self

- declar e ( ISO

- 14001 or EMAS)

Mixed ( ISO

- 14001 certified / self

- d eclare )

Apply EMS elements as appropriate

OtherCAEP/8

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4

. 3

. Scope of EMS

In order to understand the extent of EMS implement ation within respondent organizations, survey participants were asked to identify the elements of their organization currently within the scope of their EMS. Figure 4.3 illustrates how much of the respondents organization was included within the scope of their EMS (e.g., is the entire organizations and all its operations included within the EMS scope or are only select facilities or operations covered by the EMS). Most respondents indicated that 100% of their organization (i.e., all facilities and operati ons) were covered by the scope of their EMS.

Figure 4.3: The percentage of the organization included in the scope of the EMS.

Sector Percentage of the Organization Included in the Scope of the EMS

< 30% 30%

- 60% 60

- 90% 90

- 100% 100%

ANSPs 1 0 0 0 3

Ai rports 4 3 1 5 37

Airlines 2 6 4 5 8

Manufacturers 0 0 1 0 4

Other 1 0 0 3 10

Respondents were also asked to identify the activities or operations that they currently include in their organization‘s EMS. Figure 4.4 lists those functions that were inc luded or excluded from EMS scopes across each of the five sectors. Note that of the 28 activities and operations included in the questionnaire,  ̳Catering centers‘ is the only item typically excluded from an EMS‘s scope.CAEP/8

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Figure 4.4: Activities and operat ions concurrently included or excluded from the EMS scope across all

aviation industry sectors.

Organization’s Activity or Operation EMS Scope

Included Excluded Engineering/maintenance operations 
Catering centers  Facility management 

Staff en vironmental training 
Organization organizational structure and policies  Environmental accounting 
Environmental performance criteria 
Environmental auditing 
Energy management 
Soil and water protection 
Waste management 

Material s and chemicals management 
Air quality monitoring 
Noise exposure monitoring  Ground transportation 
Procurement policies/supplier requirements 
Ecology conservation 

Note 1 : Agreement was identified through comparison of categories with the highest respondent percentage across all five sectors.

Note 2 : An activity or operation was listed as „Excluded‟ if the highest respondent percentage across all five sectors was „Don‟t know / Not applicable‟.

Respondents categorized each function ba sed of the following scope options: included in EMS, likely to be included within 5 years, likely to be included within 10 years, and don‘t know/not applicable. Only one scope option could be assigned to each activity or operation.

4

. 4

. Other Management Syste ms In Place

Out of 117 respondents with an EMS, 82 percent have one or more additional management systems in place. The percentage of respondents with either a Safety Management System (SMS) or a Quality Management System (QMS) is high for all sectors (Se e Figure 4.5). However, in four of the sectors (Airports, Airlines, Manufacturers, and Others) the most common addition to an EMS was a QMS.CAEP/8

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Figure 4.5: Management System types in addition to EMS within each aviation industry sector.

4.5a

– Air Navigat ion Service Providers 4.5b

– Airports

Additional Management System in Place

Safety Management System (SMS) 48% Quality Management System (QMS) 52% Other Management System 13% No Additional Management System 26%

Note : Percentages based on 54 Airport

responses.

4.5c

– Airlines 4.5d

– Manufacturers

Additional Ma nagement System in Place

Safety Management System (SMS) 75% Quality Management System (QMS) 100% Other Management System 13% No Additional Management System 0%

Note : Percentages based on 8 Manufacturer

responses.

4.5e

– Others

Additional Management System in Place

Safety Management System (SMS) 37% Quality Management System (QMS) 74% Other Management System 11% No Additional Management System 21%

Note : Percentages based on 19 Other

responses.

Approximately 51 percent of respondents with addit ional management system(s) in place have integrated or coordinated it with their EMS. Most respondents with integrated systems suggested the greatest

benefits to be:

1

. the sharing of system procedures and processes, which helps to avoid duplications of eff ort and increase efficiency; and

2

. the ability to manage diverse operations in a more integrated manner. Additional Management System in Place

Safety Management System (SMS) 67% Quality Management System (QMS) 50% Other Management System 17% No Additional Management System 17%

Note : Percentages based on 6 ANSP

respon ses.

Additional Management System in Place

Safety Management System (SMS) 64% Quality Management System (QMS) 95% Other Management System 19% No Additional Management System 5%

Note : Percentages based on 42 Airline

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Chapter 5. Performance Monitoring and Communication



### 5

. 1

. Introduction

As aviation organizations adapt to meet industry demands in an environmentally susta inable way, demonstrating and communicating environmental performance to stakeholders is becoming increasingly important. This chapter discusses and analyzes the value of EMS in assisting aviation organizations to manage a broad range of environmental iss ues, impacts, and regulations. It also describes the types of environmental targets that aviation organizations set, the approaches used to measure performance, and the methods that are employed to communicate their EMS. Where applicable, the analysis an d discussion investigates trends by industry sector.



