Tel.: +1 (514) 954-8219 ext. 6726

Ref.: AN 1/61.2
AN 1/62.2 

# } 07/34 25 May 2007

Subject: Proposals for the amendment of Annex 16, Volumes I and II concerning Standards and Recommended Practices relating to environmental protection

Action required: Comments to reach Montreal by 7 September 2007

Sir/Madam,

1. I have the honour to inform you that the Air Navigation Commission, at the eleventh and twelfth meetings of its 174th Session held on 6 an d 8 March 2007, respectively, considered proposals developed by the seventh meeting of the Committee on Aviation Environmental Protection (CAEP/7) to amend the Standards and Recommended Practices (SARPs) in Annex 16 — Environmental Protection

, Volume I — Aircraft Noise and Volume II — Aircraft Engine Emissions relating to environmental protection.

2. The proposed amendments to Annex 16, Volumes I and II are shown in Attachments A and B, respectively. No recommendations concerning the stringency of the noise or emissions Standards
were made.

3. The purpose of the amendment of the SA RPs in Annex 16, Volume I is to clarify technical issues arising in the application of demonstr ation schemes and related gui dance for aircraft noise certification. The amendment to Annex 16, Volume II addresses technical issues, mainly concerning the
modernization of the demonstration schem es and guidance for engine certification.

4. May I request that any comments you wi sh to make on the amendment proposals be dispatched to reach me not later than 7 Septembe r 2007. The Air Navigation Commission has asked me to specifically indicate that comments r eceived after the due date may not be considered by the Commission and the Council. In this connection, should you antic ipate a delay in the receipt of your reply, please let
me know in advance of the due date.- 2 -

5. For your information, the proposed am endments to Annex 16, Volumes I and II are envisaged for applicability on 20 November 2008. Any comments you may have thereon would be appreciated.

6. The subsequent work of the Air Na vigation Commission and the Council would be greatly facilitated by specific statements on the acceptability or otherwise of the proposals. Please note that for the review of your comments by the Ai r Navigation Commission and the Council, replies are normally classified as “agreement with or without co mments”, “disagreement with or without comments” or “no indication of position”. If in your reply the expressions “no objections” or “no comments” are used, they will be taken to mean “agreement without comment” and “no indication of position”, respectively. In order to facilitate proper classificat ion of your response, a form has been included in Attachment E which may be completed and returned together with your comments, if any, on the proposals in Attachments A and B.

Accept, Sir/Madam, the assurances of my highest consideration.

Taïeb Chérif Secretary General

Enclosures:

A — Proposed amendment to Annex 16, Volume I

B — Proposed amendment to Annex 16, Volume II
C — Response formATTACHMENT A to State letter AN 1/61.2, AN 1/62.2 - 07/34

PROPOSED AMENDMENT TO

INTERNATIONAL STANDARDS AND RECOMMENDED PRACTICES

ENVIRONMENTAL PROTECTION

ANNEX 16
TO THE CONVENTION ON INTERNATIONAL CIVIL AVIATION

VOLUME I
AIRCRAFT NOISE

1. The text of the amendment is arranged to show delete d text with a line through it and new text highlighted with grey shading, as shown below:

1. Text to be deleted is shown with a line through it. text to be deleted

2. New text to be inserted is highlighted with grey shading. new text to be inserted

3. Text to be deleted is shown with a line through it followed by the replacement text which is highlighted with grey shading. new text to replace existing textTEXT OF PROPOSED AMENDMENT TO THE

INTERNATIONAL STANDARDS
AND RECOMMENDED PRACTICES

ENVIRONMENTAL PROTECTION

ANNEX 16
TO THE CONVENTION ON INTERNATIONAL CIVIL AVIATION

VOLUME I
AIRCRAFT NOISE

. . .

PART I. DEFINITIONS

. . .

Derived version of a helicopter . A helicopter which, from the point of view of airworthiness, is similar to the noise certificated prototype but incorporates chan ges in type design which may affect its noise characteristics adversely.

Note 1.— In applying the Standards of this Annex, a helicopter that is based on an existing prototype but which is considered by the certificating authority to be a new type design for airworthiness purposes
shall nevertheless be considered as a derived version if the noise source characteristics are judged by the certificating authority to be the same as the prototype.

Note 2.— “Adversely” refers to an increase of more than 0.3 EPN dB in any one of the noise certification levels for helicopters certificated according to Chapter 8 and 0.3 dB(A) in the certification level for helicopters certificated according to Chapter 11

.

. . .

PART II. AIRCRAFT NOISE CERTIFICATION

CHAPTER 1. ADMINISTRATION

. . .

1.10 Unless otherwise specified in this volume of the Annex, the date to be used by Contracting States in determining the applicability of the Standard s in this Annex shall be the date of application submitted to the State of Design for a type certificate, or the date of application under an equivalent prescribed procedure by the certificating authority of the State of Design . The application shall be effective for a duration equal to the period applied in the designation of the airworthiness regulations appropriate to the aircraft type, except in speci al cases where the certificat ing authority accepts an extension of this period.

. . .A-2

CHAPTER 2. SUBSONIC JET AEROPLANES — APPLICATION FOR TYPE
CERTIFICATE OF AIRWORTHINESS FOR THE PROTOTYPE ACCEPTED SUBMITTED
BEFORE 6 OCTOBER 1977

2.1 Applicability

Note.— See also Chapter 1, 1.9 1.10 and 1.11

.

2.1.1 The Standards of this chapter shall be a pplicable to all subsonic jet aeroplanes for which either the application for a certificate of airworthiness for the prototype Type Certificate was accepted
submitted , or another equivalent prescribed procedure w as carried out by the certificating authority, before 6 October 1977, except those aeroplanes:

. . .

c) powered by engines with a bypass ratio of less than 2 and for which either the application for a certificate of airworthiness for the prototype Type Certificate was accepted submitted , or another equivalent prescribed procedure was carried out by the certificating authority, before 1 January 1969, and for which a certificate of airworthiness for the individual aeroplane was first issued before 1 January 1976.

. . .

CHAPTER 3. 1.— SUBSONIC JET AEROPLANES — Application for Type Certificate of Airworthiness for the Prototype accepted submitted on or after 6 October 1977 and before 1 January 2006 2.— PROPELLER-DRIVEN AEROPLANES OVER 5 700 kg — Application for Type Certificate of Airworthiness for the Prototype accepted submitted on or after 1 January 1985 and before 17 November 1988 3.— PROPELLER-DRIVEN AEROPLANES OVER 8 618 kg — Application for Type Certificate of Airworthiness for the Prototype accepted submitted on or after 17 November 1988 and before 1 January 2006

3.1 Applicability

Note 1.— See also Chapter 1, 1.9 1.10 and 1.11

.

Note 2.— See Attachment E for guidance on interpretation of these applicability provisions.

3.1.1 The Standards of this chapter shall be applicable to:

a) all subsonic jet aeroplanes, including their derive d versions, other than aeroplanes which require a

runway 1 length of 610 m or less at maximum certificat ed mass for airworthiness, in respect of which either the application for a certificate of airworthiness for the prototype Type Certificate was accepted submitted , or another equivalent prescribed procedure was carried out by the certificating authority, on or after 6 October 1977 and before 1 January 2006;A-3

b) all propeller-driven aeroplanes, including thei r derived versions, of over 5 700 kg maximum certificated take-off mass (except those describe d in Chapter 6, 6.1), for which either the application for a certificate of airworthiness for the prototype Type Certificate was accepted
submitted , or another equivalent prescribed procedure was carried out by the certificating authority, on or after 1 January 1985 and before 17 November 1988, except where the Standards of Chapter 10 apply; and

c) all propeller-driven aeroplanes, including thei r derived versions, of over 8 618 kg maximum certificated take- off mass, for which either the application for a certificate of airworthiness for the prototype Type Certificate was accepted submitted , or another equivalent prescribed procedure was carried out by the certificating au thority, on or after 17 November 1988 and before 1 January 2006.

. . .

3.6 Noise certification reference procedures

. . .

3.6.2 Take-off reference procedure

. . .

d) the speed shall be the all-engines operating take -off climb speed selected by the applicant for use in normal operation, which shall be at least V 2 + 19 km/h (V 2 + 10 kt) but not greater than

V 2 + 37 km/h (V 2 + 20 kt) and which shall be attained as soon as practicable after lift-off and be maintained throughout the take-off noise certification test . The increment applied to V 2 shall be the same for all reference masses of an aeroplane model unless a difference in increment is substantiated based on performance characteristics of the aeroplane ;

. . .

CHAPTER 4. 1.— SUBSONIC JET AEROPLANES — Application for Type Certificate of Airworthiness for the Prototype accepted submitted on or after 1 January
2006 2.— PROPELLER-DRIVEN AEROPLANES OVER 8 618 kg — Application for Type Certificate of Airworthiness for the Prototype accepted submitted on or after 1 January 2006

4.1 Applicability

Note. — See also Chapter 1, 1.9 1.10 and 1.11

.

4.1.1 The Standards of this chapter shall be applicable to:

a) all subsonic jet aeroplanes, including their derive d versions, other than aeroplanes which require a

runway 1 length of 610 m or less at maximum certificat ed mass for airworthiness, in respect of which either the application for a certificate of airworthiness for the prototype Type Certificate was accepted submitted , or another equivalent prescribed procedure was carried out by the certificating authority, on or after 1 January 2006;A-4

b) all propeller-driven aeroplanes, including thei r derived versions, of over 8 618 kg maximum certificated take-off mass, for which either the application for a certificate of airworthiness fo r the
prototype Type Certificate was accepted submitted , or another equivalent prescribed procedure was carried out by the certificating authority, on or after 1 January 2006; and

. . .

