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ICAO COMMITTEE ON AVIATION ENVIRONMENTAL PROTECTION

WORKING GROUP 3 - EMISSIONS TECHNICAL

6th Meeting

1 - 3 April 2009

London, UK

Draft Report of 6th Meeting

Plenary Sessions

Presented by Rapporteurs

1 Welcome

Curtis Holsclaw, Co-Rapporteur of WG3 took the chair and welcomed members and guests 

to the fifth meeting under the CAEP8 work programme. New members were Marcelo Saito 

(ANAC, Brasil) who attended with Cesar Hess and will be replacing him in future meetings 

and Mr Matthew Spears (EPA, USA)

2 Administration

2a Attachment A to this report lists the attendees. The current membership list [IP6-01] 

was circulated for attendance recordkeeping and amendment as necessary.

2b The Rapporteurs reviewed the schedule [WP6-01], noting the initial Plenary was 

intended to handle the bulk of the working group activities and that the mini-Plenary 

sessions following each of the Task Group [TG] meetings would be held to handle 

any WG3-level business related to outcomes of those task group meetings.

2c The meeting approved the Agenda [WP6-02]. 

2d Attachment B to this report and IP6-02 provide a complete list of papers. 

Attachment C lists the actions resulting from this meeting.

Attachment D and FL6-03 provides the initial response to GIACC/3 requests

3 Fifth Meeting of WG3 (November 2009,Tokyo, Japan)

3a Approval of Minutes

The draft report of the fifth meeting of WG3 in Tokyo [WP6-03] had been circulated and a 

number of comments received. The substantive ones were:

Section 8.4: Delete paragraphs 8.4.1 & 8.4.2

Section 8.7: Need to harmonise the wording relating to a CO2 standard with the 

amendment noted earlier in section 3.1 of WP6-03 relating to the minutes of the 

Montreal meeting [WP5-03], ie that the text regarding a ‘CO2 standard’ is not to be 

interpreted as an aviation CO2 certification standard
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The meeting accepted the proposed changes together with the minor editorial revisions 

throughout the paper and approved the final version. 

3b Actions & Matters arising 

3.1 All actions listed in Attachment C to WP6-03 had been completed, with the exception of 

action 5.4 which would be addressed by CTG during this meeting.

3.2 It was noted that ICCAIA had developed three NOx scenarios and provided them to 

MODTF in late 2008 for use for Environmental Goals modelling purposes. Although LTTG 

had accepted them during the course of scheduled Ad-hoc telecon discussions and further 

discussed them in Tokyo, WG3 had not formally accepted them. WP6-17 sets out the 

details and a number of recommendations on how MODTF should implement these 

scenarios. WG3 accepted this document for the record.

3.3 In addition, two other more extreme scenarios had been proposed by government 

members of WG3 and passed to MODTF for use.

3.4 The feedback from MODTF was that all these proposals were easy to implement, but 

queried why, in the ‘government’ scenarios’, when there was a high fuel improvement 

factor, there was no NOx improvement. 

3.5 In discussion, it was suggested that since these government’ scenarios assumed the 

realisation of all research goals, then there should be both a fuel and NOx improvement 

factor applied and proposed that the ICCAIA best NOx factor should be taken. ICCAIA 

stressed that these scenarios were not supported by industry and that it was up to the 

members who made the proposals to decide the response. It was agreed that the 

government representatives would discuss this and report back to the group by the end of 

the week.

Action 6.1: Convene group to review NOx improvement factors to be applied in ‘government’ 

scenarios and to report back to WG3 by Friday. [CJE]

3.6 The outcome of this further discussion was presented in FL6-01. The recommendations 

were that, WG3 should:

i) note that ICCAIA retain their position that fuel and NOx technology scenarios should 

be limited to the technology improvements previously recommended by ICCAIA.

ii) note that the WG3 members associated with the “Government” scenario 

recommend the NOx scenario associated with the “advanced” technology scenario 

also be used for the “Government” scenario

iii) pass the recommendation in (ii) to MODTF

 .

WG3 accepted these recommendations.

Action 6.2: To pass the recommendation (ii) on NOx improvement factors on to MODTF. [CJE]

4 Requests from the Third Meeting of GIACC [WP6-09 (App A), WP6-10, WP6-11, WP6-

17, IP6-07]

4.1 The CAEP Secretariat presented the WP6-09 part that related to the GIACC/3 meeting. 

Section 2 reviewed the meeting and Appendix A provided the Summary of Tasks requested 

from GIACC/3 to CAEP. WG3 was requested to consider the items requested from 

GIACC/3 to CAEP in paragraph 2.3 and 2.4 and in the Appendix A, in particular the item 2, 

3 and 5 of the Appendix A for CAEP WG3, in order to prepare the initial view and 
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necessary deliverables of CAEP WG3 for these items (e.g. related issues, challenges and 

work plan for CAEP/9 cycle), in time for GIACC/4 meeting on 25-27 May 2009.

4.2 In clarification, it was pointed out that the 1st column of Appendix A was the specific request 

as developed by GIACC/3. The 2nd column was the ‘initial interpretation’ by the CAEP 

Secretary that had been re-presented to GIACC/3 and accepted by them. WG3 was also 

free to add its interpretation of the requests and its response would be taken into 

discussion at the Steering Group in June 2009. CAEP had not yet accepted the requests -

they would essentially be CAEP/9 work items.

4.3 The three specific requests are considered further below.

4a. Efficiency metric that takes into account alternative fuels

4.4 Discussion on this topic was deferred to Agenda item 9f (Report of the Fuel Efficiency 

Metric [FEM] ad-hoc group).

4b Fuel conversion factors between existing fuels and potential biofuels

4.5 A number of the considerations were also part of the FEM discussions. If this was primarily 

aimed at assessing life cycle differences then it was not a WG3 activity. Sources outside of 

CAEP such as CAAFI, SWAFEA were already addressing these. However, if it was 

requesting CO2 emissions factors then this simply required knowledge of the fuel 

composition; it was pointed out that while the CO2 may be the same, the HC composition 

might be significantly different and that would be an issue for WG3.