### 5

. 2

. Performance Monitoring

Respondents that have an EMS in place were asked to rate how helpful their EMS is in managing and controlling their organization‘s various environmental issues. Figure 5.1 lists those environmental issues with consensus across each of the five sectors as to their level of helpfulness. A ccording to the respondents, these are the areas of environmental concern in which EMS is most helpful to the aviation industry today. There was no consensus across industry sectors as to the helpfulness of EMS in managing environmental issues of medium importance today, those that might be of importance in five or 10 years time, or of those areas in which EMS will never be helpful.

Figure 5.1: Consensus areas of EMS helpfulness towards managing and controlling environmental

concerns across all aviation industry sectors.

Environmental Issue or Impact Very Helpful Today
Compliance with laws and regulations  State/country policies 
Company cor e values and ethics  Corporate image  Soil and water protection 
Waste management 
Energy management 

Note : Agreement was identified through comparison of categories with the highest respondent percentage across all five sectors.

Respondents r ated each environmental issue against six levels of EMS helpfulness: very helpful now, medium helpful now, likely to be helpful in 5 years, likely to be helpful in 10 years, will never be very helpful, and not applicable. Only one level of helpfulness cou ld be assigned to each environmental issue or impact

.

Respondents indicated that one of the most important reasons why environmental performance is measured is to ensure compliance. The questionnaire asked participants to list the five most important

env ironmental regulations in which their organization‘s EMS ensures compliance. As a result of global participation in the questionnaire, various environmental regulations were identified as important and

there was no clear consensus on which laws were the m ost significant. The results were thereforeCAEP/8

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categorized into areas of environmental concern, which were then tallied and ranked to identify the top five areas in which the survey respondents ensure compliance (Figure 5.2).

Figure 5.2: Top five areas of e nvironmental regulatory concern.

Important Environmental Regulation Areas

Hazardous/solid waste 54%

Water 40% National environmental regulations 38%

Air 34%

Noise 26%

Note : Percentages based on 115 respondents.

The management and disposal of hazard ous and solid waste is the most important environmental area in which respondent organizations ensure compliance. Second, legislation that regulates the quality, management, and use of storm water, waste water, and drinking water was important to 40 perce nt of questionnaire respondents. Many respondents indicated that they ensure compliance with the national environmental legislation in place in each country in which their organization operates. The national environmental legislation that was identified by respondents typically regulated general environmental concerns such as environmental protection and conservation. The fourth most important regulated environmental area was the quality and management of air emissions, in particular carbon dioxide.

Las tly, respondents indicated that regulations that focused on noise were also important.

In addition to compliance, questionnaire respondents stated that other important reasons to measure environmental performance include the tracking and monitoring of pro gress towards achievement of environmental objectives and for the purpose of reporting performance to stakeholders and the public. Respondent organizations typically measure performance through environmental audits and the use of key performance indicator s. The environmental targets set by questionnaire respondents are directly aligned with the environmental areas in which organizations ensure compliance. In general, respondents are looking to reduce their consumption of energy, waste, water, emissions, and noise. On average, environmental targets and objectives are set no more than five years into the future.



### 5

. 3

. Communication Methods

As depicted in Figure 5.3 below, the most common methods of communicating environmental performance across all five sectors are through the use of sustainability or corporate social responsibility (CSR) reports and through the organization‘s website. The third most common method of external communication employed by Airport and ANSP respondents is to use community meetings as a forum for informing stakeholders and the public. In contrast, Manufacturer, Airline, and Other respondents prefer the use of newsletters over community meetings. In all sectors there were some organizations who listed other means of communicating envir onmental performance, these include: presentations at conferences, internal meetings, press releases, and magazines and other publications.CAEP/8

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Figure 5.3: Methods for communicating environmental performance used by organizations within each

aviation indust ry sector that have implemented an EMS.

5.3a

– Air Navigation Service Providers

5.3c

– Airlines 5.3d

– Manufact urers 5.3b

– AirportsCAEP/8

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Chapter 6. Implementation and Maintenance

6

. 1

. Introduction

A wide range of approaches can be used to implement an EMS depending on the nature of the organization‘s operations and future plans. This ch apter discusses and analyzes the resources and time needed for EMS implementation, including training. It also discusses the resources needed to operate and maintain an EMS, as well as the length of time the organization has operated their EMS. Where

app licable, the analysis and discussion investigates trends by industry sector.

6

. 2

. EMS Implementation

Respondents were asked to indicate when their EMS was implemented as well as the length of time they felt was necessary to successfully implement the system wi thin their organization. The same trends were found among all five sectors; and therefore responses were aggregated at the industry level. Figure 6.1 shows EMS implementation to have been relatively consistent within the industry for the past 10 years.

Figure 6.1: Average length of time EMS has been in place across all aviation industry sectors.

Figure 6.2 below indicates that most organizations (46 total) required 6

– 12 months to fully develop and implement their EMS. Very few organizations (8 tota l) were able to accomplish this task in less than six 5.3e

– Other

Sustainability / CSR Reports

Websites

Newsletters

Community Meetings

Other

0

- 2 years

2

- 3 years

3

- 5 years

6

- 10 years

> 10 yearsCAEP/8

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months, and many (63 total) needed one to two years to fully deploy their systems. EMS implementation typically takes longer in large organizations and those with complicated operations. Approximately , 71 percent of the 117 respondents with an EMS in place sought outside assistance from a consulting or contracting firm in order to implement the system.