CHAPTER 5. PROPELLER-DRIVEN AEROPLANES OVER 5 700 kg —

APPLICATION FOR TYPE CERTIFICATE OF AIRWORTHINESS FOR THE PROTOTYPE
ACCEPTED SUBMITTED BEFORE 1 JANUARY 1985

5.1 Applicability

Note 1.— See also Chapter 1, 1.9 1.10 and 1.11

.

. . .

5.1.2 The Standards of this chapter shall be applicable to all propeller-driven aeroplanes, including their derived versions, of over 5 700 kg maximum certificated take-off mass for which either the application for a certificate of airworthiness for the prototype Type Certificate was accepted submitted , or another equivalent prescribed procedure was carried out by the certificating authority, on or after 6 October 1977 and before 1 January 1985.

5.1.3 The Standards of Chapter 2, with the excep tion of Sections 2.1 and 2.4.2, shall be applicable
to derived versions and individual aeroplanes of over 5 700 kg maximu m certificated take-off mass and to which Standards of Chapter 6 do not apply and are of th e type for which the application for a certificate of airworthiness for the prototype Type Certificate was accepted submitted , or another equivalent prescribed procedure was carried out by the certificating authorit y, before 6 October 1977, and for which a certificate of airworthiness for the individual aeroplane was issued on or after 26 November 1981.

5.1.4 The Standards of Chapter 3, with the ex ception of Section 3.1, shall be applicable to all propeller-driven aeroplanes, including their derived ve rsions, of over 5 700 kg maximum take-off mass, for which either the application for a certificate of airworthiness for the prototype Type Certificate was accepted submitted , or another equivalent prescribed procedure was carried out by the certificating authority, on or after 1 January 1985.

. . .

CHAPTER 6. PROPELLER-DRIVEN AEROPLANES NOT EXCEEDING 8 618 kg — APPLICATION FOR TYPE CERTIFICATE OF AIRWORTHINESS
FOR THE PROTOTYPE ACCEPTED SUBMITTED BEFORE 17 NOVEMBER 1988

6.1 Applicability

Note 1.— See also Chapter 1, 1.9 1.10 and 1.11

.

Note 2.— See Attachment E for guidance on interpretation of these applicability provisions.

The Standards of this chapter shall be applicab le to all propeller-driven aeroplanes, except those aeroplanes specifically designed for aerobatic purposes or agricultural or fire fighting uses, of a maximum certificated take-off mass not exceeding 8 618 kg for which:A-5

a) the application for the certificate of airworthiness for the prototype Type Certificate was accepted
submitted , or another equivalent prescribed procedure was carried out by the certificating authority, on or after 1 January 1975 and befo re 17 November 1988, except for derived versions for which an application for a certificate of airworthiness Type Certificate was accepted
submitted , or another equivalent procedure was carried out by the certificating authority, on or after 17 November 1988, in which case the Standards of Chapter 10 apply; or

. . .

CHAPTER 8. HELICOPTERS

8.1 Applicability

Note.— See also Chapter 1, 1.9 1.10 and 1.11

.

. . .

8.1.2 For a helicopter for which the application for the certificate of airworthiness for the prototype Type Certificate was accepted submitted , or another equivalent prescribed procedure was carried out by the certificating authority, on or after 1 January 1985 , except for those helicopters specified in 8.1.4, the noise levels of 8.4.1 shall apply.

8.1.3 For a derived version of a helicopter for which the applicati on for a change of type design was accepted submitted , or another equivalent prescribed procedure was carried out by the certificating authority, on or after 17 November 1988, except for t hose helicopters specified in 8.1.4, the noise levels of 8.4.1 shall apply.

8.1.4 For all helicopters, including their derive d versions, for which the application for the certificate of airworthiness for the pro totype Type Certificate was accepted submitted , or another equivalent prescribed procedure was carried out by th e certificating authority, on or after 21 March 2002, the noise levels of 8.4.2 shall apply.

. . .

8.6 Noise certification reference procedures

8.6.1 General conditions

. . .

8.6.1.6 In 8.6.2 c), 8.6.3.1 c) and 8.6.4 c), the maximum normal operating rpm shall be taken as the highest rotor speed for each refere nce procedure corresponding to the airworthiness limit imposed by the manufacturer and approved by the certificating authority . Where a tolerance on the highest rotor speed is specified, the maximum normal operating rotor speed shall be taken as the highest rotor speed about which that tolerance is given. If the rotor speed is automatically linked with flight condition, the maximum normal operating rotor speed corresponding with that the reference flight condition shall be used during the noise certification procedure. If rotor speed can be changed by pilot action, the highest
maximum normal operating rotor speed specified in the flight manual limitation section for power

- on the
reference conditions shall be used during the noise certification procedure.

. . .A-6

CHAPTER 9. INSTALLED AUXILIARY POWER UNITS (APU)
AND ASSOCIATED AIRCRAFT SYSTEMS
DURING GROUND OPERATIONS

Note.— Standards and Recomme nded Practices for this chapter are not yet developed. In the meantime, guidelines provided in Attachment C may be used for noise certification of installed auxiliary power units (APU) and associated aircraft systems in:

a) all aircraft for which the application for a certificate of airworthiness for the prototype Type Certificate was accepted submitted , or another equivalent prescrib ed procedure was carried out by the certificating authority, on or after 6 October 1977; and

. . .

CHAPTER 10. PROPELLER-DRIVEN AEROPLANES NOT EXCEEDING 8 618 kg — APPLICATION FOR TYPE CERTIFICATE
OF AIRWORTHINESS FOR THE PROTOTYPE OR DERIVED VERSION
ACCEPTED SUBMITTED ON OR AFTER 17 NOVEMBER 1988

10.1 Applicability

Note 1.— See also Chapter 1, 1.9 1.10 and 1.11

.

. . .

10.1.2 For an aeroplane for which the applicat ion for the certificate of airworthiness for the
prototype Type Certificate or for all derived versions was accepted submitted , or another equivalent prescribed procedure was carried out by the certifica ting authority, on or after 17 November 1988, except for those aeroplanes specified in 10.1.4, the noise limits of 10.4 a) shall apply.

10.1.3 For aeroplanes specified in 10.1.2 which fail to comply with the Standards of this chapter and where the application for the certifi cate of airworthiness for the prototype Type Certificate or all derived versions was accepted submitted , or another equivalent prescribed procedure was carried out by the certificating authority, before 17 November 1993, the Standards of Chapter 6 shall apply.

10.1.4 For single-engined aeroplanes, except those aeroplanes specifically designed for aerobatic purposes and agricultural or fire fighting uses, sel f-sustaining powered sailplanes, float planes and amphibians, for which:

a) the application for the certificate of airworthiness for the prototype Type Certificate or their derived versions was accepted submitted , or another equivalent procedure was carried out by the certificating authority, on or after 4 November 1999, the noise limits of 10.4 b) shall apply;

b) an application for the certificate of airworthiness Type Certificate for the derived version was accepted submitted , or other procedure was carried out, on or after 4 November 1999, but for which the application for the certificate of airworthiness for the prototype Type Certificate , or another equivalent procedure was carried out by the certificating authority, before 4 November 1999, the noise limits of 10.4 b) shall apply;

. . .A-7

CHAPTER 11. HELICOPT ERS NOT EXCEEDING 3 175 kg
MAXIMUM CERTIFICATED TAKE-OFF MASS

11.1 Applicability

Note.— See also Chapter 1, 1.9 1.10 and 1.11

.

. . .

11.1.2 For a helicopter for which the applica tion for the certificate of airworthiness for th e prototype Type Certificate was issued submitted , or another equivalent prescribed procedure was carried out by the certificating authority, on or after 11 N ovember 1993, except for those helicopters specified in 11.1.4, the noise levels of 11.4.1 shall apply.

11.1.3 For a derived version of a helicopter for which the application for the certificate of
airworthiness Type Certificate for a change of type design was issued submitted , or another equivalent prescribed procedure was carried out by the certifica ting authority, on or after 11 November 1993, except for those helicopters specified in 11.1.4, the noise levels of 11.4.1 shall apply.

11.1.4 For all helicopters, including their de rived versions, for which the application for the
certificate of airworthiness for the prototype Type Certificate was accepted submitted , or another equivalent prescribed procedure was carried out by th e certificating authority, on or after 21 March 2002, the noise levels of 11.4.2 shall apply.

. . .

11.5 Noise certification reference procedure

11.5.1 General conditions

. . .

11.5.1.5 The maximum normal operating rpm shall be taken as the highest rotor speed corresponding to the airworthiness limit imposed by the manufacturer and approved by the certificating authority for overflight. Where a tolerance on the hi ghest rotor speed is specified, the maximum normal operating rotor speed shall be taken as the highest rotor speed about which that tolerance is given. If rotor speed is automatically linked with flight co ndition, the maximum normal operating rotor speed corresponding with that the reference flight condition shall be used during the noise certification procedure. If rotor speed can be ch anged by pilot action, the highest maximum normal operating rotor speed specified in the flight manual limitation section for power

- on the reference conditions shall be used during the noise certification procedure.

. . .

CHAPTER 12. SUPERSONIC AEROPLANES

12.1 Supersonic aeroplanes — application for

certificate of airworthiness for the prototype accepted Type Certificate submitted before 1 January 1975

12.1.1 The Standards of Chapter 2 of this Part, with the exception of maximum noise levels specified in 2.4, shall be applicable to all supe rsonic aeroplanes, including their derived versions, inA-8

respect of which either the application for th e certificate of airworthiness for the prototype Type
Certificate was accepted submitted , or another equivalent prescribed procedure was carried out by the certificating authority, before 1 January 1975, and for which a certificate of airworthiness for the individual aeroplane was first issued after 26 November 1981.

