AC 34-1B

Advisory U.S. Department of Transportation Federal Aviation CircularAdministration Subject: FUEL VENTING AND EXHAUST

EMISSION REQUIREMENTS Date:

Initiated by:

06/27/03 AEE-300 AC No:

Change:

34–1B

FOR TURBINE ENGINE

POWERED AIRPLANES

1. PURPOSE The intent of this advisory Circular (AC) is to promote uniformity of implementation of the emissions certification requirements of Part 34 of the Federal Aviation Regulations. FAR 34 is unusually complex in that it must reflect the requirements of the Clean Air Act, Sections 232 and 233, the EPA, 40 CFR Part 87 and ICAO Annex 16, Volume II, Second Edition, July 1993, as well the FAA’s mandated charter. This advisory circular brings these seemingly disparate requirements together to provide a single source of information and advice to individuals and agencies interested in FAR 34.

a. Contents This revised Advisory Circular (AC) contains updated information, including anticipated adoption of ICAO CAPE 4 post December 31, 2003 rules, describing the standards and requirements for aircraft fuel venting and engine emission certification and presents explanatory and supplementary information, as necessary, to identify acceptable means of compliance. The information contained in this document sets forth acceptable means, but not the sole means, by which compliance may be shown with the requirements of Federal Aviation Regulations (FAR) Part 34 of the United States Code of Federal Regulations (CFR) Title 14. The regulation that this AC references is 14 CFR Part 34 and its Amendments (hereinafter referred to as “Part 34”).

Pursuant to the Clean Air Act (CAA), Sections 231 and 232, Part 34 necessarily must conform to Environmental Protection Agency (EPA) Title 40, Part 87, “Control of Air Pollution From Aircraft and Aircraft Engines; Emission Standards and Test Procedures”. Therefore any change in procedures, of a substantive nature, must be discussed with, and approved by, the Administrator of the EPA. This is mentioned explicitly in Part 34 and in this AC for those areas of particular concern. In addition, users of this AC, as well as Part 34, must be aware of any changes to 40 CFR Part 87 which have not yet been included in either Part 34 or this AC. In such instances the requirements described in these documents must defer to 40 CFR Part 87, unless and until approval is obtained from the Administrator of the EPA.

b. Advisory Nature Like other Federal Aviation Administration (FAA) advisory circulars, the language within this document is intended to be permissive and advisory in nature, except for explanations of regulatory language that are mandatory. In addition, the compliance methods chosen by the applicant are voluntary within the framework of the regulation as written. Mandatory terms used in this AC, such as “must” and “shall”, are used only in the sense of ensuring the applicability of these particular methods of compliance when the acceptable means of compliance described herein are used. This AC does not change regulatory requirements and does not authorize changes in, or deviations from, regulatory requirements.

c. Document Format This AC contains a section-by-section review and explanation of 14 CFR Part 34. In order to assist the user, each explanation is provided as a separate, sequentially numbered, paragraph. In general, each paragraph is presented as follows in Figure 1:

Paragraph Number: 1. Citation Number: Number in 14 CFR Part 34 that Easy to reference is being addressed number for each section of Advisory Circular AC 34-1B that is addressed Actual regulatory text (italicized and indented) reproduced for better readability) 19 § 34.61 Turbine Fuel Specification For exhaust emissions testing, fuel meeting the specifications listed below shall be used…

a. Explanation The fuel specification in Part 34 matches the amended ICAO fuel specification in Annex 16, Vol. II, Second Edition, 1993. This specification is typical of Jet A

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

2. DEFINITIONS Where the following expressions are used in this appendix, they have the meanings ascribed to them below:

(1) Accuracy . The closeness with which a measurement approaches the true value established independently.

Brief “Plain English” explanation of regulatory text (appears only if text is not self explanatory) Potentially useful supplementary information (included only if necessary) Text reproduced from ICAO Annex 16, Volume II, Second Edition, 1993.