Figure 6.2: Average time taken to implement EMS across all aviation industry sectors.

Figure 6. 3 provides a rough estimate of the average level of resources necessary for EMS implementation within each of the five sectors. Note that the averages for each sector are based on the total number of question respondents and do not necessarily reflect all questionnaire respondents for each sector. The estimates provided by respondents on the length of time necessary for implementation are higher than those identified in Figure 6.2. The Airline, Airport, and Other sector results indicate that implementatio n takes approximately 14

– 15 months. Manufacturers and ANSPs provided estimated longer implementation times with ANSPs estimating about 3.5 years for implementation. The results indicate that, on average, a minimum of five employees are required during EM S implementation. Both Airports and Manufacturers provided larger estimates of 26 and 34 employees necessary for implementation, respectively. All five sectors estimated the need for at least two additional employees during EMS implementation with the Ma nufacturing sector respondents going so far as to estimate an average need for 20 additional staff. Within each sector, the estimates for the number of employees necessary for implementation varied by organization size. 0

- 6 months

6

- 12 months

12

- 18 months

18

- 24 months

> 24 monthsCAEP/8

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Figure 6.3: Average resource use for EMS implementation within each aviation industry sector.

6.3a

– Air Navigation Service Providers 6.3b

– Airports

Implementation Resource Average

Implementation time (months) 15.3 Employees used 26.3 Employees h ired for implementation 2.3 Contractor support costs (USD) $62,950 Equipment costs (USD) $209,114 Certification / registration costs (USD) $9,966

Note : Averages based on 54 Airport responses.

6.3c

– Airlines 6.3d

– Manufacturers

Implementation Resource Average

Implementation time (months) 21.4 Employees used 33.5 Employees hired for implementation 19.6 Contractor support costs (USD) $42,500 Equipment costs (USD) $0 Certification / registration costs (USD) $120,000

Note : Averages based on 8 Manufacturer

responses.

6.3e

– Others

Implementation Resource Average

Implementation time (months) 15.2 Employees used 11.2 Employees hired for implementation 5.8 Contractor support costs (USD) $89,591 Equipment c osts (USD) $33,344 Certification / registration costs (USD) $9,778

Note : Averages based on 19 Other responses.

Contract support costs ranged between $42,000

– $90,000 for four of the five sectors (Airports, Airlines, Manufacturers, and Others). ANSP r espondents indicated an average cost for contractor support of more than $500,000. Estimates for the average cost of equipment ranged from $10,000

– $34,000 for three of the five sectors (ANSPs, Airlines, and Others). Manufacturer sector respondents did no t provide an estimate for their equipment costs and Airports sector respondents estimated an average equipment cost of $209,114. EMS certification and registration costs for three of the five sectors (Airports, Airlines and Others) ranged from $9,700

– $13, 000. ANSP and Manufacturer sector respondents estimate average EMS certification and registration costs to be much higher at $100,000 and $120,000 respectively. However, it is important to note that the monetary figures provided as part of the survey res ponses were rough estimates and caution should therefore be taken when using them to represent industry or sector trends.

6

. 3

. EMS Maintenance Implementation Resource Average

Implementation time (months) 41.0 Employees used 5.7 Employees hired for implementation 4.3

Contractor support costs (USD) $544,429 Equipment costs (USD) $10,000 Certification / registration costs (USD) $100,000

Note : Averages based on 6 ANSP responses.

Implementation Resour ce Average

Implementation time (months) 13.9 Employees used 9.5 Employees hired for implementation 2.9 Contractor support costs (USD) $51,542 Equipment costs (USD) $19,699 Certification / registration costs (USD) $12,976

Note : Averages based on 42 A irline responses.CAEP/8

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Figure 6.4 provides a rough average estimate of the level of resources necessary for EMS operation and maintenance (O &M) for each of the five sectors. Note that the averages for each sector are based on the total number of question respondents and do not necessarily reflect all questionnaire respondents for each sector. For three of the five sectors (Airports, Airlines , and Other), time necessary for operation and maintenance ranges from 1

– 2 years. Estimates provided by ANSP and Manufacturer sector respondents were on both sides of this range with Manufacturers on average spending less than six months on O&M

and ANSPs needing three years. As for the number of employees needed for EMS O&M, the estimates varied by sector and are as follows: five for ANSPs, 28 for Airports, 15 for Airlines, 30 for Manufacturers, and 16 for Others.

Figure 6.4: Average resource use for EMS O&M within each aviation industry sector.

6.4a

– Air Navigation Service Providers 6.4b

– Airports

O&M Resource Average

O&M time (months) 22.2 Employees used 27.7 Contractor support costs (USD) $22,577 Equipment costs (USD) $21,554 Certification / registration costs (USD) $5, 020

Note : Averages based on 54 Airport responses.