. . . 12.2 Supersonic aeroplanes — application for certificate of airworthiness for the prototype accepted Type Certificate submitted on or after 1 January 1975

Note.— Standards and Recommende d Practices for these aeroplanes are not yet developed but the noise levels of Chapter 3 of this Part applicable to s ubsonic jet aeroplanes may be used as guidelines for aeroplanes for which the application for a certificate of airworthiness for the prototype Type Certificate was accepted submitted , or another equivalent prescribed proce dure was carried out by the certificating authority, on or after 1 January 1975.

. . .

CHAPTER 13. TILT-ROTOR AIRCRAFT

Note 1.— Standards and Recommended Practices fo r this chapter are not yet developed. In the meantime, guidelines provided in Attachment F ma y be used for noise certification of tilt-rotor aircraft for which a type certificate of airwort hiness was issued the application for a Type Certificate was submitted or another equivalent prescribed procedur e was carried out by the certificating authority on or after 13 May 1998 and to provide data for land-use planning purposes.

. . .

APPENDIX 1. EVALUATION METHOD FOR NOISE CERTIFICATION OF
SUBSONIC JET AEROPLANES — APPLICATION FOR TYPE CERTIFICATE OF
AIRWORTHINESS FOR THE PROTOTYPE ACCEPTED SUBMITTED BEFORE
6 OCTOBER 1977

. . .

APPENDIX 2. EVALUATION METHOD FOR NOISE CERTIFICATION OF:

1.— SUBSONIC JET AEROPLANES — Application for Type Certificate of Airworthiness for the Prototype accepted submitted on or after
6 October 1977

2.— PROPELLER-DRIVEN AEROPLANES OVER 5 700 kg — Application for Type Certificate of Airworthiness for the Prototype accep ted submitted on or after 1 January 1985 and before 17 November 1988

3.— PROPELLER-DRIVEN AEROPLANES OVER 8 618 kg — Application for Type Certificate of Airworthiness for the Prototype accepted submitted on or after
17 November 1988

4.— HELICOPTERS

Note.— See Part II, Chapters 3, 4 and 8.A-9

. . .

2. NOISE CERTIFICATION TEST AND
MEASUREMENT CONDITIONS

Replace Section 2.2 as follows:

. . .

2.2 Test environment

2.2.1 Microphone locations

Locations for measuring noise from an aircraft in fli ght shall be surrounded by relatively flat terrain having no excessive sound absorption characteristics such as might be caused by thick, matted, or tall grass, shrubs, or wooded areas. No obstructions wh ich significantly influence the sound field from the aircraft shall exist within a conical space above th e point on the ground vertically below the microphone, the cone being defined by an axis normal to th e ground and by a half-angle 80° from this axis.

Note.— Those people carrying out the measurements could themselves constitute such obstructions.

2.2.2 Atmospheric conditions

2.2.2.1 Specifications

For the purposes of noise certification in this section the following specifications apply:

Time constant (of a first order system) is the time required for a device to detect and indicate 100*(1-1/e) percent (about 63%) of a step function change. (The mathematical constant, e , is the base number of the natural logarithm, approximately 2.7183 - also known as Euler’s number, or Napier’s constant .)

Distance constant (or response length) is the passage of wind (in meters) required for the output of a wind speed sensor to indicate 100*(1-1/e) percent (a bout 63%) of a step-function increase of the input speed.

Wind speed sample (at a certain moment) is the value measured at that moment for wind speed using a sensor/system with characteristics as follows:

Range: 1 m/s ( 3.6 km/h ) to more than 10 m/s ( 36 km/h ); Linearity: +/- 0.5 m/s ( 1.8 km/h ) over the specified range; and Distance constant (response length): less than 5 meters for systems having dynamic behaviour best characterised by a distance constant; or Time constant: less than 3 seconds for wind speeds at or above 5 m/s (1 8 km/h ) for systems having dynamic behaviour best characterised by a
time constant.A-10

Wind direction sample (at a certain moment) is the value obtained at that moment from a wind direction sensor/system with characteristics as follows:

Wind speed operating range: 1 m/s ( 3.6 km/h ) to more than 10 m/s ( 36 km/h ); Linearity: +/- 5 degrees over the specified range; and Resolution: 5 degrees.

Note.— For the entire wind sensing system used to obtain wind speed and direction samples, the combined dynamic characteristics, including physi cal inertia of the sensor(s), and any temporal processing, such as filtering of the sensor signal(s), or smoothing or averaging of the wind sensor data, shall be equivalent to a first order system (such as an R/C circuit) with a time constant of no greater than 3 seconds at a wind speed of 5 m/s ( 18 km/h ).

Wind vector (at a certain moment) . At least once every second the wind vector shall be determined. Its magnitude will be represented at a certain moment by the wind speed sample at that moment and the direction of the vector shall be represented by the wind direction sample at that moment.

Average wind speed shall be determined from the series of individual wind speed samples obtained during the aircraft test run, using a linear aver aging process over 30 seconds, or an averaging process that has a time constant of no more than 30 seconds, the result of which is read out at a moment approximately 15 seconds after the time at which the aircraft passes either over or abeam the microphone. Alternatively, each wind vector sha ll be broken down into its “along track” (u) and “cross-track” (v) components. The u and v components of the series of individual wind samples obtained during the aircraft test run shall be separately averaged using a linear averaging process over 30 seconds, or an averaging process that has a time constant of no more than 30 seconds, the result of which is read out at a moment approximately 15 sec onds after the time at which the aircraft passes either over or abeam the microphone. The average wind speed and direction (with respect to the track) shall then be calculated from the averag ed u and v components according to Pythagorean Theorem and “arctan(u/v)”.

Average cross-wind component shall be determined from the series of individual values of the “cross track” (v) component of the wind samples obtained during the aircraft test run, using a linear averaging process over 30 seconds or an averaging pr ocess that has a time constant of no more than 30 seconds, the result of which is read out at a moment approximately 15 seconds after the time at which the aircraft passes either over or abeam the microphone.

Maximum wind speed . The maximum value within the series of individual wind speed samples recorded every second over a period that spans the 10 dB-down time interval.

Maximum cross-wind component . The maximum value within the series of individual values of the “cross track” (v) component of the wind samples r ecorded every second over a period that spans the
10 dB-down time interval.

2.2.2.2 Except as provided in 2.2.2.5, the tests sh all be carried out under the following atmospheric
conditions:

a) no precipitation;

b) ambient air temperature not above 35°C and not below -10°C, and relative humidity not above 95 per cent and not below 20 per cent over the whole noise path between a point 10 m (33 ft) above the ground and the aircraft;A-11

Note.— Care should be taken to ensure that the no ise measuring, aircraft flight path tracking and meteorological instrumentation are operated within the environmental limitations specified by the manufacturer.

c) relative humidity and ambient temperature over th e whole noise path between a point 10 m (33 ft) above the ground and the aircraft altitude at the time of PNLTM, such that the sound attenuation due to atmospheric absorption in the one-third octave band centred on 8 kHz will not be more than 12 dB/100 m;

Note.— Section 7 of this appendix specifies the method for calculation of atmospheric absorption coefficients based on temperatu re, humidity, and frequency.

d) if the atmospheric absorption coefficients va ry over the PNLTM sound propagation path by more than ±0.5 dB/100 m in the 3 150 Hz one-third octave band from the value of the absorption coefficient derived from the meteorological meas urement obtained at 10 m above the surface, ‘layered’ sections of the atmosphere must be used to compute equivalent weighted sound attenuations in each one-third octave band, sufficien t sections being used to the satisfaction of the certificating authority; where multiple layering is not required, equivalent sound attenuations in
each one-third octave band shall be determin ed by averaging the atmospheric absorption coefficients for each such band at 10 m (33 ft) a bove ground level and at the flight level of the test aircraft at the time of PNLTM, for each measurements;

e) at 10 m (33 ft) above ground, for aeroplanes, the average wind speed shall not exceed 22 km/h (12 kt) and the average cross-wind component shall not exceed 13 km/h (7 kt). For helicopters, the average wind speed shall not exceed 19 km/h (10 kt) and the average cross-wind component shall not exceed 9 km/h (5 kt). For aeropl anes, the maximum wind speed shall not exceed 28 km/h (15 kt) and the maximum cross-wind component shall not exceed 18 km/h (10 kt). All wind speed samples shall be taken with the sensor installed such that the horizontal distance between the anemometer and any obstruction is at least 10 times the height of the obstruction.
Installation error for the wind direction sens or shall be no greater than 5 degrees; and

f) no anomalous meteorological or wind conditions that would significantly affect the measured
noise levels when the noise is recorded at th e measuring points specified by the certificating authority.

2.2.2.3 Meteorological measurements of ambient te mperature and relative humidity shall be obtained within 30 minutes of each noise test measurement. Meteorological data shall be interpolated to actual
times of each noise measurement. Wind measurements sha ll be obtained continuously during each aircraft

test run.

2.2.2.4 When a multiple layering calculation is re quired by 2.2.2.2 d), the atmosphere between the aircraft and 10 m (33 ft) above the ground shall be divi ded into layers of equal depth. The depth of the layers shall be set to not more than the depth of the narrowest layer across which the variation in the atmospheric absorption coefficient of the 3 150 Hz one- third octave band is not greater than ±0.5 dB/100 m, with a minimum layer depth of 30 m (100 ft). This shall apply over the propagation path at PNLTM. The mean of the values of the atmospheric absorption coefficients at the top and bottom of each layer may
be used to characterize the abso rption properties of each layer.