4c The question of setting a CO2 standard [WP6-10, WP6-11, IP6-07]

4.6 WP6-10 presented by ICSA reviewed options for a carbon intensity metric for new aircraft. 

Any useful metric should recognise and reward technical progress and could be different 

for different functions eg freight (mass) or passengers (numbers). The preferred options 

were for an ATK /ASK basis, arguing that a TOW base did not distinguish between fuel 

burnt (a) to move the airframe weight (b) to carry fuel and (c) to move payload. The paper 

also proposed that the diversity of function for various aircraft could be handled either by 

setting separate standards for different aircraft types, or by establishing a sales and 

activity-weighted intensity target for individual manufacturers. Given sufficient priority by 

WG3, it was believed that a suitable metric could be developed in time to recommend an 

airframe CO2 standard within the CAEP/9 work cycle.

4.7 ICCAIA acknowledged the high level of technical understanding by ICSA and agreed that 

development of a CO2 standard had more chance of success if it was focussed on new 

aircraft types rather than on in-service ones. No comment was offered on the metric 

proposals at this time.

4.8 In discussion the following points were raised:

 All metrics are, to some degree, imperfect. We need the best metric we can find, for which 

any perverse consequences are small in CO2 terms. Also the change in the political 

climate gave opportunities to reconsider previous thinking.

 There was need for consistency between freight and passenger. Conversion factors for 

passenger weights vary. It was noted that any metric has a specific use and couldn’t 

necessarily be applied across the board.
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 There would be need for a body of documentation to underpin any decision in CAEP/9

 Care needed to be taken that both policy and technical perspectives are considered 

appropriately.

4.9 Following this the Rapporteurs proposed that further discussion of this should be remitted 

to CTG. The group accepted this recommendation.

Action 6.3: To consider the ICSA proposals in scoping the work required to develop a CO2

standard [CTG]

4.10 WP6-11 from ICCAIA addressed issues arising from an earlier FAA proposal [Nov 2008] 

that “given the previous difficulties in developing a sophisticated parameter and scheme for 

the whole aircraft .......there may be options to consider that focus solely on the engine in a 

similar manner as the current LTO cycle gaseous emissions standards... “. At that 

meeting, ICCAIA stated “An engine based standard would be detrimental or counter 

productive to improved aircraft performance. Also previous WG3 work on alternative 

emissions methods, during CAEP5 and CAEP6 had already pointed out potential adverse 

consequences from an engine based standard” 

4.11 ICCAIA had considered the specific suggestion to base an efficiency parameter solely on 

the engine, and the suggestion to use LTO data for an efficiency parameter, in terms of 

CO2 emissions. It was concluded that an engine-only based efficiency parameter was 

unlikely to be a fair and useful means to judge the relative merits of different products. A 

poorly defined efficiency parameter could influence manufacturers to optimize designs to 

unrealistic requirements. Additionally, thrust and fuel flow rate data from ICAO emissions 

certification tests at sea level static conditions were not representative of in-service 

efficiency over a full flight cycle. ICCAIA asked for WG3 endorsement of these 

conclusions.

4.12 There was support for the view that a CO2 standard should be aircraft based, but the UK 

suggested that if there were no prospect of this then an alternative approach would be 

needed. It was stated that LTO fuel / thrust was clearly not appropriate, but possibly some 

factoring of these for flight conditions might be considered. ICCAIA pointed out that the 

complexity of the factoring would make this extremely difficult.

4.13. In response to a comment that LTO fuel was reasonable for characterising block fuel for 

RJs, even if not for large wide body aircraft, it was noted that the trades would vary with 

aircraft sizes.

4.14 IP6-07 provided a Collection of past CAEP material on CO2 Standard and Aircraft Efficiency 

Parameters

4.15 WG3 accepted the conclusions presented in WP6-11.

4.16 The Rapporteurs reminded the meeting that WP6-09 had requested WG3 to consider the 

items requested from GIACC/3 to CAEP in paragraph 2.3 and 2.4 and in the Appendix A, in 

particular the item 2, 3 and 5 of the Appendix A and prepare the initial view and necessary 

deliverables of CAEP WG3 for these items, in time for GIACC/4 meeting on 25-27 May 

2009. This would need input from CTG and the FEM ad-hoc group.

Action 6.4: Develop the initial response on GIACC/3 requests and report back to WG3 by

Friday for approval. [Rapporteurs]
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4.17 A draft of this response was further discussed /amended at the end of the meeting and the 

final version is given in Appendix D to this report [also as FL6-03].

Action 6.5: Forward initial response of WG3 to GIACC/3 requests to CAEP Secretariat by end 

of April [Rapporteurs]

5 Reports from LTTG [WP6-04, WP6-05, WP6-06, IP6-03]

5a IE Initial report on Fuel Burn Reduction Technology Workshop [WP6-04, 

WP6-05]

5.1 The ICCAIA led Workshop had taken place in the previous week. The FBRT Independent 

Experts (IEs) had prepared an initial paper (presented by LTTG lead in absence of IE 

Chairman). 

5.2 In summary, the IEs noted that the Workshop represented a good start for their task to 

discharge the SG remit to provide technology goals for fuel burn reductions over a 10 and 

20-year timeframe. However, in their view:

 the Industry 20 year technology projections were weak

 few technologies discussed were at a low TRL and therefore there appeared little 

continuity between near medium and long term technologies

 there was no indication of probability of success

 the EC presentation on European research projects offered no substantive information 

on LT technology goals 

In general, more (quantified) information was needed and therefore the IEs could not offer 

views on precise quantitative goals at this stage, but it should be possible to indicate broad 

regions for long term technology goals (using uncertainty bands) for an agreed range of 

different aircraft classes

The IEs will be preparing a report for presentation at the SG meeting in Brazil, June 2009, 

with recommendations relating to a formal technology review for fuel burn reductions in 

2010.

5.3 In response ICCAIA was strongly of the opinion that the IEs had treated the Workshop as if 

it was the Review; their expressed views did not appear to match what ICCAIA believe they 

had offered. There was a need for urgent interaction to address any differences of 

expectations. Also, ICCAIA was unsure whether there was an adequate spread of 

expertise among the IEs. ICCAIA noted that it would not be easy to provide all the data 

requested owing to its commercially sensitive nature and that this would be unlikely to 

change in the near future.