6.4c

– Airlines 6.4d

– Manufacturers

O&M Resource Average

O&M time (months) 3.8 Employees used 29.5 Contractor support costs (USD) $5,000 Equipment costs (USD) $25,000 Certification / registration costs (USD) $77,000

No te : Averages based on 8 Manufacturer

responses.

6.4e

– Others

O&M Resource Average
O&M time (months) 14.3 Employees used 16.0 Contractor support costs (USD) $63,511 Equipment costs (USD) $30,000 Certification / registration costs (USD) $6,636

Note : Averages based on 19 Other responses. O&M Resource Average

O&M time (months) 36.0 Employees used 5.0 Contractor support costs (USD) $275,000 Equipment costs (USD) $10,000 Certification / reg istration costs (USD) $36,653

Note : Averages based on 6 ANSP responses.

O&M Resource Average

O&M time (months) 17.0 Employees used 14.8 Contractor support costs (USD) $14,500 Equipment costs (USD) $36,407 Certification / registration costs (USD) $7,704

Note : Averages based on 42 Airline responses.CAEP/8

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The range of contract support costs were estimated to be $5,000

– $22,577 for three out of five sectors (Airports, Airlines, and Manufacturers). Other sector respondents estimate an average cost of $63,500 for

contr act support and ANSPs estimated an average cost of $275,000. The cost of equipment for four out of five sectors (Airports, Airlines, Manufacturers, and Others) was estimated to be between $21,000

– $36,000. Equipment costs for ANSPs were estimated to be $1 0,000 on average. Lastly, three out of five sectors (Airports, Airlines and Others) estimate average EMS certification and registration costs to be in the range of $5,000

– $7,704. Manufacturers and ANSPs had higher estimates for EMS certification and regi stration costs. Manufacturers estimated $77,000 for EMS certification and registration costs and ANSPs estimated about $37,000. Once again, it is important to note that the monetary figures provided were rough estimates and caution should be taken in usi ng the data as representative of industry or sector

trends.

Staff training is necessary for both EMS implementation and maintenance. Questionnaire respondents were asked to indicate the types of staff training required for their EMS. The training of man agement and office personnel and engineering and maintenance staff had the highest respondent percentages across all five sectors. Sector differences were apparent in the additional types of training that were required for EMS implementation and maintenan ce (Figure 6.5). For example, airlines required both ground operations personnel and cabin crew training, airports required ground operations personnel training, and manufacturers required manufacturing personnel training. Figure 6.5: Staff training requi red as a result of the EMS within each aviation industry sector.

6.5a

– Air Navigation Service Providers 6.5b

– Airports

Implementation Resource Average
Management & office staff 91% Engineering & maintenance staff 83% Manufacturing staff 1 1% Ground operations staff 39%

Air traffic controller staff 9%

Cabin crew staff 0%

Other staff 17%

Note : Percentages based on 46 Airport

responses.

6.5c

– Airlines 6.5d

– Manufacturers

Implementation Resource Average

Management & office staff 88% Engineering & maintenance staff 88% Manufacturing staff 88% Ground operations staff 38%

Air traffic controller staff 0%

Cabin crew staff 0%

Other staff 25%

Note : Percentages based on 8 Manufacturer responses. Staff Requiring EMS Training
Management & office staff 80% Engineering & maintenance staff 80% Manufacturing staff 0% Ground operat ions staff 20%

Air traffic controller staff 40%

Cabin crew staff 0%

Other staff 40%

Note : Percentages based on 5 ANSP

responses.

Implementation Resource Average
Management & office staff 84% Engineering & maintenance staff 76% Manufacturing staff 8% Ground operations staff 63%

Air traffic controller staff 8%

Cabin crew staff 45%

Other staff 47%

Note : Percentages based on 38 Airline

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6.5e

– Others

Impl ementation Resource Average
Management & office staff 29% Engineering & maintenance staff 24% Manufacturing staff 12% Ground operations staff 24%

Air traffic controller staff 0%

Cabin crew staff 6%

Other staff 12%

Note : Averages based on 17 Other

r esponses.

Chapter 7. Benefits and Challenges

7

. 1

. Introduction

While organizations differ, there are lessons

- learned from every EMS implementation. This chapter discusses and analyzes the benefits and challenges perceived by respondents to implementing EMS

. Analysis and discussion of trends has been aggregated for all sectors.

7

. 2

. Implementation Challenges

Respondents, regardless of sector, identified many of the same challenges with EMS implementation. Figure 7.1 outlines the top three challenges experience d by questionnaire respondents. The greatest challenges identified were the amount of resources and the degree of culture change necessary for successful EMS implementation. Respondents stated that it was difficult to alter employee behavior

towards inco rporating environmental considerations and responsibilities into decision making and day to day operations.

Figure 7.1: Top three EMS implementation challenges.

EMS Implementation Challenges

Resources (time, finances) 26% Culture change 26% Employee aw areness / training 23% Management commitment 16%

Note : Percentages based on 110 survey respondents.