FIGURE 1: Document Format In addition to the section-by-section explanations, this AC includes 3 additional chapters that explain specific appendices from ICAO, Annex 16, Volume II. Second Edition, July 1993. These have been included to make this AC relatively self contained, since these appendices are explicitly referenced within Part 34. Specifically:

• FAR 34 Subpart G refers to ICAO Appendices 3, 5 and 6.

• FAR 34 Subpart H refers to ICAO Appendices 2 and 6.

These ICAO appendices, 3,5 and 6, deal with detailed technical issues regarding instrumentation and measurement techniques and statistically derived compliance procedures. As such they are relatively complex and have been kept distinct from the rest of the AC as separate chapters. Typically, only those readers who are interested in specific equations and/or details regarding measurement techniques and compliance procedures will need to read these sections.

d. Audience The intended audience for this AC includes engine specialists from the FAA (aircraft certification and flight standards), aircraft and aircraft engine industry, aircraft certification applicants, foreign governments, airline customers, airport operators, the scientific community, and other interested persons.

e. AC Intent The intent of this AC is to establish a clear understanding between the regulatory authorities, aircraft engine users, local governments, and the aircraft engine industry of the engine emissions certification processes and to present historical policies, guidance material and interpretations that have been used in the aircraft engine certification process.

f. Document Use Sequential paragraphs are indicated in this AC to improve usage. The regulatory section numbers, together with the regulatory language are indented and italicized. In addition, text from ICAO Annex 16 is included (shaded and italicized) where appropriate.

g. Technical Advancement:

Since the introduction of engine emission standards in 1973 (38 FR 19088, July 17, 1973), acceptable means and procedures for measurement, testing, data reduction, evaluation and compliance reporting have advanced considerably. For the purpose of certification and compliance, applicants have, over time, developed, evaluated and had approved engine specific alternate but equivalent testing, measurement and data reduction procedures. Approval, in these instances, is obtained through the FAA, Office of Environment and Energy (AEE) located in the FAA Headquarters in Washington DC.

h. FAA Certification Process:

The FAA administrative certification process is shown in Figure 2. Each step in the appropriate process must be completed before proceeding to the next step. Specific details of this process can be found in a memorandum “Inter-Office Management Plan for Aircraft Engine Fuel Venting and Exhaust Emissions”, appended to this Advisory Circular as Exhibit 1. As a part of its compliance responsibilities, FAA can either conduct the emission tests or delegate that responsibility to the engine manufacturer, which is then monitored by the FAA. Since the FAA does not have the reso urces or the funding to test engines themselves, FAA selects engineers at each plant to serves as representatives (called Designated Engineering Representatives or DERs) for the FAA while the manufacturer performs the test procedures. DER’s responsibilities include evaluating the test plan, the test engine, the test equipment, and the final testing report sent to the FAA.

i. Exclusions There are no sections excluded from this AC.

2. CANCELLATION Advisory Circular 34–1A, Fuel Venting and Exhaust Emission Requirements for Turbine Engine Powered Airplanes, dated June 30, 2001, is canceled.

FAA Certification Process (Administrative) New Model Certification Major Change Substantiation Preliminary Type

Board with FAA

Overall Test Plan/

Analysis

Outline to FAA

Detailed Test Plans to FAA Test Plan Approved by FAA FAA Final Type

Board Meeting

Analysis to FAA AND/OR Analysis Approved by FAA Test Plan Analysis ORSubmitted to FAA Submitted to FAA Test Plan Analysis