5.4 WG3 noted the initial report from the IEs and the concerns expressed by ICCAIA and 

recommended that ICCAIA interact with the IEs promptly to find ways of addressing these 

issues. WG3 asked that the IEs provide a more formal paper within 2 weeks.

Action 6.6 FBRT IEs to provide written paper to WG3 on Workshop [LTTG Lead]

Action 6.7 ICCAIA to interact with IE group to address data concerns and expectations

5b IE Initial report on the NOx Emissions Technology Goals Review / update

[WP6-06]
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5.5 The Independent Expert (IE) NOx goals update review took place in the 2 days prior to 

WG3 and as such only a very simple verbal overview statement was available (presented 

by LTTG lead in absence of IE Chairman). In summary, the IEs:

 had considered all inputs, capturing the time scales for reporting to CAEP/8

 had reviewed progress towards the goals set 3 years ago; 

 reviewed the status of science understanding - believing that there was even more 

compelling need for control of NOx than appeared evident 3 years ago.

 thought that within a year the goal as defined in 2006 would be attained

 thought that there was a need to monitor the relationship between LTO NOx and cruise 

NOx

 expressed appreciation to ICCAIA for the excellent input.

 Would put further questions directly to ICCAIA and RFP/SFPs.

At the last review the IEs indicated that a goal is reached when one or more products cross 

the goal line. The IEs feel that a refinement to that assumption may be warranted, as it may 

not adequately cover engine families.

5.6 WG3 accepted this brief report and requested that the IEs provide a written paper within 2 

weeks.

Action 6.8 NOx IEs to provide written paper to WG3 on Goals review / update [LTTG Lead]

5c Fuel Consumption Scenarios [IP6-03]

At the WG3/LTTG meeting in Nov 2009, ICCAIA had presented a paper on 2 scenarios of 

new and in-production aircraft fuel burn improvement over time, to go with “Scenario 1” 

from the 1999 IPCC Special Report On Aviation And The Environment. 

As an interim status to the Fuel Burn Technology Goals Review Process, that paper 

summarized the on-going industry technology developments, which were being transitioned 

in the near future to upcoming products or were being studied for next-generation aircraft, 

in support of the fuel burn scenarios identified for the MODTF exercise.

IP6-03 by ICCAIA provided further background information on how the two new fuel 

consumption scenarios were developed.

6 Reports from CETG (WG3 Plenary and Mini Plenary) [WP6-07, WP6-18, WP6-19]

6.1 Plenary [WP6-07]

6.1.1 The CETG Leader reported on progress to date on its assigned remits.

E.05.1.a) Evaluate and document non-volatile PM measurement procedures, which, if appropriate, 

could be used in a certification methodology. DONE – draft AIR 5892 from E-31 up for vote 

late 2008/early 2009.

E.05.1.b) Develop measurement and sampling techniques for volatile PM emissions. No longer a 

deliverable for CAEP8. 

E.05.1.c) Validate and improve FOA methodology. Ongoing with PM ad hoc group. 

E.05.2 Further characterize LTO PM emissions reflecting state-of-the-science. Initial draft delivered 

this meeting from RFP/SFPs. 

E.05.3 Monitor latest understanding of PM impacts on both LAQ & climate change. Initial draft 

delivered this meeting from RFP/SFPs. 

E.05.4 Assess the data required for environmental impact studies of aircraft particle emission on 

the upper atmosphere and provide data (e.g., emissions factors), including uncertainties, for 

global emissions inventories of particles based upon ground-based and other measurement 

data. Initial draft delivered this meeting from RFP/SFPs. 
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E.08.4 APU emissions. Ongoing with Emissions Methodology ad hoc group. 

E.09.1 Review trends in aviation kerosene fuel supply composition. Ongoing with ICCAIA. 

E.09.2 Promote improved understanding of the potential use and emission effects of alternative 

fuels. Ongoing with ICCAIA/IATA. 

E.09.3 Work with CRC, ASTM, and other appropriate bodies to further evaluate the costs and 

benefits of a potential policy to remove sulphur from jet fuel. Ongoing with ICCAIA/IATA. 

E.10 Support WG2/TG4 with emissions methodologies for ICAO/CAEP Airport Air Quality 

Guidance Manual. Ongoing with Emissions Methodology ad hoc group. 

E.11 Support MODTF as requested. Ongoing on an as needed basis. 

Most of the remit items have been progressed via ad-hoc groups’ telecons and would be 

discussed further at this meeting. WG3 noted the progress to date. 

6.2 Mini-Plenary [WP6-18, WP6-19]

CETG raised 3 items to WG3 for consideration / approval as follows:

a. Emissions vs thrust relationship for airport inventory work [WP6-18]

6.2.1 WG2/TG4 had requested guidance from WG3 “whether a linear fit between the 85% and 

30% ICAO thrust setting modes is the best method for estimating emissions indices”. The 

CETG has concluded work on this as documented by CETG6 WP05 [taken as WP6-18 in 

WG3]. For thrusts down to 60%, the recommendation was to use a twin quadratic to 

estimate fuel flow from thrust, followed by the use of existing methods to estimate 

emissions from fuel flow. This advice was applicable for the purposes of calculating aircraft 

emissions inventories. CETG also requested that WG2-TG4 adhered to the precise 

language without further methodological embellishments.