Another common challenge respondents faced was adequately training employees to be aware of the EMS and their responsibilities with regards to system ma intenance. Lastly, lack of management commitment was cited as the third most common challenge among respondents. In addition to those included in Figure 7.1, respondents identified EMS alignment within the larger organization and recordkeeping requiremen ts during EMS implementation as further implementation challenges. It is important to note that the challenges identified above are often the most common issues with EMS implementation.CAEP/8

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7

. 3

. Benefits of EMS Implementation

The three most common benefits of EMS implementation are illustrated below in Figure 7.2. Respondents indicated that the greatest benefit of EMS implementation is that it enhances the reputation and image of the organization. In addition, respondents noted that this enhanced reputation i mproved their relationship with stakeholders. Another benefit of EMS implementation is improved compliance with environmental regulations. Also, since EMS is a proactive approach to environmental management, risk to the organization is mitigated. Lastly , respondents cited that improving the environment, or lessening their organization‘s impact on the environment, was an important benefit of EMS implementation. Other benefits of EMS implementation included the ability to track environmental performance, a reduction in costs, and an increase in awareness and efficiency.

Figure 7.2: Three most frequently cited benefits of EMS implementation.

EMS Implementation Benefits

Enhance reputation / image 34% Enhance compliance / mitigate risk 33%

Environmental i mprovements 25%

Note : Percentages based on 110 survey respondents.

7

. 4

. Trade

- off Analysis

According to the sector respondents, the benefits of EMS implementation far outweigh the implementation and maintenance challenges. Approximately 96 percent of ques tionnaire respondents recommend that other organizations establish EMS. Many respondents stated that they would be willing to share some of their EMS materials including environmental policies, environmental/sustainability reports, performance metrics, an d objectives and targets. However, organizations were not willing to share EMS documentation that may contain proprietary information such as audit reports and complete

EMS Manuals.

Chapter 8. Organizations without an EMS

8

. 1

. Introduction

Some organization s have not implemented an EMS, but do have other environmental programs in place to manage their environmental issues. This chapter discusses and analyzes responses from those organizations that have not implemented an EMS. It reviews the approaches that are used to manage environmental issues and impacts including those that are common to EMS and it analyzes the environmental issues and impacts that are most important to these organizations now. In addition, it investigates the metrics and targets that are established to measure performance and the types of guidance that would be helpful to assist them in implementing an EMS. Where applicable, the analysis and discussion investigates trends by industry sector.

8

. 2

. Environmental Program Elements or Principl es

A total of 116 questionnaire respondents do not apply EMS standards or guidelines. However, these respondents have environmental programs in place that have many of the same elements or principles required for an EMS. Respondents without a formal EMS were asked to identify whether or not EMS elements were included in their environmental program. Figure 8.1 illustrates the percentage ofCAEP/8

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respondents, by sector, whose environmental program includes certain elements or principles consistent

with EMS.

Fig ure 8.1: Environmental program elements of organizations that do not apply EMS standards or

guidelines.

8.1a

– Air Navigation Service Providers 8.1b

– Airports

Environmental Program Elements

Environmental Vision / Policy 68% Goals, Objectives or Targets 66%

M anagement Programs 58% Operational Controls 84%

Environmental Metrics 53% Performance Reporting 63% External Communication Programs 39% Employee Awareness Training Programs 61% Compliance Audits / Inspections 61% Systems / Process Audits 39% Emerge ncy Preparedness 68% Management Structure or Framework 50% Top Management Performance Reviews 34%

Note : Percentages based on 38 Airport

responses.

8.1c

– Airlines 8.1d

– Manufacturers

Environmental Program Elements

Environmental Vision / Policy 100%

Go als, Objectives or Targets 100% Management Programs 50% Operational Controls 100%

Environmental Metrics 100% Performance Reporting 100% External Communication Programs 100% Employee Awareness Training Programs 100% Compliance Audits / Inspections 10 0% Systems / Process Audits 50% Emergency Preparedness 100% Management Structure or Framework 100% Top Management Performance Reviews 50%

Note : Percentages based on 2 Manufacturer

responses. Environmental Program Elements

Environmental Vision / Policy 63% Goals, Objectives or Targets 44% Management Programs 19% Operational Controls 75%

Environmental Metrics 19% Performance Reporting 38% External Communication Programs 25% Employee Awareness Training Programs 38% Compliance Audits / Inspections 31% Systems / Process Audits 31% Emergency Preparedness 38% Management Structure or Framework 13% Top Management Performance Reviews 13%

Note : Percentages based on 16 ANSP

responses.