2.2.2.5 For helicopters the requirements of 2.2.2.2 b) , c) and d) shall only be applied at a point 10 m (33 ft) above ground.A-12

2.2.2.6 The atmospheric conditions shall be measu red within 2 000 m (6 562 ft) from the microphone locations and shall be representative of the conditions existing over the geographical area in which noise
measurements are made.

. . .

3. MEASUREMENT OF AIRCRAFT
NOISE RECEIVED ON THE GROUND

3.1 Definitions

For the purposes of this section th e following defin itions apply:

. . .

Sound incidence angle . In degrees, an angle between the principal axis of the microphone, as defined in

IEC 61094

- 3 1 and IEC 61094

- 4 2 , as amended and a line from the sound source to the centre of the diaphragm of the microphone.

Note.— When the sound incidence angle is 0°, the s ound is said to be received at the microphone at “normal (perpendicular) incident incidence ”; when the sound incidence angle is 90°, the sound is said to be received at “grazing incidence”. The principal axis of a meas urement microphone is through the centre of the diaphragm and perpendicular to it.

. . .

3.7 Analysis systems

. . .

3.7.3 The one-third octave band analysis system shall at least conform to the class 2 1 electrical performance requirements of IEC 61260 4 61260 2 as amended, over the range of one-third octave nominal midband frequencies from 50 Hz to 10 kHz inclusive.

Note 1.— The certificating authority may allow th e substitution of an analysis system that complies
with class 2 as an alternative to class 1 el ectrical performance requirements of IEC 61260 2

.

Note 2 .—Tests of the one-third octave band analysis syst em should be made acco rding to the methods
described in IEC 612604 4 61260 2 or by an equivalent procedure appr oved by the certificating authority, for relative attenuation, anti-aliasing filters, real-time operation, level linearity, and filter integrated response (effective bandwidth).

. . .

3.8 Calibration systems

The acoustical sensitivity of the measurement syst em shall be determined using a sound calibrator generating a known sound pressure le vel at a known frequency. The sound calibrator shall at least conform to the class 1L requirements of IEC 60942 5 60942 3 as amended.

. . .A-13

1 IEC 61094

- 3: 1995 entitled “Measurement microphones

— Part 3: Primary method for free

- field calibration of laboratory standard microphones by the reciproc ity technique”. Th is IEC publication may be obtained from the Central Office of the
International Electrotechnical Commission, 3 rue de Vare mbé, Geneva, Switzerland.

2 IEC 61094

- 4: 1995 entitled “Measurement microphones

— Part 4: Specifications for wo rking standard microphones”. This IEC pub lication may be obtained from the Central Office of the International Electrotechnical Commission, 3 rue de Varembé, Geneva, Switzerland.

3 1 IEC 61265: 1995 entitled “Electro acoustics — Instruments for measurement of aircrft nois e — Performance requirements for systems to measure one-third-octave band sound pressure leve ls in noise certification of tr ansport-category aeroplanes”. This IEC publication may be obtained fro m the Central Office of the Internatio nal Electrotechnical Commission, 3 rue de Varembé, Geneva, Switzerland.

4 2 IEC 61260: 1995 entitled “Electro acoustics — Octave-band and fractional-octave band filters”. This IEC publication may be
obtained from the Central Office of the International Electrotechnical Commission, 3 rue de Varembé, Geneva, Switzerland.

5 3 IEC 60942: 1997 2003 entitled “Electroacoustics – S ound calibrators”. This IEC publica tion may be obtained from the
Central Office of the International Electrotechnical Commission, 3 rue de Varembé, Geneva, Switzerland.

. . .

5. REPORTING OF DATA TO THE
CERTIFICATING AUTHORITY

. . .

5.2 Data reporting

. . .

5.2.3 The following atmospheric environmental da ta, measured immediately before, after, or during each test at the observation points prescribed in Section 2 of this appe ndix shall be reported:

a) air temperature and relative humidity;

b) maximum, minimum and average wind velocities speeds and wind directions ; and

. . .

APPENDIX 3. NOISE EVALUATION METHOD FOR NOISE CERTIFICATION
OF PROPELLER-DRIVEN AEROPLANE S NOT EXCEEDING 8 618 kg —
APPLICATION FOR TYPE CERTIFICATE OF AIRWORTHINESS FOR
THE PROTOTYPE ACCEPTED SUBMITTED BEFORE 17 NOVEMBER 1988

. . .A-14

APPENDIX 4. EVALUATION METHOD FOR NOISE CERTIFICATION
OF HELICOPTERS NOT EXCE EDING 3 175 kg MAXIMUM
CERTIFICATED TAKE-OFF MASS

. . .

2. NOISE CERTIFICATION
TEST AND MEASUREMENT
CONDITIONS

. . .

2.2 Test environment

. . .

2.2.2 The tests shall be carried out under the following atmospheric conditions:

a) no precipitation;

b) relative humidity not higher than 95 per cent or lower than 20 per cent and ambient temperature
not above 35°C and not below 2° C at a height between 1.2 m (4 ft) and 10 m (33 ft) above ground (if the measurement site is within 2 000 m of aerodrome weather measuring equipment, the aerodrome reported temperature, relative humidity and wind speed may be used). Combinations
combinations of temperature and humidity which lead to an absorption coefficient in the 8 KHz one-third octave band of greater than 10 dB/100 m shall be avoided. Absorption coefficients as a function of temperatur e and relative humidity are given in Section 7 of Appendix 2 or SAE ARP

866 A ;

Note.— Absorption coefficients as a function of temperature and relative humidity are given in Section 7 of Appendix 2 or SAE ARP 866A

. c) at a height between 1.2 m (4 ft) and 10 m (33 ft) above ground, average wind speed shall not exceed 19 km/h (10 kt) and the average crosswind average wind speed component at right angles to the direction of flight shall not exceed 9 km/h (5 kt) at a height between 1.2 m (4 ft) and 10 m (33 ft) above ground ; and

Note.

— Average wind speed is defined over a 30

- second time period.

d) no other anomalous meteorological conditions that would significantly affect the noise level when recorded at the measuring points specifi ed by the certificating authority.

Note.— Meteorological specifications are gi ven in Section 2.2.2.1 of Appendix 2.

2.2.3 The atmospheric conditions shall be measure d within 2 000 m (6 562 ft) from the microphone locations and shall be representative of the conditions existing over the geographical area in which noise
measurements are made.

2.3 Flight path measurement

. . .

2.3.1 The helicopter position relative to the flight path reference point shall be determined by a method independent of normal flight instrumentation, such as radar tracking, theodolite triangulation orA-15

photographic scaling techniques, approved by the certificating authority.

2.3.2 The helicopter noise shall be measured ove r a distance sufficient to ensure adequate data during the period that the noise is within 10 dB(A) of the maximum value of dB(A).

2.3.3 2.3.2 Position and performance data required to make the adjustments referred to in Section 5 of this appendix shall be recorded at an approve d sampling rate. Measuring equipment shall be approved by the certificating authority.

2.4 Flight test conditions

2.4.1 The helicopter shall be flown in a stabili zed flight condition over a distance sufficient to ensure that the time-varying sound level is measure d during the entire time period that the sound level is within 10 dB(A) of L Amax

.

Note.— L Amax is defined as the maximum of the A-fre quency-weighted S-time-weighted sound level measured during the test run.

2.4.1 2.4.2 The helicopter flyover noise test shall be c onducted at the airspeed referred to in Part II, Chapter 11, 11.5.2 with such airspeed adjusted as necessary to produce the same advancing blade tip
Mach number as associated with the reference conditions.

2.4.2 2.4.3 Advancing The reference advancing blade tip Mach number (Mat) (M R ) is defined as the ratio of the arithmetic sum of blade tip rotational speed (Vt) (V T ) and the reference helicopter true airspeed (Vr) (V

r ) divided by the speed of sound (c) (c R ) at 25°C such that:

(Vt + Vr) Mat =

c

(V T + V

r ) M R = c R

3. NOISE UNIT DEFINITION

3.1 The value of sound exposure level L AE is defined as the level, in decibels, of the time integral of squared A-weighted sound pressure (P A ) over a given time period or event, with reference to the square of the standard reference sound pressure (P 0 ) or of 20 micropascals μ Pa and a reference duration of one
second.

3.2 This unit is defined by the expression:

where T 0 is the reference integration time of one second and ( t 2 – t 1) is the integration time interval.

3.3 The above integral can also be expressed be approximated from periodically sampled

measurement as: 

### dt P t P

T L A t

t AE 2

0 2

1 0 

### ) ( 1 log 10 ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛

= 

# ∫A-16

where L A ( t ) is the time varying A

- weighted A-frequency-weighted S-time-weighted sound level and n is the number of samples per second

.

3.4 The integration time ( t 2 – t 1) in practice shall not be less than the 10 dB-down time interval during which L A ( t ) first rises to within 10 dB(A) of below its maximum value (L Amax ) and last falls below 10 dB(A) of its maximum value.

3.5 The SEL may be approximated by the following expression:

L AE = L Amax + ∆ A

where ∆ A is the duration allowance given by

∆ A = 10 log 10 τ

where τ = ( t 2

– t 1)/2.

L Amax is defined as the maximum level, in decibels, of the A

- weighted sound pressure (slow response) with reference to the square of the standard reference sound pressure P 0

.

4. MEASUREMENT OF
HELICOPTER NOISE RECEIVED
ON THE GROUND

4.1 General

4.1.1 All measuring equipment shall be approved by the certificating authority.

4.1.2 Sound pressure level data for noise ev aluation purposes shall be obtained with acoustical equipment and measurement practices that conform to the specifications given in 4.2.