WG3 approved the outcome of the work and agreed to transmit this to WG2/TG4, for 

inclusion in the ICAO Airport Air Quality Guidance document

Action 6.9: Provide WG2 TG4 with the guidance material on emissions versus thrust relationship, 

including the language caveats, as provided in Appendix A to CETG6 WP05 [WG3-WP6-18] 

for inclusion in the ICAO Airport Air Quality Guidance Manual. [Rapporteurs]

b. Guidelines For Including Effects Of Ambient Conditions And Forward Air Speed In 

Emissions Calculations Using Advanced Modelling Methods [WP6-19]

6.2.2 Preliminary guidance on such effects had already been produced by ICCAIA and included 

in the ICAO Air Quality Guidance Manual. However, this guidance was based upon the

‘Simple’ approach. WG2 has also requested a statement providing some guidance for 

modellers who wish to use an ‘Advanced’ approach. The CETG has concluded work on 

this, as documented by CETG6 WP07 [taken as WP6-19 in WG3]. This paper discussed 

how corrections for ambient conditions and forward speed effects might be applied to 

calculation methods for aircraft emissions categorized as Advanced according to the WG2 

draft guidance on airport air quality calculations. General considerations that apply to all 

Advanced models were discussed, and then Advanced Options B and A were considered 

individually. Advanced Option B was conceptually easier to adjust for these effects than 

Advanced Option A, because the performance models that underlie Advanced Option B 

should already be capable of considering them. CETG recommended the preferred use of 

option B and also laid out some important caveats for modellers using any Advanced 

method.
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WG3 approved the outcome of the work and agreed to transmit this to WG2/TG4, for 

inclusion in the ICAO Airport Air Quality Guidance document

Action 6.10: Provide WG2 TG4 with “Guidelines For Including Effects Of Ambient Conditions And 

Forward Air Speed In Emissions Calculations Using Advanced Modelling Methods” as 

provided in CETG6 WP07 [WG3-WP6-19] for inclusion in the ICAO Airport Air Quality 

Guidance Manual. [Rapporteurs]

c. Remit item E.09.1: Fuel composition and emissions effects; review trends in aviation 

kerosene supply composition.

6.2.3 A Status report on this item is a deliverable for SG2009. However, in view of other priority 

work, ICCAIA had asked that this be deferred to CAEP/8. WG3 accepted this request.

Action 6.11 WG3 report to SG2009 to reflect approval of ICCAIA request to defer delivery of 

remit item E.09.1 report until CAEP/8 [Rapporteurs]

7 Reports from CTG (WG3 Plenary and Mini Plenary)

[WP6-08, WP6-14, WP6-15; WP6-16 & WP6-20]

7.1 Plenary [WP6-08, WP6-14, WP6-15; WP6-16]

7.1.1 The CTG Leader reported on progress to date on its assigned remits [WP6-08]. 

E.03.2 Technology Interdependencies: Completed

E.06 Annex 16, Volume II: Proposals for amendments nearing completion 

E.07 Environmental Technical Manual: Proposals for updates nearing completion

E.08.1 NOx LTO stringency: Completed - further work now with FESG and MODTF

E.08.2 NOx cruise climb methodology: Now considered as a CAEP/9 future work item

E.08.3 Supersonic aircraft emissions: No significant developments - waiting on WG1

E.12 ICAO Aircraft Engine Emissions Databank: V16 issued in Feb 2009

Most of the remit items have been progressed via the ad-hoc group’s telecons and would 

be discussed further at this meeting. WG3 noted the progress to date.

7.1.2 The EPA presented 3 papers [WP6-14, WP6-15; WP6-16] that were within the scope of 

CTG and had not yet been brought to the attention of the group. Since this was also an 

issue of ‘process’ the Rapporteur stated that while an outline of the papers could be given 

to WG3, they would need to be remitted to CTG for fuller consideration before any

recommendations could be taken by WG3.

7.1.3 WP6-14 on Production cut-off, made several recommendations related to this topic. The 

Rapporteur noted that this was a policy issue already under consideration within SG and 

WG3 was not the arena for discussion until SG had given direction on it. The Rapporteurs 

suggested that the EPA re-present this paper to the SG. Also that WG3, in its report to 

SG2009, could note that it had had sight of this document and noted the policy perspective 

in it. This was accepted.

7.1.4 WP6-15 made many detailed proposals for additions to the emissions Databank. This was 

remitted to CTG for consideration.

Action 6.12: Consider proposals of WP6-15 and report back to WG3 [CTG]

7.1.5 WP6-16 on revision of exemptions provisions within Annex 16 Vol. II, attempted to address 

a number of questions that had arisen during the CTG ETM ad-hoc group discussions and 

made specific recommendations for revision of the exemption language of the Annex. It 
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was acknowledged that there was a strong link between introduction of a production cut-off 

and the need for some exemption provisions. A Rapporteur noted, however, that work on 

this topic did not imply any decision about a production cut-off.

7.1.6 ICCAIA stated that any data used in such analyses should be the latest from the 

manufacturer and, if necessary, requested between WG3 meetings. EPA believed it could 

work with ICCAIA concerns and stated that WP6-14 was aiming to open a continuing 

dialogue for mutual benefit. EPA also clarified that the data used was just related to engine 

types, not taking the proportions of flights into account.

7.1.7 FL6-02 was an initial informal response from ICCAIA to WP6-14 & WP6-16 from EPA. 

ICCAIA appreciated that the USEPA were once again directly involved in and actively 

contributing to the CAEP process. ICCAIA believed that the available evidence supported 

the view that market forces were effective and that manufacturers voluntarily complied with 

new CAEP NOx standards. ICCAIA recommended that work towards production cut-off 

provisions for any future CAEP8 standard was premature before CAEP/8. However 

ICCAIA supported work to include suitable exemption text and guidance in Annex 16 and 

the ETM and recommended that WG3 support the inclusion of this work in the future work 

programme.

7.1.8 Following these comments and clarification these papers were remitted to CTG for 

consideration.

Action 6.13: Consider proposals of WP6-16 & comments in FL6-02 and report back to WG3 

[CTG]

7.2 Mini-Plenary [WP6-20]

CTG raised 4 items to WG3 for consideration / approval as follows:

a. Estimation of PM Emissions from CIS-Manufactured Engines [WP6-20]

7.2.1 At the request of MODTF, CTG had carried out a qualitative assessment of noise and 

emissions from CIS aircraft. At CTG (Nov 2009), it was concluded that “CIS operations 

comprised a small representation of total noise and emissions, although this did vary 

across different ICAO regions. There was some discussion as to whether PM emissions 

from CIS aircraft would be disproportionately high due to higher smoke numbers.

7.2.2 This paper presented the analysis of CIS engine PM emissions as calculated from data in 

the ICAO Emissions Databank V16a (EDB). Data from the FOI database were not used 

explicitly. However, data on two CIS-manufactured turboprops were also analysed. 