Environmental Program Elements

Environmental Vision / Policy 89% Goals, Objectives or Targets 74% Management Programs 51% Operational Controls 63%

Environmental Metrics 34% Performance Reporting 49% External Communication Programs 37% Employee Awareness Training Programs 57% Compliance Audits / Inspections 60%

S ystems / Process Audits 37% Emergency Preparedness 57% Management Structure or Framework 34% Top Management Performance Reviews 26%

Note : Percentages based on 35 Airline

responses.CAEP/8

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8.1e

– Others

Environmental Program Elements

Environmen tal Vision / Policy 82% Goals, Objectives or Targets 73% Management Programs 64% Operational Controls 86%

Environmental Metrics 41% Performance Reporting 64% External Communication Programs 50% Employee Awareness Training Programs 77% Compliance Au dits / Inspections 77% Systems / Process Audits 55% Emergency Preparedness 77% Management Structure or Framework 64% Top Management Performance Reviews 50%

Note : Percentages based on 22 Other responses.

It is evident from the data that respondents a cross all five sectors have many elements of an EMS in place. Respondent percentages were high across all sectors for the following elements:

 Environmental vision/policy;

 Environmental goals, objectives or targets;

 Operational controls;

 Employee awareness training programs;

 Compliance audits/inspections; and

 Emergency preparedness.

On average, top management performance reviews had the lowest respondent percentage across all five sectors. This is important to note because management commitment is imperat ive for organizations to effectively manage their environmental impacts. Organizations with an EMS indicated that management commitment is one of the biggest challenges of EMS implementation. Lastly, it is important to note that there were only two respo ndents from the manufacturing sector.

8

. 3

. Performance Monitoring

Respondents that use an environmental program rather than a formal EMS were asked to rate how helpful it is in managing and controlling 28 specific environmental issues or impacts. Figure 8.2 includes five tables that list those environmental issues most commonly identified as helpful today by respondents in each sector. Generally, there was not a strong level of agreement on the level of helpfulness across all five industry sectors.

Although there was no agreement across the aviation industry, four out of five sectors (ANSPs, Airlines, Manufacturers, and Others) agreed that their environmental programs were helpful in managing and controlling compliance with laws and regulations today. Four o ut of five sectors (ANSPs, Airports, Airlines, and Others) also agreed that their environmental program was helpful in managing customer and other stakeholder concerns, fuel efficiency, financial, and company core values and ethics. (Note: O nly two respond ents were identified as part of the manufacturer sector.)CAEP/8

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Figure 8.2: Areas of environmental concern in which use of an environmental program is seen as helpful

by organizations that do not apply EMS standards or guidelines for management.

8.2a

– Air Nav igation Service Providers

Environmental Issue or Impact Helpful Today Not Applicable High Medium

Aircraft Noise  Emissions from ground activities  Noise from ground activities  Fuel efficiency 

Financial  Compliance with laws and re gulations  State/country policies  Competitive pressures  Company core values and ethics  Media pressure  Corporate image  Local community concerns 

Non

- governmental organizations  Capacity and growth constraints 

Soil a nd water protection  International public perceptions 
Waste management  Materials and chemicals management  International policy 

Customers and other stakeholders' concerns  Shareholders appreciation or rating agencies 

Note : A reas of helpfulness determined through identification of categories with single highest respondent percentage within the ANSP sector.

8.2b

– Airports

Environmental Issue or Impact Helpful Today Helpful in 5

years Medium

Aircraft Emissions 

Noise from ground activities  Fuel efficiency 

Financial  Competitive pressures  Company core values and ethics  Media pressure  Local air quality 
Energy management  Operational efficiency 

Customers and other stakeholders' concerns 

Note : Areas of helpfulness determined through identification of categories with single highest respondent percentage within the Airport sector.CAEP/8

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8.2c

– Airlines

Environmental Issue or Impact Helpful Today High Medium

Aircraft Emissions 

Aircraft Noise  Emissions from ground activities  Noise from ground activities  Fuel efficiency 

Financial  Compliance with laws and regulations  State/country policies  Competitive pressures  Company core values and ethics  Media pressu re  Corporate image  Ecological conservation  Local community concerns  Global climate change 

Non

- governmental organizations  Corporate commitment and vision  Capacity and growth constraints  Soil and water protection 

Internati onal public perceptions 
Waste management  Materials and chemicals management  Operational efficiency  International policy 

Customers and other stakeholders' concerns 

Note : Areas of helpfulness determined through identification of categ ories with single highest respondent percentage within the Airline sector.

8.2d

– Manufacturers

Environmental Issue or Impact Helpful Today Not Applicable High Compliance with laws and regulations 

Non

- governmental organizations 

Note 1 : Areas of helpfulness determined through identification of categories with single highest respondent percentage within the Manufacturer sector.

Note 2 : Only 2 of the responses that CAEP received were from organizations that identified themselves as manufacturers without an EMS currently in place.CAEP/8

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8.2e

– Others

Environmental Issue or Impact Helpful Today High Medium

Aircraft Emissions 

Aircraft Noise  Noise from ground activities  Fuel efficiency 

Financial  Compliance with laws and regulatio ns  State/country policies  Competitive pressures  Company core values and ethics  Media pressure  Corporate image  Ecological conservation  Local community concerns  Local air quality 

Non

- governmental organizations  Capacity and growth constraints  Soil and water protection  International public perceptions 
Waste management 
Energy management  Materials and chemicals management  Operational efficiency 

Customers and other stakeholders' concerns 

Share holders appreciation or rating agencies 

Note : Areas of helpfulness determined through identification of categories with single highest respondent percentage within the Other sector.