4.2 Measurement system

The acoustical measurement system shall consist of approved equipment equivale nt to the following:

a) a microphone system with frequency response comp atible with measurement and analysis system accuracy as stated in performance characteristics meeting the requirements of 4.3;

b) tripods or similar microphone mountings th at minimize interference with the sound being 

### dt T L t L t

t AE A 10 ) ( 2

1 0 

### 10 1 log 10 

# ∫

=



# ∑ −

= 

### = ) 1 2 (

1 )) ( 1

. 0 (

0 

### 10 1 log 10 t t n

t t L

AE A 

### T LA-17

measured;

c) recording and reproducing equipment character istics, frequency response, and dynamic range compatible with the response and accuracy requirements with performance characteristics meeting the requirements of 4.3; and

d) acoustic sound calibrators using sine wave or broadband noise signals of known sound pressure
level meeting the requirements of 4.3 . If broadband noise is used, the signal shall be described in terms of its average and maximum root

- mean

- square (rms) value for non

- overload signa l level.

4.3 Sensing, recording and reproducing equipment

4.3.1 The microphone shall be of the type that has a pressure or a diffuse-field sensitivity whose frequency response is nearly flat at grazing incidence.

4.3.1 4.3.2 With the approval o f the certificating authority the sound level produced by the helicopter may be stored on a magnetic tape reco rder for later evaluation. Alternatively, the A

- weighted sound level time history may be written onto a graphic level recorder set at “slow” respo nse from which the SEL value may be determined or the SEL may be di rectly determined from an integrating sound level meter complying with the Standards of Internationa l Electrotechnical Commission (IEC) Publication No.

804 1 for a Type 1 instrument set at “ slow” response. The SEL may be directly determined from an integrating sound level meter. Alte rnatively, with the approval of the certificating authority the sound pressure signal produced by the helicopter may be stored on an analog magnetic tape recorder or a digital
audio recorder for later evaluation usin g an integrating sound level meter. The SEL value may also be
calculated from one-third octave band data obtai ned from measurements made in conformity with Section 3 of Appendix 2 and using the equation given in 3.3 . In this case each one-third octave band sound pressure level shall be weighted in accord ance with the A-weighting values given in IEC
Publication No. 651

. 1 IEC Publication 61672-1. 1

4.3.2 4.3.3 The characteristics of the complete system shall comply with the recommendations given in IEC Publication No. 651 1 with regard to the sections concerning microphone, amplifier and indicating instrument characteristics. The text an d specifications of IEC Publication No. 651 entitled
“Sound Level Me ters” are incorporated by reference into this section and are made a part hereof. The characteristics of the complete system with regard to directional response, frequency weighting A, time weighting S (slow), level linearity, and response to short-duration signals, shall comply with the class 1 specifications given in IEC 61672-1. 1 The complete system may include tape recorders or digital audio recorders according to IEC 61672-1. 1

Note.— The certificating authority may approve the use of equipment compliant with class 2 of the current IEC standard, or the use of equipment compliant with class 1 or Type 1 specifications of an earlier standard, if the applicant can show that th e equipment had previously been approved for noise certification use by a certificating authority. This in cludes the use of a sound level meter and graphic level recorder to approximate SEL using the equation given in 3.3. The certificating authority may also approve the use of magnetic tape recorders that co mply with the specifications of the older IEC 561 standard if the applicant can show that such use had previously been approved for noise certification use by a certificating authority.

4.3.3 If a tape recording is used, the tape recorder shall comply with IEC Recommendation 561

. 1

4.3.4 The response of the complete system to a sensibly plane progressive sinusoidal wave ofA-18

constant amplitude shall lie within the tolerance li mits specified in Table IV and Table V for Type I instruments in IEC Publication No. 651, for weighting curve A over the frequency range 45 to 11 500 Hz.

4.3.5 4.3.4 The overall sensitivity of the measuring system shall be checked before tests start , after testing has ended, and at intervals during testing using an acoustic a sound calibrator generating a known sound pressure level at a known frequency. The sound calibrator should conform to the class 1 requirements of IEC 60942. The output of the acoustic sound calibrator shall have been checked by a standardizing laboratory within 6 months of the test series; tolerable changes in output shall be not more than 0.2 dB. The equipment shall be considered satis factory if the variation over the period immediately prior to and immediately following each test series with in a given test day is not greater than 0.5 dB.

Note.— A pistonphone operating at a nominal 124 dB and 250 Hz is generally used for this purpose. The certificating authority may approve the use of calibra tors compliant with class 2 of the current IEC standard, or the use of calibrators compliant with cl ass 1 of an earlier standard, if the applicant can show that the calibrator had previously been appr oved for noise certification use by a certificating authority.

4.3.5 When the sound pressure signals from the helicopter are recorded, the SEL may be determined by playback of the recorded signals in to the electrical input facility of an approved sound level meter that conforms to the class 1 perfo rmance requirements of IEC 61672-1. The acoustical sensitivity of the sound level meter shall be establishe d from playback of the associated recording of the signal from the sound calibrator and kn owledge of the sound pressure level produced in the coupler of the sound calibrator under the environmental conditions preva iling at the time of the recording of the sound from the helicopter.

4.3.6 A wind screen should be employed with the microphone during all measurements of helicopter noise sound levels . Its characteristics should be such that when it is used, the complete system including the wind screen will meet the specifications above. Its insertion loss at the frequencies of the pistonphone should also be known and included in th e acoustic reference level for analysis of the

measurements. in 4.3.3.

4.4 Noise measurement procedures

4.4.1 The microphone shall be of the pressure

- sensitive type designed for nearly uniform grazing incidence response.

4.4.2 4.4.1 The microphone shall be mounted with the centre of the sensing element 1.2 m (4 ft) above the local ground surface and shall be oriented fo r grazing incidence, i.e. with the sensing element substantially in the plane defined by the nominal fli ght path of the helicopter and the measuring station. The microphone mounting arrangement shall minimize th e interference of the supports with the sound to
be measured.

4.4.3 4.4.2 If the noise helicopter sound pressure signal is tape

- recorded, the frequency response of the electrical system shall be determined, during each test series, at a level within 10 dB of the full-scale reading used during the tests, utilizing random or pseudo-random pink noise. The output of the noise generator shall have been checked by an approved st andards laboratory within six months of the test series, and tolerable changes in the relative output at each one-third octave band shall be not more than
0.2 dB. Sufficient determinations sh all be made to ensure that the overall calibration of the system is
known for each test.

4.4.4 4.4.3 Where a an analog magnetic tape recorder forms part of the measuring chain, each reelA-19

of magnetic tape shall carry 30 s of this electrica l calibration signal at its beginning and end for this purpose. In addition, data obtaine d from tape-recorded signals shall be accepted as reliable only if the
level difference in the 10 kHz one-third octave band f iltered levels of the two signals is not more than
0.75 dB.

Note.— Digital audio recorders typically do not exhib it substantial variation in frequency response or level sensitivity, therefore the pink noise testing described in 4.4.3 is not necessary for digital audio
recorders.

4.4.5 4.4.4 Background The A-frequency-weighted sound level of the background noise, including ambient noise and electrical noise of the measurement syst ems, shall be determined in the test area with the system gain set at levels which will be used for helicopter noise measurements. If helicopter sound pressure levels do not exceed b ackground sound pressure levels If the L Amax of each test run does not exceed the A-frequency-weighted sound level of the background noise by at least 15 dB(A), flyovers at an approved lower height may be used and the resu lts adjusted to the reference measurement point height by an approved method.

1 Available from the Central Office of the International Electrotechnical Commis sion, 3 rue de Varembé, Geneva,
Switzerland

. IEC 61672-1: 2002 entitled “Electroacous tics – Sound level meters – Part I: Specifications”. This IEC publication may be obtained from the Bureau central de la Co mmission électrotechnique intern ationale, 1 rue de Varembé, Geneva, Switzerland.

2 IEC 60942: 2003 entitled “Electroacoustics – Sound calibrators”. This IEC publication may be obtained from the Bureau central de la Commission électrotechnique internationale, 1 rue de Varembé, Geneva, Switzerland.

. . .

APPENDIX 6. NOISE EVALUATION METHOD FOR NOISE CERTIFICATION
OF PROPELLER-DRIVEN AEROPLANE S NOT EXCEEDING 8 618 kg —
APPLICATION FOR TYPE CERTIFICATE OF AIRWORTHINESS FOR
THE PROTOTYPE ACCEPTED SUBMITTED ON OR AFTER 17 NOVEMBER 1988

. . .

2. NOISE CERTIFICATION TEST AND
MEASUREMENT CONDITIONS

. . .

2.2 General test conditions

. . .

2.2.2 The tests shall be carried out under the following atmospheric conditions:

. . .

c) average wind speed shall not exceed 19 km/h ( 10 kt) and crosswind average wind speed shall not exceed 9 km/h (5 kt);

Note.— Average wind speed is defined over a 30

- second time period. Meteorological specifications are defined in Section 2.2.2.1 of Appendix 2.

. . .A-20

2.2.3 The atmospheric conditions shall be measu red within 2 000 m (6 562 ft) from the microphone locations and shall be representative of the conditions existing over the geographical area in which noise
measurements are made.

. . .

Replace Section 4 as follows:

4. MEASUREMENT OF AEROPLANE
NOISE RECEIVED ON THE GROUND

4.1 General

4.1.1 All measuring equipment shall be approved by the certificating authority.

4.1.2 Sound pressure level data for noise evalua tion purposes shall be obtained with acoustical equipment and measurement practices that conform to the specifications given hereunder in 4.2.

4.2 Measurement system

The acoustical measurement system shall consist of approved equipment equivale nt to the following:

a) a microphone system designed to have mostly-u niform frequency response for sound incident on the diaphragm from random directions, or in th e pressure field of a closed cavity, with performance characteristics meeting the requirements of 4.3;

b) microphone installation and mounting hardware th at minimizes interference with the sound being measured, in the configuration specified in 4.4;

c) recording and reproducing equipment performan ce characteristics meeting the requirements of 4.3; and

d) sound calibrators using sine wave signals of known sound pressure level meeting the requirements of 4.3.