Approved by FAA Approved by FAA

Major Change Approved by FAA Results Submitted to FAA Test Conformity

Inspection

Conformity

Inspection

Test Post Test

Inspection

Test Report Approved

DER Responsible to local region FIGURE 2. FAA Certification Process Page 4

3. TABLE OF CONTENTS

1. PURPOSE1

a. Contents1

b. Advisory Nature1

c. Document Format1

d. Audience3

e. AC Intent3

f. Document Use3

g. Technical Advancement:3

h. FAA Certific ation Process:3

FAA Certification Process - Figure 24

i. Exclusions3

2. CANCELLATION3

3. TABLE OF CONTENTS5

4. REFE RENCES7

I. 14 CFR PART 34 Subpart A—General Provisions7

5. §34.1 DEFINITIONS7

6. §34.2 Abbr evations10

7. § 34.3 GENERAL REQUIREMENTS12

8. §34.4 [RESERVED]17

9. §34.5 SPECIAL TEST PROCEDURES17

10. §34.6 AIRCRAFT SAFETY18

11. §34.7 EXEMPTIONS18

II. Subpart B — Engine Fuel Venting Emissions - (New and In-Use Aircraft Gas Turbine

Engines)21

12. §34.10 APPLICABILITY21

13. §34.11 STANDARD FOR FUEL VENTING EMISSIONS21

III. Subpart C — Exhaust Emissions (New Aircraft Gas Turbine Engines)23

14. § 34.20 APPLICABILITY23

15. § 34.21 STANDARDS FOR EXHAUST EMISSIONS23

IV. Subpart D — Exhaust Emissions (In-Use Aircraft Gas Turbine Engines)Error! Bookmark not defined.

16. § 34.30 APPLICABILITY27

17. § 34.31 STANDARDS FOR EXHAUST EMISSIONS27

V. Subpart E — [Reserved]28

VI. Subpart F — [Reserved]29

VII. Subpart G — Test Procedures for Engine Exhaust Gaseous Emissions (Aircraft and

Aircraft Gas Turbine Engines)30

18. §34.60 INTRODUCTION30

19. §34.61 TURBINE FUEL SPECIFICATION30

20. §34.62 TEST PROCEDURE (PROPULSION ENGINES)32

21. §34.63 [RESERVED]33

22. §34.64 SAMPLING AND ANALYTICAL PROCEDURES FOR MEASURING GASEOUS EXHAUST EMISSIONS33

23. §34.65—§34.70 [RESERVED]33

24. § 34.71 COMPLIANCE WITH GASEOUS EMISSION STANDARDS33

VIII. Subpart H — Test Procedures for Engine Smoke Emissions (Aircraft and Aircraft Gas

Turbine Engines)33

25. §34.80 INTRODUCTION34

26. §34.81 FUEL SPECIFICATIONS35

27. §34.82 SAMPLING AND ANALYTICAL PROCEDURES FOR MEASURING - SMOKE EXHAUST EMISSIONS36

28. §34.83 – §34.88 [RESERVED]36

29. §34.89 COMPLIANCE WITH SMOKE EMISSION STANDARDS36

IX. ICAO ANNEX 16, VOLUME II, Second Edition, July, 1993, APPENDIX 638

X. ICAO ANNEX 16, VOLUME II, Second Edition, July, 1993, APPENDIX 342

XI. ICAO ANNEX 16, VOLUME II, Second Edition, July, 1993, APPENDIX 581

XII. ICAO ANNEX 16, VOLUME II, Second Edition, July, 1993, APPENDIX 2121

30 EXHIBIT 1 Inter-O ffice Management Plan131

4. REFERENCES

(1) Clean Air Act as amended, 42 U.S.C. 7571 and 7601.

(2) 14 CFR ch. 1 (1-1-97 edition), Federal Aviation Administration, Department of Transportation, Subchapter A, Definitions.

(3) 40 CFR Part 87, Environmental Protection Agency, Control of Air Pollution from Aircraft and Aircraft Engines; Emission Standards and Test Procedures; Final and Proposed Rule, Federal Register, Vol. 62, No. 89, Thursday, May 8, 1997.

(4) Federal Aviation Regulations, Part 34, Fuel Venting and Exhaust Emission Requirements for Turbine Engine Powered Airplanes, February 3, 1999.