7.2.3 CTG recommended that “For the purposes of supporting the CAEP/8 MODTF 

Environmental Goals Analysis, based on an approximate assessment based on in-service 

engines in the EDB and using FOA3, the estimated PM emissions from CIS- manufactured 

engines are likely to be approximately 3 to 4 times those of equivalent non-CIS engine 

types for the current fleet. For future fleets, it can be expected that next generation CIS 

types will produce similar smoke and levels to Western types. Total PM emissions will be 

subject to any fuel sulphur content differences.”

7.2.4 WG3 approved the outcome of the work and agreed to transmit this to MODTF for use in 

CAEP/8 Environmental Goals Analysis.
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Action 6.14 Provide MODTF with the information on the Estimation of PM Emissions from CISManufactured Engines contained in CTG6-WP03 (WG3-WP6-20). [Rapporteurs]

b. CO2 scoping study

7.2.5 Based on discussions held during the WG3 Plenary meeting, and subsequent input from 

relevant stakeholders, CTG proposed a way forward on the issue of developing a potential 

aircraft CO2 emissions certification requirement. CTG recommended that the SG2009 

meeting should be provided with references to past CAEP work regarding CO2 standards 

and aircraft efficiency parameters, the WG3 responses to GIACC-4 and a proposal for a 

new WG3 work item to scope out this issue in order to inform CAEP/8 discussions and any 

CAEP/9 work. The scoping work could include a comparison with existing Annex 16 Vol. II 

requirements, as well as CO2 standards in other sectors, in order to inform future workload, 

metric(s), methodology, applicability and terminology. If the study is agreed by SG2009, 

WG3/CTG recommended that WG3 establish a “CO2” ad-hoc group to address this issue 

via telecons prior to the next WG3 meeting.

WG3 accepted the proposal and agreed to bring it to the attention of SG2009.

Action 6.15: WG3 report to SG2009 to include offer of carrying out a scoping study for CAEP/8 

on the likely work required to develop a potential aircraft CO2 emissions certification 

requirement. [Rapporteurs]

c. Amendments to Annex 16, Volume II and updates to emissions ETM

7.2.6 Final agreements on the Annex 16 Vol. II issues, which had already been resolved, had 

been reached at the last meeting. As no comments had since been received from WG3 

these were now considered approved.

7.2.7 Two new items had been added to the Annex 16 ad-hoc group remit. The first was to 

review the Annex 16 humidity measurement requirements which were stricter than those 

used for performance measurements. This had already caused difficulties in past engine 

projects. The second item was linked to the ongoing discussions on a potential CAEP/6 

production cut-off requirement, and the need to review paragraph 2.1.1 of the Annex 

dealing with exemptions. Guidance on evaluating and issuing exemptions was also urgently 

required within the ETM. In the light of this, WG3 WP6-16 from the EPA had been remitted 

to the ad-hoc group for further discussion.

7.2.8 The latest updates to the ETM had been approved by CTG and were available as 

Attachment 1 to CTG-WP6/06. WG3 members were requested to provide any comments 

by Friday 22nd May.

Action 6.16: Provide comments on latest updates of ETM as provided in CTG WP6/06 by May 

22. [All WG3 members]

d. Response re EPA WP6-15 [Databank]

7.2.9 A CTG Databank ad-hoc group has been created to address the outstanding issues and to 

try to incorporate as many of these changes as possible into the next version of EDB -

likely Feb 2010.

8 Follow-on from the CAEP Impacts Workshop [IP6-04]

8.1 IP6-04 was a spreadsheet, compiled by the CAEP Secretariat, of recommendations arising 

from this Workshop, together with a request for each CAEP WG or TF to identify the level 
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of resources needed to address each of the recommendations at 3 different ‘Tier’ levels [1-

3 in increasing complexity and time scales]. The CAEP Secretariat was asking for a ‘fast 

track’ response as a SG2009 input.

8.2 There was a broad discussion about this request, including the purpose of such a matrix, 

what could be considered and the linkage of emissions to impacts, recognising that this 

could require WG3 to expand its range of expertise considerably.

8.3 WG3 agreed that an initial response would be identified by a small group of volunteers 

during this meeting.

Action 6.17: Develop an initial response to request related to follow-on from CAEP Impacts 

Workshop and report back during this meeting [Ad Hoc group (DL, MG, PM and RI)]

8.4 The initial response recommended setting up a new group (an Impacts Task Force) within 

the CAEP framework. WG3 accepted this.

Action 6.18: Pass recommendation on formation of an ITF to co-ordinators of the Workshop for 

inclusion in their submission to SG2009. [Rapporteurs]

9 Co-ordination with Other Working Groups, etc.

9.1 Technology Interdependencies Group (TIG)

There was nothing to report.

9.2 Working Group 1

CTG Lead will circulate papers from the WG1 Supersonic Task Group (SSTG) meeting to 

be held in Paris during April to CTG members. The CAEP Secretariat noted that they have 

received questions regarding the current status of the certification requirements for engines 

intended for propulsion at supersonic speeds. There was a request for a progress report 

on the IE Noise Technology Review.

Action 6.19: Request a progress report of the WG1 IE Noise Technology Review to assist WG3 

FBRT IEs [LTTG Lead]

9.3 Working Group 2

There was nothing from WG2. However an early copy of the ATM IE report would be 

helpful for WG3 FBRT IEs.

Action 6.20: Request an early copy of the WG2 ATM IE report to assist WG3 FBRT IEs [LTTG 

Lead]

9.4 Modelling and Database Task Force (MODTF)

MODTF is currently performing a second round of modelling. All WG3 stringency options 

have been used satisfactorily. Environmental Goals issues related to technology 

improvement factors have been brought to WG3 and resolved [see Section 3.6].

9.5 Forecasting and Economic Analysis Sub-Group (FESG)

There was nothing to report.

9.6 Fuel Efficiency Metric [WP6-13, IP6-08]

9.6.1 The Fuel Efficiency Metric ad-hoc (FEMah) group had been established jointly by WG3, 

WG2 and MODTF, to address task E.03.b “formulate appropriate fuel efficiency metric(s) 
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for use in assessment of CAEP Environmental goals (MODTF), air traffic operational goals 

(WG2) and aircraft and engine technology goals (WG3)”.