4.3 Sensing, recording and reproducing equipment

4.3.1 The sound level produced by the aeroplane sh all be recorded. A magnetic tape recorder, graphic level recorder or sound level meter is accep table at the option of the certificating authority.

4.3.2 The characteristics of the complete system with regard to directional response, frequency weighting A, time weighting S (slow), level linearity, and response to short-duration signals, shall comply with the class 1 specifications given in the IEC Publication 61672-1. 1 The complete system may include tape recorders according to IEC 61672-1. 1

Note.— The certificating authority may approve the use of equipment compliant with class 2 of the current IEC standard, or the use of equipment compliant with class 1 or Type 1 specifications of earlier standards, as an alternative to equipment compliant with class 1 of the current IEC standard, if theA-21

applicant can show that the equipment had previou sly been approved for noise certification use by a certificating authority. The certificating authority may also approve the use of magnetic tape recorders that comply with the specifications of the older IE C 561 standard if the applicant can show that such use had previously been approved for noise certific ation use by a certificating authority.

4.3.3 The over-all sensitivity of the measuring system shall be checked before tests start, after testing has ended, and at intervals during tes ting using a sound calibrato r generating a known sound pressure level at a known frequency. The sound calibrato r should conform to the class 1 requirements of

IEC 60942. 2

Note.— The certificating authority may approve the u se of calibrators compliant with the class 2 specifications of the current IEC standard, or the u se of calibrators compliant with class 1 of an earlier standard, if the applicant can show that the cali brator had previously been approved for noise certification use by a certificating authority.

4.3.4 When the sound from the aeroplane is tape recorded, the maximum A-frequency-weighted and S-time-weighted sound level may be determined by playback of the recorded signals into the electrical input facility of an approved sound leve l meter that conforms to the class 1 performance requirements of IEC 61672-1. 1 The acoustical sensitivity of the s ound level meter shall be established from playback of the associated recording of the si gnal from the sound calibrator and knowledge of the sound pressure level produced in the coupler of th e sound calibrator under the environmental conditions prevailing at the time of the recording of the sound from the aeroplane.

4.4 Noise measurement procedures

4.4.1 The microphone shall be a 12.7 mm diameter pressure type, with its protective grid, mounted in an inverted position such that the microphone diap hragm is 7 mm above and parallel to a circular metal plate. This white-painted metal plate shall be 40 cm in diameter and at least 2.5 mm thick, and shall be placed horizontally and flush with the surrounding ground surface with no cavities below the plate. The microphone shall be located three-quarters of the di stance from the centre to the edge along a radius normal to the line of flight of the test aeroplane.

4.4.2 If the noise signal is tape-recorded, the freque ncy response of the electrical system shall be determined, during each test series, at a level within 10 dB of the full-scale reading used during the tests, utilizing random or pseudorandom pink noise. The output of the noise generator shall have been checked by an approved Standards laboratory within six months of the test series, and tolerable changes in the relative output at each one-third octave band shall be not more than 0.2 dB. Sufficient determinations
shall be made to ensure that the over-all ca libration of the system is known for each test.

4.4.3 Where a magnetic tape recorder forms part of the measuring chain, each reel of magnetic tape shall carry 30 s of this electrical calibration signal at its beginning and end for this purpose. In addition, data obtained from tape recorded signals shall be accep ted as reliable only if the level difference in the 10
kHz one-third octave band filtere d levels of the two signals is not more than 0.75 dB.

Note.— Digital audio recorders typically do not exhib it substantial variation in frequency response or level sensitivity, therefore the pink noise testing described in 4.4.3 is not necessary for digital audio recorders. Design characteristics for digital aud io recorders should be compliant with class 1 performance specifications of IEC 61672-1. 1A-22

4.4.4 The A-frequency-weighted sound level of the background noise, including ambient noise and electrical noise of the measurement systems, shall be de termined in the test area with the system gain set at levels which will be used for aeroplane noise measurements. If the maximum A-frequency-weighted and S-time-weighted sound level of the aeroplane do es not exceed the A frequency-weighted sound level of the background noise by at least 10 dB, a take-off measu rement point nearer to the start of roll shall be used and the results adjusted to the refe rence measurement point by an approved method.

1 IEC 61672-1: 2002 entitled “Electroacoustics – Sound level meters – Part I: Specifications”. This IEC publication may be
obtained from the Bureau central de la Commission électro technique internationale, 1 rue de Varemb é, Geneva,
Switzerland.
2 IEC 60942: 2003 entitled “Electroacoustics – Sound calibrators”. This IEC publication may be obtained from the Bureau central de la Commission électrotechnique internationale, 1 rue de Varembé, Geneva, Switzerland.

End of new text.

5. ADJUSTMENT TO
TEST RESULTS

. . .

5.2 Corrections and adjustments

Replace the equation under the Note to 5.2.2 c) 3) as follows:

. . .

ATTACHMENT C. GUIDELINES FOR NOISE CERTIFICATION OF INSTALLED AUXILIARY POWER UNITS (APU) AND ASSOCIATED
AIRCRAFT SYSTEMS DURING GROUND OPERATION

Note.— See Part II, Chapter 9.

1. INTRODUCTION

. . .

1.2 It should apply to installed APU and associ ated aircraft systems in all aircraft for which the application for a certificate of airworthiness for the prototype Type Certificate , or another equivalent prescribed procedure, is made submitted on or after 26 November 1981. 

### c V N D

M T

R 2 / 1

2 2



### 60 ⎥ ⎥ ⎦ ⎤

⎢ ⎢ ⎣ ⎡

+ ⎟ ⎠ ⎞ ⎜ ⎝ ⎛

= πA-23

. . .

Replace Attachment E as follows:

ATTACHMENT E. APPLICABILITY OF ANNEX 16
NOISE CERTIFICATION STANDARDS FOR PROPELLER-DRIVEN AEROPLANES 1A-24

ATTACHMENT F. GUIDELINES FOR NOISE CERTIFICATION
OF TILT-ROTOR AIRCRAFT

. . .

1. APPLICABILITY

The following guidelines should be applied to all tilt -rotor aircraft, including their derived versions, for which a type certificate of airworthiness an application for Type Certificate was issued submitted on or after 13 May 1998.

. . .

ATTACHMENT H. GUIDELIN ES FOR OBTAINING HELICOPTER
NOISE DATA FOR LAND-USE PLANNING PURPOSES

. . .

2. DATA COLLECTION
PROCEDURES

2.1 Data suitable for land-use planning pur poses may be derived directly from Chapter 8 noise certification data. Chapter 8 applicants may optionally el ect to acquire data suitable for land-use planning purposes via alternative take-off, approach and/or flyover procedures defined by the applicant and approved by the certificating authority. Alternativ e flyover procedures should be performed overhead the flight path reference point at a height of 150 m. In addition, an applicant ma y optionally elect to provide data at additional microphone locations.

2.2 Chapter 11 noise certification data may be provided for land-use pl anning purposes. Chapter 11 applicants may optionally elect to provide data acqui red via alternative flyover procedures at 150 m above ground level. In acquiring data for land-use plan ning purposes, Chapter 11 applicants should give consideration to acquiring data from two additional microphones symmetrically disposed at 150 m on each side of the flight path and/ or additional take-off a nd approach procedures defined by the applicant and approved by the certificating authority. In addition, an applicant may optionally elect to provide data at additional microphone locations.

— — — — — — — —ATTACHMENT B to State letter AN 1/61.2, AN 1/62.2 - 07/34

PROPOSED AMENDMENT TO

INTERNATIONAL STANDARDS AND RECOMMENDED PRACTICES

ENVIRONMENTAL PROTECTION

ANNEX 16
TO THE CONVENTION ON INTERNATIONAL CIVIL AVIATION

VOLUME II
AIRCRAFT ENGINE EMISSIONS

1. The text of the amendment is arranged to show delete d text with a line through it and new text highlighted with grey shading, as shown below:

1. Text to be deleted is shown with a line through it. text to be deleted

2. New text to be inserted is highlighted with grey shading. new text to be inserted

3. Text to be deleted is shown with a line through it followed by the replacement text which is highlighted with grey shading. new text to replace existing textTEXT OF PROPOSED AMENDMENT TO THE

INTERNATIONAL STANDARDS
AND RECOMMENDED PRACTICES

ENVIRONMENTAL PROTECTION

ANNEX 16
TO THE CONVENTION ON INTERNATIONAL CIVIL AVIATION

VOLUME II
AIRCRAFT ENGINE EMISSIONS

. . .

PART I. DEFINITIONS AND SYMBOLS

CHAPTER 1. DEFINITIONS

. . .

Rated output thrust . For engine emissions purposes, the maximum power/thrust available for take

- off take-off thrust approved by the certificating authority for use under normal operating conditions at ISA
sea level static conditions , and without the use of water injec tion as approved by the certificating authority . Thrust is expressed in kilonewtons.

. . .

Take-off phase . The operating phase defined by the time dur ing which the engine is operated at the rated output thrust

.

. . .

CHAPTER 2. SYMBOLS

. . .

F

oo Rated output (see definition) thrust

F*

oo Rated output thrust with afterburning applied

. . .B-2

PART III. EMISSIONS CERTIFICATION

CHAPTER 1. ADMINISTRATION

. . .

1.3 The document attesting emissions certification for each individual engine shall include at least the following information which is applicable to the engine type:

. . .

d) rated output thrust ;

. . .