(5) International Civil Aviation Organization, International Standards and Recommended Practices, Environmental Protection, Annex 16, Volume II, Aircraft Engine Emissions, Second Edition — July 1993.

(6) SAE International, SAE AEROSPACE RECOMMENDED PRACTICE ARP 1256, Procedure for the Continuous Sampling and Measurement of Gaseous Emissions from Aircraft Turbine Engines.

(7) SAE International, SAE AEROSPACE RECOMMENDED PRACTICE ARP 1179, Aircraft Gas Turbine Engine Exhaust Smoke Measurement.

(8) SAE International, SAE AEROSPACE RECOMMENDED PRACTICE ARP 1533, Procedure for the Calculation of Gaseous Emissions from Aircraft Turbine Engines.

I. 14 CFR 34 Subpart A General Provisions

5. 34.1 Definitions As used in this AC, all terms not defined herein shall have the meaning given them in the Clean Air Act, as amended (42 U.S.C. 7401 et. seq.):

Supplemental Information:

Section 232 of the Clean Air Act, as amended, directs the Secretary of Transportation to issue regulations to ensure compliance with 40 CFR part 87. 40 CFR part 87 calls out, by reference, specific sections of ICAO Annex 16, Volume II, Second edition, 1993. ICAO A nnex 16 includes definitions which should be added to the definitions in Part 34 to provide understanding and completeness. Following is a combined list of definitions required when fulfilling the requirements of Part 34. The ICAO definitions are italicized and shaded. Some discussion is provided where further clarification is needed.

Act means the Clean Air Act, as amended (42 U.S.C. 7401 et. seq.).

Administrator means the Administrator of the Federal Aviation Administration or any person to whom he has delegated his authority in the matter concerned.

Administrator of the EPA means the Administrator of the Environmental Protection Agency and any other officer or employee of the Environmental Protection Agency to whom the authority involved may be delegated.

Aircraft as used in this part means any airplane as defined in 14 CFR part 1 for which a U.S. standard airworthiness certificate or equivalent foreign airworthiness certificate is issued.

Aircraft engine means a propulsion engine which is installed in, or which is manufactured for installation in, an aircraft.

Supplemental Information: This definition applies to those engines for which a U.S. standard airworthiness certificate or equivalent foreign airworthiness certificate is issued.

Aircraft gas turbine engine means a turboprop, turbofan, or turbojet aircraft engine.

Explanation:

As with the overall intent of this regulation piston engines are excluded.

Afterburning. A mode of engine operation wherein a combustion system fed (in whole or part) by vitiated air is used.

Approach Phase. The operating phase defined by the time during which the engine is operated in the approach operating mode.

Class TP means all aircraft turboprop engines.

Class TF means all turbofan or turbojet aircraft engines or aircraft engines designed for applications that otherwise would have been fulfilled by turbojet and turbofan engines except engines of class T3, T8, and TSS.

Explanation:

Applications, which could fulfill these requirements, are propfans, unducted fans, and advanced unducted fans.

Class T3 means all aircraft gas turbine engines of the JT3D model family.

Class T8 means all aircraft gas turbine engines of the JT8D model family.

Class TSS means all aircraft gas turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds.

Climb phase: The operating phase defined by the time during which the engine is operated in the climb operating mode.

Commercial aircraft engine means any aircraft engine used or intended for use by an "air carrier" (including those engaged in "intrastate air transportation") or a "commercial operator" (including those engaged in "intrastate air transportation") as these terms are defined in the Federal Aviation Act and the Federal Aviation Regulations.

Commercial aircraft gas turbine engine means a turboprop, turbofan, or turbojet commercial aircraft engine.

Date of manufacture of an engine is the date the inspection acceptance records reflect that the engine is complete and meets the FAA approved type design.

Emission measurement system means all of the equipment necessary to transport the emission sample and measure the level of emissions. This includes the sample system and the instrumentation system.