Respondents rated each environmental issue against six levels of env ironmental program helpfulness: very helpful now, medium helpful now, likely to be helpful in 5 years, likely to be helpful in 10 years, will never be very helpful, and not applicable. Only one level of helpfulness could be assigned to each

environmental issue or impact

.

Similar to respondent organizations with an EMS, respondents without an EMS indicated that it is important to measure environmental performance to ensure compliance. In addition, respondents also indicated that it is important to minimiz e the organization‘s impact on the environment. Environmental performance is typically measured through the continuous monitoring and measurement of specific elements important to the organization. In addition, performance is also measured through yearly reviews and inspections as well as by number of incidents that occur per year. The environmental targets set by respondent organizations tend to focus on the reduction of water, fuel, energy, and waste consumption.

Respondents without a formal managemen t system were asked to list the five most important environmental regulations with which their organization‘s environmental program helps ensure compliance. As a result of having questionnaire respondents from all over the world, various environmental reg ulations were identified as important, and there was no clear consensus on specific legislation. As with the analysis performed on respondents who have an EMS in place (Section 5.1 ofCAEP/8

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this report), results were categorized into areas of environmental conc ern, which were then tallied and ranked to identify the top five areas respondents without an EMS ensure compliance (Figure 8.11)

Figure 8.11: F ive most frequently cited areas of environmental regulatory concern.

Important Environmental Regulation Areas

Hazardous/solid waste 54%

Air 49%

Water 47%

Noise 39% National environmental regulations 17%

Note : Percentages based on 87 respondents.

The five environmental areas identified as important by respondents without an EMS are identical to

those identif

ied by organizations with an EMS. The management and disposal of hazardous and solid waste is the greatest priority to organizations with and without an EMS. Second, legislation that regulates the quality and management of air emissions, in particular ca rbon dioxide was important to 49 percent of questionnaire respondents. The third most important environmental area concerns the quality, management, and use of storm water, waste water, and drinking water. Managing the level of noise was also deemed impo rtant by all five sectors. Lastly, a few respondents indicated that they ensure compliance with other types of country specific national environmental legislation.

8

. 4

. Communication Methods

Respondents were asked to identify the methods used by their organiz ation to communicate about its environmental program. As the same trends were found among all five sectors, the results were aggregated at the industry level. Figure 8.12 provides a breakdown of the communication methods used by respondent organizations with an environmental program in place, but no formal EMS framework.

Figure 8.12: Methods used by organizations across the aviation industry that have not implemented an

EMS for communicating the performance of their environmental program.

Sustainability / CSR Re ports

Websites

Newsletters

Community Meetings

OtherCAEP/8

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It is evident that all the communication methods outlined in the figure above are applied fairly consistently among the respondents. While the use of websites appears to be the most common means of communication, other methods identified include: posters and brochures, internal meetings, presentations at seminars, and email.

8

. 5

. EMS Application and Development Issues

A variety of reasons exist as to why organizations do not apply EMS standards or guidelines. According to the questionnaire‘s respondents, mos t (79 total) are planning to implement EMS in the future. Airlines (28 in total) and airports (26 in total) make up the majority of respondents who are planning to implement

EMS in the future.

The reasons why respondent organizations across the aviatio n industry do not apply EMS standards or guidelines are outlined below in Figure 8.13. The most frequent reason for not implementing an EMS is that the organization is not familiar with the EMS approach. Of the five sectors, airlines (11 in total) and

ai rports (8 in total) had the highest response rate for not being familiar with EMS approaches.

Figure 8.13: Primary reasons for not applying EMS guidelines or standards cited by organizations

within each aviation industry sector.

8.13a

– Air Navigation Service Providers 8.13b

– Airports

8.13c

– Airlines 8.13d

– ManufacturersCAEP/8

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Of the 116 respondent organizations that do not apply EMS standards or guidelines, 79 plan to implement an EMS in the future. Respondents were asked to list those environmental issues their organization would focus on if they were to implement an EMS. Fi gure 8.14 outlines the top five environmental issues in which respondent organizations would focus their organization‘s EMS.

Figure 8.14: Top five environmental issues for inclusion in future EMS.

Important Environmental Issues

Air emissions 73%

Hazard ous/solid waste 51%

Noise 50% Fuel efficiency 30% Energy 23%

Note : Percentages based on 86 respondents.

The environmental issues identified in figure 8.14 closely resemble the list of important regulated environmental areas in Figure 8.11. According to survey respondents, air emissions are the most important issue on which to focus their organization‘s EMS. Other important elements to focus on include the consumption of fuel and energy.

In order to become more familiar with EMS, respondent organiza tions have requested guidance to help assist with EMS implementation. Figure 8.15 illustrates the types of CAEP guidance requested by respondents. 8.13e

– Other

Plan to implement EMS in future

EMS not appropriate to organization

Not familiar with EMS approaches

Lack sufficient financial resources

Don't believe EMS will add value

OtherCAEP/8

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Figure 8.15: Usefulness of CAEP guidance types in assisting aviation industry organizations with EMS imple mentation.