CHAPTER 2. TURBO-JET AND TURBOFAN ENGINES INTENDED FOR
PROPULSION ONLY AT SUBSONIC SPEEDS

. . .

2.1.4.2 Thrust settings

The engine shall be tested at sufficient power thrust settings to define the gase ous and smoke emissions of the engine so that mass emission rates and Smoke Nu mbers corrected to the reference ambient conditions can be determined at the following specific percentages of rated output thrust as agreed by the certificating authority:

LTO Operating mode Thrust setting

Take-off 100 per cent F

oo Climb 85 per cent F

oo Approach 30 per cent F

oo Taxi/ground idle 7 per cent F

oo

. . .

2.1.4.4 Fuel specifications

The fuel used during tests shall meet the specifications of Appendix 4 , unless a deviation and any necessary corrections have been agreed by the certificating authority . Additives used for the purpose of smoke suppression (such as organo-metallic compounds) shall not be present.

. . .

2.1.6 2.5.3 When test conditions differ from the reference atmospheric conditions in 2.1.4 2.1.4.1 the gaseous emission test results shall be corrected to the reference atmospheric conditions by the methods given in Appendix 3.

. . .B-3

2.2.2 Regulatory Smoke Number

The Smoke Number at any of the four LTO Operating Modes thrust setting when measured and computed in accordance with the procedures of Appendix 2 and conve rted to a characteristic level by the procedures of Appendix 6 shall not exceed the level determined from the following formula:

Regulatory Smoke Number = 83.6 ( F

oo ) –0.274
or a value of 50,
whichever is lower

2.3 Gaseous emissions

2.3.1 Applicability

The provisions of 2.3.2 shall apply to engines whose rated output thrust is greater than 26.7 kN and whose date of manufacture is on or after 1 January 1986 and as further specified for oxides of nitrogen.

2.3.2 Regulatory levels

Gaseous emission levels when measured and computed in accordance with the procedures of Appendix 3 and converted to characteristic levels by the pro cedures of Appendix 6 shall not exceed the regulatory levels determined from the following formulas:

. . .

d) for engines of a type or model for which the da te of manufacture of the first individual production
model was after 31 December 2007:

. . .

3) for engines with a pressure ratio of 82.6 or more:

D

p / F

oo = 32 + (1.6 * π oo )

Note.

— The characteristic level of the Smoke Number or gaseous pollutant emissions is the mean of the values of all the engines tested, measured a nd corrected to the reference standard engine and reference ambient conditions divided by the coefficie nt corresponding to the number of engines tested, as shown in Appendix 6.

2.4.1 General information

The following information shall be provided for each engine type for which emissions certification is sought:

a) engine identification;

b) rated output thrust (in kilonewtons);

. . .B-4

2.4.3 Derived information

. . .

2.4.3.2 The characteristic Smoke Number and ga seous pollutant emission leve ls shall be provided for each engine type for which emissions certification is sought.

Note.

— The characteristic level of the Smoke Number or gaseous pollutant emissions is the mean of the values of all the engines tested, me asured and corrected to the reference sta ndard engine and reference ambient conditions, divided by the coefficie nt corresponding to the number of engines tested, as shown in Appendix 6.

. . .

APPENDIX 2. SMOKE EMISSION EVALUATION

. . .

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 made of
stainless steel or any other non-reactive material . If a mixing probe is used, all sampling orifices shall be of equal diameter.

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

c) The number of sampling orifices locations sampled shall not be less than 12.

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

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

2.2 Sampling line for
smoke emissions

. . .

2.2.2 Sampling lines shall be as “straight throu gh” as possible. Any necessary bends shall have radii which are greater than 10 times the inside diameter of the lines. The material of the lines shall be such as to discourage build up of particulate matter or static electricity.B-5

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

2.3 Smoke analysis system

. . .

f) temperature control : the incoming analyser internal sample line through to the filter holder shall be maintained at a temperature between 60°C and 175°C with a stability of ±15°C;

Note.— The objective is to prevent water conde nsation prior to reaching the filter holder and
within it.

. . .

j) reflectometer : the measurements of the reflectance of the filter material shall be by an instrument conforming to the American National Standards Institute (ANSI) International Standards Organization, Standard No. PH2.17/1977 ISO 5.4 for diffuser diffuse reflection density. The diameter of the reflectometer light beam on the filter paper shall not exceed D/2 nor be less than D/10 where D is the diameter of filter stained spot as defined in Figure 2-1.

Replace Figure 2-1. Smoke analysis system as follows:B-6

2.5 Smoke measurement procedures

2.5.1 Engine operation

. . .

2.5.1.2 The tests shall be made at the power thrust settings approved by the certificating authority. The engine shall be stabilized at each setting.

2.5.2 Leakage and cleanliness checks

. . .

a) leakage check : isolate probe and close off end of sample line, perform leakage test as specified in 2.3 g) h) with the exceptions that valve A is opened and set to “bypass”, valve D is closed and that the leakage limit is 2 L. Restore probe and line interconnection;

. . .

2.5.3 Smoke measurement

. . .

b) set valve A to “bypass”, close valve D and clam p clean filter into holder. Continue to draw exhaust sample in the bypass setting for at least five minutes while the engine is at or near to the requisite operating mode required operating condition , valve C being set to give a flow rate of 14 ±0.5 L/min;

. . .

APPENDIX 3. INSTRUMENTATION AND MEASUREMENT TECHNIQUES
FOR GASEOUS EMISSIONS

. . .

3. DATA REQUIRED

3.1 Gaseous emissions

Concentrations of the following emissions shall be determined:

a) Hydrocarbons (HC): a combined estimate of all hydro-carbon compounds present in the exhaust

gas.

b) Carbon monoxide (CO).

c) Carbon dioxide (CO 2 ).

Note.— CO 2 is not considered a pollutant a regulated engine emission but its concentration is required for calculation and check purposes.B-7

. . .

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 made of stainless steel. If a mixing probe is used, all sampling orifices shall be of equal diameter or any other non-reactive metal ;

b) the if a probe with multiple sample orifices is used, all sampling orifices shall be of equal
diameter. 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;

c) the number of sampling orifices locations sampled shall not be less than 12;

. . .

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

. . .

6. GENERAL TEST PROCEDURES

6.1 Engine operation

. . .

6.1.2 The emissions tests shall be made at the power thrust settings prescribed by the certificating authority. The engine shall be stabilized at each setting.

. . .

6.3 Operation

. . .

6.3.2 The following procedure shall be adopted for operational measurements:

. . .

c) when the engine has been stabilized at the requi site operating mode required thrust setting

, continue to run it and observe pollutant concen trations until a stabilized reading is obtained, which shall be recorded;

. . .B-8

7. CALCULATIONS

7.1 Gaseous emissions

7.1.1 General

The analytical measurements made shall be the con centrations of the various classes of pollutant, as detected at their respective analy sers for the several engine operation modes, and these values shall be reported. In addition, other parameters shall be computed and reported, a s follows**. gaseous emissions, as detected at their respective analysers fo r a range of combustor inlet temperatures (T B ) encompassing the four LTO operating modes. Using the calculations of 7.1.2, or the alternative methods defined in Attachment E to this appendix, the measured emi ssions indices (EI) for each gaseous emission shall be
established. To account for deviations from referen ce atmospheric conditions, the corrections of 7.1.3 shall be applied. Note that these corrections may also be used to account for deviations of the tested engine from the reference standard engine where appropriate (see Appendix 6, paragraph 1 f)). Using combustor inlet temperature (T B ) as a correlating parameter, the emissions indices and fuel flow corresponding to operation at the four LTO operati ng modes of a reference standard engine under reference day conditions sh all then be established using the procedures of 7.2.

7.1.2 Basic parameters

where

2 Z

– ( n/m ) P 0 / m = 4(1 + h

– | TZ /2 | )

2 Z – ( n/m ) P 0 / m = 4(1 + h vol – [ TZ /2])

and

2

– [CO]

– ( | 2/ x |

 –

 | y / 2x | ) [HC} + [NO 2 ] Z

= [CO 2 ] + [CO] + [HC]

2 – [CO] – ([2/ x ]

 –

 [ y / 2x ]) [HC] + [NO 2 ] Z

= [CO 2 ] + [CO] + [HC]

. . .

η efficiency of NO 2 /NO converter

h vol humidity of ambient air, vol water/vol dry air

. . .B-9

7.1.3 Correction of emission indices
to reference conditions

Corrections shall be made to the me asured engine emission indices for all pollutants in all relevant engine operating modes to account for deviations from the reference atmospheric conditions (ISA at sea level) of the actual test inlet air conditions of temperature and pressure. These corrections may also be used to account for deviations of the tested engine from th e reference standard engi ne where appropriate (see Appendix 6, paragraph 1 f)). The reference value for humidity shall be 0.00634 kg water/kg dry air.

Thus, EI corrected = K × EI measured,

where the generalized expression for K is:

K = (P B ref /P B ) a × (FAR ref /FAR B ) b × exp ( |T B ref – T B |/ c ) × exp ( d | h

– 0.00634| )

K

= (P B ref /P B ) a × (FAR ref /FAR B ) b × exp ( [T B ref – T B ]/ c ) × exp ( d [ h

mass – 0.00634] )

. . .

h

mass Ambient air humidity , kg water/kg dry air

. . .

7.1.4 Using the recommended curve fitting technique of paragraph 7.2 to relate emission indices to combustor inlet temperature effectively eliminates the exp ((T B ref – T B )/ c ) term from the generalized equation and for most cases the ( FAR ref / FAR B ) term may be considered unity. For the emissions indices of CO and HC many testing facilities have determined th at the humidity term is sufficiently close to unity to be eliminated from the expression and that the exponent of the ( P B ref /

P B ) term is close to unity.