Explanation:

The intention is to delineate all of the equipment and devices to extract, transport, condition, differentiate and measure the concentrations of “exhaust emissions” – see 4.a. (17). If inlet species are measured, for monitoring or corrections, as part of the certification process the equipment and devices used should be included as part of the “Emissions measurement system”.

Engine model means all commercial aircraft turbine engines, which are of the same general series, displacement, and design characteristics and are approved under the same type certificate.

Supplemental Information:

For the purposes of a working definition, with respect to emissions certification, when considering the similarity or equivalence of engines, similar or equivalent engine models should be taken as those engines approved under the same type certificate. For example, from 14 CFR ch. 1 (1-1-97 edition), Federal Aviation Administration Department of Transportation, Subchapter A, Definitions: “Type”: (3) As used with respect to the certification of aircraft engines means those engines which are similar in design. For example, JT8D and JT8D-7 are engines of the same type, and JT9D-3A and JT9D-7 are engines of the same type.

Exhaust emissions means substances emitted into the atmosphere from the exhaust discharge nozzle of an aircraft or aircraft engine.

Fuel venting emissions means raw fuel, exclusive of hydrocarbons in the exhaust emissions, discharged from aircraft gas turbine engines during all normal ground and flight operations.

In-use aircraft gas turbine engine means an aircraft gas turbine engine, which is in service.

New aircraft turbine engine means an aircraft gas turbine engine, which has never been in service.

Explanation:

This definition should be viewed with respect to “In-use aircraft gas turbine engine” and relative to the intent of 40 CFR Part 87, Subpart B, Engine Fuel Venting emissions (New and In-Use Aircraft Gas Turbine Engines), Subpart C, Exhaust Emissions (New Aircraft Gas Turbine Engines), and Subpart D, Exhaust Emissions (In- Use Aircraft Gas Turbine Engines).

Any engine intended for revenue service but which has never been in service is by definition new and must meet the provisions of Subpart B and C for fuel venting, gaseous and smoke emissions. This sets the baseline for regulation and control of emissions from aircraft gas turbine engines. Alternatively the definition for in-use aircraft gas turbine engines is intended, for those engines in service, to prevent deterioration of fuel venting and/or smoke emissions beyond the maximum allowable for new engines. In other words, the first time a particular engine sees revenue service it is “new” and ever after it is “in-use”. The fact that a given engine model is in revenue service does not relieve a newly manufactured engine of this model of being considered as “new”. Although this interpretation could impose severe penalties on the engine manufacturer in the demonstration of compliance, the allowance, and universal use, of ICAO Annex 16, Volume II, Appendix 6, Compliance Procedure for Gaseous Emissions and Smoke solves the problem by specifying a limited engine preproduction compliance procedure which relieves the manufacturer from having to test every engine and, in effect, follows the engine in time, i.e., there is no requirement for the testing of engines in-use.

Oxides of Nitrogen. The sum of the amounts of the nitric oxide and nitrogen dioxide contained in a gas sample calculated as if the nitric oxide were in the form of nitrogen dioxide.

Power Setting: means the power or thrust output of an engine in terms of kilonewtons thrust for turbojet and turbofan engines or shaft power in terms of kilowatts for turboprop engines.

Rated Output (rO): means the maximum power/thrust available for takeoff at standard day conditions as approved for the engine by the Federal Aviation Administration, including reheat contribution where applicable, but excluding any contribution due to water injection and excluding any emergency power/thrust rating.

Explanation:

For the purpose of this regulation “maximum power/thrust available for takeoff” is taken to mean under normal operating conditions. The definition as stated has caused some confusion because of a maximum thrust emergency rating even though the definition, as it appears in 14 CFR Part 34, excludes any emergency power/thrust rating. Some of the confusion may be du e to the parent definition in 40 CFR 87, which does not explicitly exclude the emergency power/thrust rating. The intent is clear however from 40 CFR Part 87, Subpart G, 87.60 (c): “… determine mass emissions through calculations during a simulated aircraft landingtakeoff cycle (LTO). The LTO cycle is based on time in mode data during high activity periods at major airports.” The use of emergency power/thrust during takeoff would be an extraordinary and abnormal situation. Further, 40 CFR Part 87 (87.64) requires the use of ICAO Annex 16, Volume II, 1993, Appendix 3.