9.6.2 IP6-08 covered the metric for the Environmental Goals assessments only, describing the 

approach taken by the ad hoc group, the metric developed, the rationale for its creation and 

the testing undertaken. The outcome of this was the “Commercial Aircraft System Fuel 

Efficiency (CASFE)” metric (using fuel mass as the numerator and payload multiplied by 

distance as the denominator) that reflected that the metric incorporated the fleet usage and 

operational factors alongside actual aircraft performance capability.

9.6.3 WP6-13 covered overall progress on task E.03.b and the two issues raised at the Sept 08 

Steering Group (Alternative fuels and metric proposed to GIACC). In addition the paper 

made proposals to address the fuel efficiency requests from GIACC/3 to CAEP. The 

recommendations to WG3 are listed below:

a) Note the clarification to the payload-weight term shown (Section 2.1)

b) Note the potential applicability of CAFSE to the draft Operations Goals (Section 2.2)

c) Note the future work to complete Task E03b (Sections 2.1, 2.2 and 2.3)

d) Accept the proposed responses to SG Salvador on the two fuel efficiency metric questions 

from SG Seattle (Section 3)

e) Note the initial FEMah comments on GIACC/3 requests to CAEP (Section 4) and agree a 

way forward.

9.6.4 Regarding the passenger weight issue it was noted that this only refers to the ‘usefully 

moved weight’ of the person, not including anything else. The actual weight is currently 

under review [91 to 100kg]. Additionally there is also the passenger / freight weight 

conversion term. These are not items for WG3 to resolve.

9.6.5 The ad-hoc group recognised that metrics were required for different purposes and that the 

CASFE fuel efficiency metric had the potential to be adapted or extended for other 

purposes, potentially including alternative fuels. However, the CASFE metric could not be 

easily extended to radically different aircraft designs resulting from use of fuels very 

different from current aviation kerosene.

9.6.6 It was confirmed that the GIACC metric was identical in technical format to the proposed 

CASFE metric and that the application was on a fleet-wide basis, albeit at National rather 

than Global/Regional level. However, the proposed use was outside the current scope of 

the work of the FEMah Group.

9.6.7 WG3 accepted the recommendations and proposed that the information should be provided 

as a WP to SG2009, additional to the main WG3 report.

Action 6:21: Prepare paper on Fuel Efficiency Metric issues for SG2009 [FEMah group]

10 Other WG3 Business [WP6-09, WP6-12, IP6-05, IP6-06]

a. Update on environmental activities in ICAO and other UN bodies [WP6-09]

10.1 The key issues for WG3 action, namely response to GIACC/3, had already been covered in 

Agenda Item 3 [see paragraph 4.17 and App D]. 

10.2 WG3 noted the future ICAO Conference on Aviation Alternative Fuels [Nov 2009] and 

outcome of the UNFCCC COP14 [Nov 2008]. Although aviation was not the main item on 

the agenda of COP, an important development of the Conference had been the publication 

of the National Greenhouse Gas Inventory data for the period 1990–2006 which reflected, 
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inter alia, that international aviation emissions increased by 65.9 per cent in Annex I 

countries. For maritime the growth was reported to be 18.4 per cent. [IEA data based on 

fuel sales also supported this - 70% for aviation and 30% for marine] 

b. Open Rotor Technology [WP6-12, IP6-05, IP6-06]

10.3 WP6-12, supported by IP6-05 and IP6-06, were ICCAIA papers requesting work on 

emissions regulations for Open rotors and setting out potential issues associated with the 

emissions certification of such engines. Open rotors are one of several new technologies 

offering potential solutions for the next generation aircraft, predicted to provide a 25–30% 

reduction in specific fuel consumption & CO2 emissions relative to current, equivalent 

turbofan engines, as well as possible NOx advantages. There are substantial challenges 

associated with open rotors including noise, aircraft integration, certification requirements, 

accessibility & maintenance, etc – however it is believed that all can be overcome. 

10.4 Current Annex 16, Vol. II certification requirements are not applicable to such technologies 

because of the markedly different physical configuration. For example, small core sizes 

pose particular problems of sampling and measurement; ability to feather blades would 

mean difficulty in defining idle thrust setting. 

10.5 Therefore Working Group 3 were asked to include a recommendation in their report to the 

CAEP Steering Group that certification procedures be developed for alternative engine 

architectures, such as open rotors, that may not be able to certify using current procedures 

in Annex 16 Vol. II.

10.5 Discussion clarified that likely certification date would be late 2010; cruise NOx is not linked 

to LTO NOx; rules already exist for noise measurements.

10.6 WG3 accepted the recommendation for inclusion of this as a CAEP/9 work item

Action 6.22: Propose development of certification procedures for alternative engine 

architectures, such as open rotors, that may not be able to certify using current procedures 

in Annex 16 Vol. II as a CAEP/9 work item [Rapporteurs]

c. WG3 ad-hoc group telecon schedule_090406_v2

This was an updated telecon schedule until end September 2009

11 Preparations for WG3 report to SG2009

The Rapporteurs proposed structuring the report to SG similarly to that presented to earlier 

SG meetings ie they would draft the report, looking to the Task Group Leads to provide the 

sections related to their TG responsibilities. WG3 concurred with this proposal.