. . .

EI(NO

x ) corrected = EI derived from EI(NO

x ) ( P B ref /

P B ) 0.5 exp (19 | h

– 0.00634 | ) v. T B curve

EI(NO

x ) corrected = EI derived from EI(NO

x ) ( P B ref /

P B ) 0.5 exp (19 [ h

mass – 0.00634 ] ) v. T B curve

. . .

7.2 Control parameter functions ( D

p , F

oo , π )

7.2.1 Definitions

. . .

F

oo The maximum thrust available for take

- off under normal operating c onditions at ISA sea level
static cond itions, without the use of water injection, as approved by the applicable certificating authority. Rated thrust (see definition)B-10

F

n Thrust at LTO operating mode, n. (kN)

W

f Fuel mass flow rate of the reference standa rd engine under ISA sea level conditions. (kg/s)

W

f n Fuel mass flow rate of the reference standa rd engine under ISA sea level conditions at LTO operating mode, n.

π The ratio of the mean total pressure at the last compressor discharge plane of the compressor to the mean total pressure at the compressor entry plane when the engine is developing take-off thrust rating at ISA sea level static conditions.

7.2.2 The emission indices (EI) for each pollu tant, corrected for pressure and humidity (as appropriate) to the reference ambient atmospheric conditions as indicated in 7.1.4 and

, if necessary

, to the
reference standard engine, EI (corrected), shall be obtained for the required each LTO engine operating mode settings ( n ) of idle, approach, climb

- out and take

- off, at each of the equivalent corrected thrust
conditions . A minimum of three test points shall be requi red to define the idle mode. The following relationships shall be determined under reference atmospheric conditions for each pollutant gaseous emission :

a) between EI (corrected) and T B ; and

b) between W f (engine fuel mass flow rate) and T B ; and

c) between F

n (corrected to ISA sea level conditions) F and T B (corrected to ISA sea level conditions) ;

Note 1 .— These are illustrated, for example, by Figure 3-2 a), b) and c).

Note 2.— The relationships b) and c) may be estab lished directly from engine test data, or may be derived from a validated engine performance model.

When the engine being tested is not a “reference” engine, the data may be corrected to “reference” engine conditions using the relations hips b) and c) obtained from a refe rence engine. A reference engine is defined as an engine substantially c onfigured to the description of the engine to be certificated and accepted by the certificating authority to be representa tive of the engine type for which certification is sought. A reference engine is defined as an engine substa ntially configured to the production standard of the engine type and with fully representative operating and performance characteristics.

The manufacturer shall also supply to the certif icating authority all of the necessary engine performance data to substantiate these relations hips and for ISA sea level ambient conditions:

d) maximum rated thrust ( F

oo ); and

e) engine pressure ratio ( π ) at maximum rated thrust.

Note.— These are illustrated by Figure 3-2 d).

7.2.3 The estimation of EI (corrected) for each pollutant at each of the required engine mode settings, corrected to the reference ambient condition s , gaseous emission at the four LTO operating modes shall comply with the following general procedure:B-11

a) at each mode ISA thrust condition F

n , determine the equivalent combustor inlet temperature ( T B ) (Figure 3-2 c)) at the values of F

n corresponding to the four LTO operating modes,

n , under reference atmospheric conditions ;

b) from the EI (corrected) / T B characteristic (Figure 3-2 a)), determine the EI

n value corresponding to

T

B ;

c) from the W f / T B characteristic (Figure 3-2 b)), determine the W f n value corresponding to T B ;

. . .

ATTACHMENT E TO APPENDIX 3. THE CALCULATION OF THE EMISSIONS PARAMETERS — BASIS, MEASUREMENT CORRECTIONS AND
ALTERNATIVE NUMERICAL METHOD

Editorial Note.— Replace straight brackets and use vol .– index for humidity.

1. SYMBOLS

. . .

h vol humidity of ambient air, vol water/vol dry air

. . .

2. BASIS OF CALCULATION OF EI
AND AFR PARAMETERS

2.1 It is assumed that the balance between the orig inal fuel and air mixture and the resultant state of the exhaust emissions as sampled can be represented by the fo llowing equation:

CmHn + P0[R(O2) + S(N2) + T(CO2) + h vol (H2O)]

= P1(CO2) + P2(N2) + P3(O2) + P4(H2O)

+ P5(CO) + P6(CxHy) + P7(NO2) + P8(NO)

from which the required parameters can, by definition, be expressed as

. . .

2.3 The ambient air humidity, h vol , is as measured at each test condition. It is recommended that, in the absence of contrary evidence as to the characterization (x, y) of the exhaust hydrocarbon, values of x = 1 and y = 4 are assigned.

2.4 Determination of the remaining unknowns requires the solution of the following set of linear simultaneous equations, where (1) to (4) derive from the fundamental atomic conservation relationships and (5) to (9) represent the gaseous product concentration relationships.

m + TP0 = P1 + P5 + xP6 .......................................................................... (1)B-12

n + 2h vol P0 = 2P4 + yP6 ............................................................................. (2)

(2R + 2T + h vol )P0 = 2P1 + 2P3 + P4 + P5+ 2P7 + P8 .......................................................... (3)

. . .

3. ANALYTICAL FORMULATIONS

. . .

3.2 Equation for conversion of dry concentration measurements
to wet basis

Concentration wet = K × concentration dry; that is,

[ ] = K [ ] d

The following expression for K applies when CO and CO 2 are determined on a “dry” basis:



## { 4 +( n/m ) T + ( | n/m| T

− 2 h ) 

## ( [NO 2 ]

− (2[HC]/ x ) 

## )
K

= (2 + h ) 

## { 2 + ( n/m ) (1 + h d ) 

## ( [CO 2 ] d + [CO] d 

## ) }

+ (2 + h ) (| y/x |

− | n/m |) [HC] 

## } (1 + h d )

− (| n/m | T

− 2 h ) 

## ( 1

− |1 + h d |[CO] d 

## )

{ 4 + ( n/m ) T + ([ n/m ] T

− 2 h vol ) 

## ( [NO 2 ]

− (2[HC]/ x ) 

## )
K

= (2 + h ) 

## { 2 + ( n/m ) (1 + h d ) 

## ( [CO 2 ] d + [CO] d 

## ) }

+ (2 + h vol ) ([ y/x ]

− [ n/m ]) [HC] 

## } (1 + h d )

− ([ n/m ] T

− 2 h ) 

## ( 1

− [1 + h d ] [CO] d 

## )

. . .

3.4 Equation for estimation of sample water content

Water concentration in sample

(| n/ 2 m | + h | P 0 /m |) ([CO 2 ] + [CO] + [HC]) [H 2 O] = 1 + T (P

o / m ) − ( y/

2

x ) [HC]

([ n/ 2 m ] + h vol [ P 0 /m ]) ([CO 2 ] + [CO] + [HC]) [H 2 O] = 1 + T (P

o / m ) − ( y/

2

x ) [HC]

whereB-13

2Z

− ( n/m ) P 0 / m = 4(1 + h

− | TZ /2|)

2Z

− ( n/m ) P 0 / m = 4(1 + h vol − [ TZ /2])

and

2

− [CO]

− (|2/ x |

− | y/2x |) [HC] + [NO 2 ] Z

= [CO 2 ] + [CO] + [HC]

2

− [CO]

− ([2/ x ]

− [ y/2x ]) [HC] + [NO 2 ] Z

= [CO 2 ] + [CO] + [HC]

It should be noted that this estimate is a function of the various analyses concentration readings, which may them-selves require water interference corr ection. For better accuracy an iterative procedure is required in these cases with successive recalculation of the water concentration until the requisite stability is obtained. The use of the alternative, numeri cal solution methodology (4) avoids this difficulty.

. . .

APPENDIX 6. COMPLIANCE PROCEDURE FOR
GASEOUS EMISSIONS AND SMOKE

. . .

2. COMPLIANCE PROCEDURES

The certificating authority shall award a certificate of compliance if the mean of the values measured and corrected (to the reference standa rd engine and reference ambient atmospheric conditions) for all the engines tested, when converted to a characteristic leve l using the appropriate fact or which is determined by the number of engines tested ( i ) as shown in the table below, does not exceed the regulatory level.

Note.— The characteristic level of the Smoke Number or gaseous pollutant emissions is the mean of the values of all the engines tested, measured and , for gaseous emissions only, appropriately corrected to the reference standard engine and reference ambient conditions atmospheric conditions, divided by the coefficient corresponding to the number of engin es tested, as shown in the table below.

. . .

— — — — — — — —ATTACHMENT C to State letter AN 1/61.1, AN 1/62.2 – 07/34

RESPONSE FORM TO BE COMPLETED AND RETURNED TO ICAO TOGETHER
WITH ANY COMMENTS YOU MAY HAVE ON THE PROPOSED AMENDMENTS

To: The Secretary General International Civil Aviation Orga nization 999 University Street Montreal, Quebec Canada, H3C 5H7

(State)

Please make a checkmark ( 9 ) against one option for each amendmen t. If you choose options “agreement with comments” or “disagreement with comments”, please provide your comments on separate sheets

.

Agreement

without

comments Agreement
with

comments* Disagreement
without

comments Disagreement
with

comments No position

Amendment to Annex 16 — Environmental Protection

, Volume I — Aircraft Noise (Attachment A refers)

Amendment to Annex 16 — Environmental Protection

, Volume II — Aircraft Engine Emissions (Attachment B refers)

*“Agreement with comments” indicates that your State or organization agrees with the intent and overall thrust of the amendment proposal; the comments th emselves may include, as necessary, your reservations concerning certain parts of the proposal and/or offer an alternative proposal in this regard.

Signature: Date:

— END —