Appendix 3 defines Rated Output, rO, as “ F00,” which is further defined as: “The maximum thrust available for take-off under normal operating conditions at ISA sea level static conditions, without the use of water injection, as approved by the applicable certificating authority”.

Rated pressure ratio (rPR): means the ratio between the combustor inlet pressure and the engine inlet pressure achieved by an engine operation at rated output.

REFERENCE DAY CONDITIONS: MEANS THE REFERENCE AMBIENT CONDITIONS TO WHICH THE GASEOUS EMISSIONS (HC AND SMOKE) ARE TO BE CORRECTED. T HE REFERENCE DAY CONDITIONS ARE AS FOLLOWS: T EMPERATURE = 15 O C, SPECIFIC HUMIDITY = 0.00629 KG H20/KG OF DRY AIR, AND PRESSURE = 101325 PA.

Reference pressure ratio. 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 in ISA sea level static conditions.

Sample System: means the system, which provides for the transportation of the gaseous emissions sample from the sample probe to the inlet of the instrumentation system.

Supplemental information:

A ‘Sample System’ is required for smoke emissions as well as for gaseous emission. Detailed specifications, for each, are described in ICAO Appendices 2 and 3. There are differences in requirements between the two systems but it is not unusual to satisfy the separate requirements with an appropriately designed single sample system.

Shaft Power: means only the measured shaft power out put of a turboprop engine.

Smoke: means the matter in exhaust emissions, which obscures the transmission of light.

Smoke Number (SN): means the dimensionless term quantifying smoke emissions.

Standard day conditions: means standard ambient conditions as described in the United States Standard Atmosphere 1976, (i.e., temperature = 15 o C, specific humidity = 0.00 kg H20/kg dry air, and pressure = 101325 Pa.)

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

Taxi/idle (in): means those aircraft operations involving taxi and idle between the time of landing roll-out and final shutdown of all propulsion engines.

Taxi/idle (out): means those aircraft operations involving taxi and idle between the time of initial starting of the propulsion engine(s) used for the taxi and the turn onto the duty runway.

j. Unburned hydrocarbons. The total of hydrocarbon compounds of all classes and molecular weghts contained in a gas sample, calculated as if the were in the form of methane.

6. §34.2 Abbreviations The abbreviations used in this part have the following meanings in both upper and lower case CO Carbon Monoxide EPA United States Environmental Protection Agency FAA Federal Aviation Administration, United States Department of Transportation HC Hydrocarbons

HP Horsepower

hr Hour(s) H2O water kg Kilogram(s) kJ Kilojoule(s) LTO Landing and takeoff min Minute(s) Page 10

NO(X) Oxides of Nitrogen Pa Pascal(s) rO Rated Output rPR Rated pressure ratio sec Second(s) SP Shaft power SN Smoke number T Temperature, degrees Kelvin TIM Time in mode W Watt(s) Deg. C Degrees Celsius % Percent Supplemental information:

In addition to the abbreviations listed in §34.2 there are a large number of abbreviations from other sources that are used in AC 34. Those abbreviations listed in ICAO Annex 16 as Symbols are italicized and shaded.

Only those Symbols from ICAO that are not duplicated in Part 34 are listed.

AC FAA Advisory Circular ACO Local FAA Aircraft Certification Office AEE FAA Office of Environment and Energy AFM Airplane Flight Manual APP Approach APU Auxiliary Power Unit ARP Aerospace Recommended Practice CAA Clean Air Act CFR Code of Federal Regulations CI Confidence Interval (90%) CO2 Carbon Dioxide Dp The mass of any gaseous pollutant emitted during the reference emissions landing and take-off cycle DER Designated Engineering Representative EPA United States Environmental Protection Agency.