Figure 8.15 indicates that respondents thought that all the guidance materials suggested by the questionnaire could be useful in assisting them with EMS implementation. However, the most useful type of guidance that ICAO

- CAEP could provide appears to be aviation industry EMS implementation guidance.

Chapter 9. Recommendations

The following two recommendations are based on information summarized in the report above and input from CAEP TG members. These recommendations focus on increasing awareness of EMS principles and best practices in the aviation sector and establishing practical guidance to assist those states and organizations that chose to use EMS to enhance the way they manage environmental issues. Awareness and guidance materials should integrate existing ICAO environmental tools, guidelines, and manuals. Where possible they should encourage organizations to support higher

- level ICAO environmental objectives, consider the collaborative nature of the aviation industry, and account for variance in types of organizations in the aviation sector and the level of EMS (or environmental program) maturity at the organization.

1

. Disseminate Report Information. Within the first year of the CAEP/9 cycle, disseminate the CAEP/8 EMS report info rmation to States, questionnaire respondents, and the public through various mechanisms (e.g., State letter, Assembly resolution language promoting EMS and/or principles, website, workshop, presentation).

2

. Develop EMS Guidance

. Stand alone EMS guidance should be developed for the end of the CAEP/9 cycle. This should assist organizations to determine how EMS elements and principles can be used to enhance the way they manage environmental issues and provide practical guidance on how these

EMS elements and principles can be implemented/integrated into existing management systems and business processes. General EMS guidance

Aviation industry EMS implementation guidance

Aviation industry EMS guidance on important

focus areas

Aviation industry EMS best practice & guidan ce repository

No guidance necessary

OtherCAEP/8

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Chapter 10. Conclusion

In February 2007, the TG was assigned a project for the CAEP/8 work program to deliver a report providing information on the use of EMS and, as appropriate, make recommendations on how the committee could promote the use of EMS within the aviation system. As a result, the TG developed an industry questionnaire to learn more about the application and potential value of EMS to aviat ion organizations. A total of 233 responses from air navigation service providers, airlines, airports, and manufacturers formed the basis of this report and supported the development of recommendations.

Approximately 50 percent of questionnaire responden ts (a total of 117) apply EMS standards or guidelines, with the majority having an ISO

- 14001 v2004 certified EMS in place. The remaining 116 respondents that have other environmental programs in place have many of the same principles and practices that ar e required as part of a formal EMS. For those organizations with an EMS, 82 percent have additional management systems in place

— approximately 51 percent of these additional systems are integrated or coordinated with the organization‘s EMS. Over the past ten years, EMS implementation has been relatively consistent in the aviation industry. On average, respondents indicated that 6

- 12 months are needed to successfully develop and implement an EMS. Approximately 71 percent of organizations had

assistance wit h EMS implementation from a consulting or contracting firm. Respondents indicated that the three most common benefits of EMS implementation are enhanced reputation or image, enhanced compliance and mitigation of risk, and environmental improvements.

Rega rdless of whether the respondent organization had an EMS in place, measuring environmental performance is important for ensuring compliance. On average, the majority of questionnaire respondents communicate environmental performance through a corporate so cial responsibility report or through their organization‘s website. Environmental areas of regulatory concern were primarily a focus of organizations regardless of whether or not they implemented an EMS. 79 respondent organizations without an EMS plan to implement one in the future. These organizations indicated that the most common reason for not implementing an EMS was unfamiliarity with EMS approaches. As a result, aviation industry specific EMS implementation guidance was requested by these organi zations.

Recommendations were made on how ICAO

- CAEP could promote the use of EMS within the aviation industry based on questionnaire results. The recommendations were to disseminate the CAEP/8 EMS report information to States, questionnaire respondents, and the public through various mechanisms, and consider development of EMS guidance. Any guidance should consider t he collaborative nature of the aviation industry. This report is disseminated to States, questionnaire respondents, and the public in order to further increase awareness of EMS principles and best practices in the aviation sector.CAEP/8

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References

International Civil Aviation Organization. Assembly Resolutions in Force (as of 28 September 2007). September 2007. http://www.icao.int/icaone1t/dcs/9902/9902_en.pdf

International Civil Aviation Organization. Environmental Issues Related To Implementation of CNS/ATM System . CNS/MET

- ATM

- IP/33. July 2003

International Civil Aviation Organization, Committee on Aviation Environmental Protection. Environmental Management Systems . CAEP/7

- WP/54. February 2007

International Civil Aviation Organization. ICAO Environmental Report 2007 . 2007. http://www.icao.int/env/pubs/Env_Report_07.pdf

International Civil Aviation Organization, Committee on Aviation Environmental Protection. Update on Environmental Management System (EMS) Task . CAEP8_WG2_LUPTG2_WP03. October 2007

In ternational Organization for Standardization. ISO 14001 Environmental management systems

— Requirements with guidance for use, November 2004 (2 nd edition).

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