12 Next Meeting

At the request of the CAEP Secretariat the next meeting is now rescheduled for the week 

Sept 28 - Oct 2, still in Montreal

The Rapporteurs closed the meeting with thanks to UK BERR and Peter Newton as LTTG 

Lead for hosting not only the WG3 meeting but also the FBRT Workshop and the IE NOx 

Goals Update meeting during the two weeks.
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Attachment A:

ICAO CAEP/8 WG3 Emissions Technical Working Group 

Sixth Meeting: April 1 - 3, 2009, London, UK 

ATTENDANCE

Name Organisation / Affiliation

Lister, Dave

Holsclaw, Curtis

Civil Aviation Authority (CAA), UK

Federal Aviation Administration (FAA), USA

Allyn, Dan

Andreini, Antonio

Arrowsmith, Steve

Dantec, Delphine

Dikstra, Wieger

Dudebout, Rudy

Dodds, Will

Eyers, Chris

Gupta, Mohan

Hawkins, Betty

Herms, Erika

Hess, Cesar

Hoermann, Werner

Husse, Olivier

Iovinelli, Ralph

Madden, Paul

Manzoni, Helene

McDonald, Ted

McQueen, Ed

Miake-Lye, Rick

Newton, Peter

Plaisance, Christophe

Plohr, Martin

Rindlisbacher, Theo

Rollin, Gilles

Roetger, Thomas

Rutherford, Dan

Ryman Jenny

Saito, Marcelo

Sepulveda, Dom

Spears, Matthew

Tanaka, Tetsuya

Wayson, Roger

Wetzel, Frank

Worth, Roger

Boeing / ICCAIA

University of Florence, Italy

European Aviation Safety Agency (EASA), EU

Air France / IATA

Ministry of Environment, Netherlands

Honeywell / ICCAIA

General Electric (GE) / ICCAIA

QinetiQ, UK

FAA, USA

Air Transport Association / IATA

EASA, EU

ANAC / Brazil

EASA, EU

Airbus / ICCAIA

FAA, USA

Rolls-Royce / ICCAIA

DGAC / France

Transport Canada / Canada

FAA, USA

Aerodyne, USA

BERR, UK

Airbus / ICCAIA

DLR / Germany

FOCA / Switzerland

Snecma / ICCAIA

IATA

ICCT / ICSA

Swedish Transport Authority

ANAC, Brazil

P&W, / ICCAIA

EPA, USA

ICAO Secretariat

Volpe, USA

UBA, Germany

DfT, UK
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Attachment B:

ICAO CAEP/8 WG3 Emissions Technical Working Group 

Sixth Meeting: April 1-3, 2009, London, United Kingdom

LIST OF PAPERS

WP 

No.

Title Agenda 

Item

Prepared by

WP6-01 Final Meeting Schedule 2b Rapporteurs

WP6-02 Final Agenda 2c Rapporteurs

WP6-03 Draft Report of 5th WG3 meeting – Tokyo, Japan 3 Rapporteurs

WP6-03 

(rev)

Final Report of 5th WG3 meeting – Tokyo, Japan 3 Rapporteurs

WP6-04 Progress Report from LTTG 5 LTTG Lead

WP6-05 Initial Report on the Fuel Burn Technology Workshop 5a IEs

WP6-06 Initial Report on NOx Emissions Technology Goal Review/Update 5b IEs

WP6-07 Progress Report from CETG 6 CETG Lead

WP6-08 Progress Report from CTG 7 CTG Lead

WP6-09 Updates on Environmental Activities in ICAO and other UN bodies 4, 10a Secretariat

WP6-10 Characterizing the CO2 Intensity of Commercial Aircraft under a 

Potential Airframe Standard

4c ICSA

WP6-11 Consideration of CO2 Standards for Aircraft Engines 4c ICCAIA

WP6-12 Potential Issues Associated with the Certification of Open Rotor 

Engines for Emissions

10b ICCAIA

WP6-13 Fuel Efficiency Metric ad-hoc Group – Progress Report and 

Additional Tasks

4a, 9f FEMah Lead

WP6-14 Production Cut-Off 7 U.S. EPA

WP6-15 Additions to the ICAO Databank 7 U.S. EPA

WP6-16 Revision of Exemption Provisions 7 U.S. EPA

WP6-17 NOx Scenarios for MODTF Goals/Trends Analysis 3b ICCAIA

WP6-18 CAEP8_WG3_CETG6_WP05 (Emissions vs Thrust Final) 9c CETG Lead

WP6-19 CAEP8_WG3_CETG6_WP07 (Forward-Ambient for Advanced 

Calcs)

9c CETG Lead

WP6-20 CAEP8_WG3_CTG6_WP03 (CIS Aircraft PM V1_0) 9d CTG Lead

IP No. Title Agenda 

item

Prepared by

IP6-01 WG3 Membership - updated April 2009 2a Rapporteurs

IP6-02 Final List of WG3 Plenary Papers 2d Rapporteurs

IP6-03 

and App

Further Information About ICCAIA Fuel Consumption Scenarios 5c ICCAIA

IP6-04 CAEP Impacts Workshop Recommendations Matrix 8 Rapporteurs

IP6-05 What is an Open Rotor? 10b Rolls-Royce, GE 

Snecma

IP6-06 SBAC Aviation and Environment Briefing Papers; Open Rotor 

Engines

10b SBAC
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IP6-07 Collection of past CAEP material; CO2 Standard and Aircraft 

Efficiency Parameters

4c ICCAIA

IP6-08 Commercial Aircraft System Fuel Efficiency Metric for Use in CAEP 

Environmental Goals Trends Assessment

9f FEMah Lead

FL No. Title Agenda 

item

Prepared by

FL6-01 NOx Assumptions for the “Government” Environmental Goals 

Scenario

3b QinetiQ

FL6-02 ICCAIA Response to EPA Papers on Production Cut Off (WP6-14)

and Engine Exemptions (WP6-16)

7 ICCAIA

FL6-03 CAEP/WG3 initial response to task requests from GIACC/3 to CAEP 4 Rapporteurs

FL6-04 WG3 ad-hoc group telecon schedule_090406_v2 10c TG leads
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Attachment C:

ICAO CAEP/8 WG3 Emissions Technical Working Group 

Sixth Meeting: 1 - 3 April 2009, London UK

AGREED ACTIONS

Action 

Item No.