EI Emission Index

EPR Engine Pressure Ratio (Power Setting Parameter) Fn Thrust in International Standard Atmosphere (ISA), sea level conditions, for the given operating mode F00 Rated output F*00 Rated output with afterburning applied FAR Federal Aviation Regulation (CFR Title 14) FCAA Foreign Civil Aviation Authority FID Flame Ionization Detector FPR Fan Pressure Ratio ICAO International Civil Aviation Organization JAA Joint Airworthiness Authorities (of Europe) JAR Joint Airworthiness Requirements (of Europe) Log logarithmic value to base 10 M meter MJ Mega Joules MSL Mean Sea Level altitude, feet N/A Not Applicable NIST National Institute of Standards and Technology NO Nitric oxide NO2 Nitrogen dioxide ppmC Parts per million carbon ref. Reference RH Relative Humidity, % Page 11

rms root-mean-square rpm Revolutions Per Minute SAE SAE International (formerly Society of Automotive Engineers) Sec Second(s) TC Type Certificate TIM Time in mode TO Takeoff VNTSC Volpe National Transportation System Center (D.O.T.)

W Watt(s)

ºC Degrees Celsius.

% Percent π00 Reference pressure ratio

7. 34.3 General requirements:

§ 34.3(a)

(a) This part provides for the approval or acceptance by the Administrator or the Administrator of the EPA of testing and sampling methods, analytical techniques, and related equipment not identical to those specified in this part. Before either approves or accepts any such alternate, equivalent, or otherwise nonidentical procedures or equipment, the Administrator or the Administrator of the EPA shall consult with the other in determining whether or not the action requires rulemaking under sections 231 and 232 of the Clean Air Act, as amended, consistent with the responsibilities of the Administrator of the EPA and the Secretary of Transportation under sections 231 and 232 of the Clean Air Act.

Explanation This part provides for the flexibility needed to accommodate changing engine designs and possible changes and/or improvements in testing, sampling methods, analytical techniques and related equipment. This part does not provide guidelines or any systematic means of demonstrating equivalence of non-identical procedures or equipment. 40 CFR part 87, calls out, by reference, those sampling and analytical procedures specified by ICAO. ICAO does not specify particular equipment but does detail accuracy, operational and performance requirements wherever possible. For example, ICAO states the method of detection for each of the pollutants along with details of calibration and operation but does not list specific pieces of equipment.

Presumably each emissions certification test would require demonstration that each analytical technique and piece of equipment met the ICAO requirements. Similarly, it is the intent of 34.3(a) that any alternate method proposed demonstrate that it met the ICAO operational and performance requirements or their equivalent.

Each such instance would, necessarily, need to be considered on its own merit.

§ 34.3 (b) through (f):

(b) Under section 232 of the Act, the Secretary of Transportation issues regulations to ensure compliance with 40 CFR part 87. This authority has been delegated to the Administrator of the FAA (49 CFR 1.47).

(c) U.S. airplanes. This Federal Aviation Regulation (FAR) applies to civil airplanes that are powered by aircraft gas turbine engines of the classes specified herein and that have U.S. standard airworthiness certificates.

(d) Foreign airplanes. Pursuant to the definition of "aircraft" in 40 CFR 87.1(c), this FAR applies to civil airplanes that are powered by aircraft gas turbine engines of the classes specified herein and that have foreign airworthiness certificates that are equivalent to U.S. standard airworthiness certificates. This FAR applies only to those foreign civil airplanes that, if registered in the United States, would be required by applicable Federal Aviation Regulations to have a U.S. standard airworthiness certificate in order to conduct the operations intended for the airplane. Pursuant to 40 CFR 87.3(c), this FAR does not apply where it would be inconsistent with an obligation assumed by the United States to a foreign country in a treaty, convention, or agreement.