Item Agenda

Item

Action by: Timetable

[Status as of August 2009]

6.1 Convene group to review NOx improvement factors to be applied in ‘government’ 

scenarios and to report back to WG3 by Friday

3b CJE 3 April [Done]

6.2 Pass the recommendation (ii) on NOx improvement factors on to MODTF 3b CJE Asap [Done]

6.3 To consider the ICSA proposals in scoping the work required to develop a CO2 

standard

3c CTG 3 April [Done

6.4 Develop the initial response on GIACC/3 requests and report back to WG3 by

Friday for approval

3 Rapporteurs 3 April [Done]

6.5 Forward initial response of WG3 to GIACC/3 requests to CAEP Secretariat by end 

of April

3 Rapporteurs End April [Done]

6.6 Request FBRT IEs to provide written paper to WG3 on Workshop 5a LTTG Lead 17 April [Done]

6.7 ICCAIA to interact with IE group to address data concerns and expectations 5a ICCAIA Asap [on-going]

6.8 Request NOx IEs to provide written paper to WG3 on Goals review / update 5b LTTG Lead 17 April [Done]

6.9 Provide WG2 TG4 with the guidance material on emissions versus thrust 

relationship, including the language caveats, as provided in Appendix A to CETG6 

WP05 [WG3-WP6-18] for inclusion in the ICAO Airport Air Quality Guidance 

Manual.

6 Rapporteurs Before next WG2 meeting 

[Done]

6.10 Provide WG2 TG4 with “Guidelines For Including Effects Of Ambient Conditions 

And Forward Air Speed In Emissions Calculations Using Advanced Modelling 

Methods” as provided in CETG6 WP07 [WG3-WP6-19] for inclusion in the ICAO 

Airport Air Quality Guidance Manual.

6 Rapporteurs Before next WG2 meeting 

[Done]

6.11 WG3 report to SG2009 to reflect approval of ICCAIA request to defer delivery of 

remit item E.09.1 report until CAEP/8

6 Rapporteurs In WG3 report to SG2009 

[Done]

6.12 Consider proposals of WP6-14 and report back to WG3 7 CTG 3 April [Done]

6.13 Consider proposals of WP6-16 & comments in FL6-02 and report back to WG3 7 CTG 3 April [Done]

6.14 Provide MODTF with the information on the Estimation of PM Emissions from CISManufactured Engines contained in CTG6-WP03 [WG3-WP6-20].7 Rapporteurs Before next MODTF 

meeting [Done]

6.15 WG3 report to SG2009 to include offer of carrying out a scoping study for CAEP/8 7 Rapporteurs In WG3 report to SG2009 
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Action 

Item No.

Item Agenda

Item

Action by: Timetable

[Status as of August 2009]

on the likely work required to develop a potential aircraft CO2 emissions certification 

requirement.

[Done]

6.16 Provide comments on latest updates of ETM as provided in CTG WP6/06 by May 

22.

7 All WG3 

members

22 May 

6.17 Develop an initial response to request related to follow-on from CAEP Impacts 

Workshop and report back during this meeting

8 Ad Hoc group 3 April [Done]

6.18 Pass recommendation on formation of an ITF to co-ordinators of the Workshop for 

inclusion in their submission to SG2009. [Rapporteurs]

8 Rapporteurs End April [Done]

6.19 Request a progress report of the WG1 IE Noise Technology Review to assist WG3 

FBRT IEs [LTTG Lead]

9b LTTG Lead End April [Done]

6.20 Request an early copy of the WG2 ATM IE report to assist WG3 FBRT IEs [LTTG 

Lead]

9c LTTG Lead End April [Done]

6.21 Prepare paper on Fuel Efficiency Metric issues for SG2009 9f FEMah group For SG2009 [Done]

6.22 Propose development of certification procedures for alternative engine 

architectures, such as open rotors, that may not be able to certify using current 

procedures in Annex 16 Vol. II as a CAEP/9 work item.

10b Rapporteurs For SG2009 [Done]
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Attachment D:

ICAO CAEP/8 WG3 Emissions Technical Working Group 

Sixth Meeting: April 1-3, 2009, London, United Kingdom

WG3 INITIAL RESPONSE TO TASK REQUESTS FROM GIACC/3 TO CAEP

Request 2. CAEP is asked to address the development of a new efficiency metric that takes 

into account alternative fuels.

WG3 initial response: For kerosene-like “drop-in” fuels, the development of any fuel efficiency 

metric to include emissions from the life cycle of alternative fuels should be approached essentially 

as a two-part problem. These parts are an efficiency metric (based on fuel properties / aircraft 

technology / operational parameters), and a separate analysis taking account of life cycle 

emissions. CAEP has completed some preliminary work on a Commercial Aircraft System Fuel 

Efficiency Metric (CASFE). Use of non-kerosene-like fuels would seriously impact aircraft design

and affect fleet mixes; the current CAEP work has not addressed this matter. 

Potential CAEP/9 Work Item

Request 3. CAEP is asked to consider fuel conversion factors between existing fuels and 

potential biofuels.

WG3 initial response: Assuming this is purely an issue of the differences in the total life cycle 

emissions of different fuels, then this is substantially independent of the final user, ie it is not an 

aviation specific issue. A consistent methodology needs to be used for all energy uses and is best 

addressed from the energy supply side. Aviation needs reliable values for fuels that it might use, 

but does not need to be the developer of the information. We believe that these issues are being 

addressed by sources outside of CAEP such as CAAFI, SWAFEA. 

This is not a CAEP work item

Alternatively, if this question deals with CO2 emissions factors then this simply requires knowledge 

of the fuel composition that would need to be provided by the fuel supplier.

Request 4. Secretariat is asked to raise with CAEP the question of setting a CO2 

Standard.

WG3 initial response: CAEP has already devoted significant resources in attempting to develop 

aircraft efficiency parameters and continues work in related areas. Recognizing the importance of 

this matter some major considerations to address the question of setting a CO2 standard are the 

following:

 The development of appropriate metric(s) is a key issue that must be addressed as a first step.

 Any standard should apply to aircraft, not just engines alone.

 It may be easier to develop and implement an accurate methodology if it is based upon and 

solely applicable to new aircraft

 It is essential to avoid metrics and methodology that may contribute to perverse incentives and 

counterproductive influences on aircraft/engine development. Also there is a need to take into 

account operational considerations in order to avoid unintended consequences

 The implications for implementation by certification authorities and manufacturers
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 Defining the scope of work could be performed by WG3 to inform CAEP/8 discussion on this 

issue

 The level of work required in setting any potential standard should not be underestimated [note 

earlier CAEP work of a similar nature on cruise NOx methodology and fuel efficiency 

parameter]

Potential CAEP/9 + Work Item

- END -