IV. SUBPART C—RESERVED
No technical guidance has been developed for the following sections:
55. Section 36.301 Noise limits: Concorde
56. Section 36.301(a)
57. Section 36.301(b) V. SUBPART D—NOISE LIMITS FOR SUPERSONIC TRANSPORT CATEGORY AIRPLANES
VI. SUBPART E--[RESERVED]
No technical guidance has been developed for the following sections:
58. Section 36.501 Noise Limits
59. Section 36.501(a)
60. Section 36.501(b)
61. Section 36.501(c) VII. SUBPART F--PROPELLER-DRIVEN SMALL AIRPLANES AND PROPELLER-DRIVEN, COMMUTER
CATEGORY AIRPLANES
62. -65 [RESERVED]
VIII. SUBPART G--[RESERVED]
66. Section 36.801 Noise measurement [To be completed later]
67. Section 36.803 Noise evaluation and calculation [To be completed later]
68. Section 36.805 Noise limits [To be completed later]
69. Section 36.805(a) [To be completed later]
70. Section 36.801(b) [To be completed later]
71. Section 36.805(c)
For helicopters for which application for issuance of an original type certificate in the primary, normal, transport, or restricted category is made on or after March 6, 1986, and which the FAA finds to be the first civil version of a helicopter that was designed and constructed for, and accepted for operational use by, an Armed Force of the United States or the U.S. Coast Guard on or before March 6, 1986, it must be shown that the noise levels of the helicopter are no greater than the noise limits for a change in type design as specified in section H36.305(a)(1)(ii) of Appendix H of this part for compliance demonstrated under appendix H of this part, or as specified in section J36.305 of appendix J of this part for compliance demonstrated under appendix J of this part. Subsequent civil versions of any such helicopter must meet the Stage 2 requirements.
a. Explanation
(1) Stage 1 helicopters: The provision applicable to a helicopter based on a military design is defined. Reference is included to Appendix J but the rule does not provide the “Stage 2 + 2 dB (SEL)” or “no noisier than the parent” provision similar to the limits under Appendix H provided in section H36.305. Thus, the noise compliance discussed is essentially related to certification under the provision of Appendix H.
b. Supplemental Information
(1) Stage 1 Helicopter: If section 36.805(c) applies, then noise testing will lead to one of the following:
a) The helicopter is demonstrated to be a Stage 2 helicopter: The tradeoff provisions in section H36.305(b) may be used to demonstrate compliance with the Stage 2 noise level requirement. The certificated helicopter is not designated as a first civil version, instead the certificated helicopter is designated as a Stage 2 helicopter;
b) The helicopter is demonstrated to be a Stage 1 helicopter via the “Stage 2 + 2 EPNdB” noise limits specified in section H36.305(a)(1)(ii) and is consequently designated as the first civil version. The trade provisions in section H36.305(b) may not be used for a first civil version; or
c) The helicopter fails to demonstrate compliance with the (Stage 2 + 2) noise limits specified in section H36.305(a)(1)(ii): The helicopter will be denied a type certificate until such time that the helicopter, modified as necessary, successfully demonstrates compliance with at least the requirements for a first civil version outlined above in outcome (b). The helicopter fails to demonstrate compliance if one or more of the demonstrated Appendix H noise levels exceeds the corresponding noise level limit or that flight procedure and the helicopter does not otherwise meet the Stage 2 limits (note: a helicopter may exceed the Stage 1 limit for a given flight procedure and yet achieve Stage 2 compliance through the use of tradeoffs).
(2) Change in Type Design: If an applicant has substantiated that a proposed change in type design (as designated in section 21.93) would be less noisy or no noisier than the (parent) first civil version IX. SUBPART H--HELICOPTERS
helicopter, no additional demonstration of compliance with part 36 is required. The derivative helicopter remains a first civil version. The applicant may elect to: (1) carry forward the parent’s noise numbers to the rotorcraft flight manual of the derived version; or (2) voluntarily noise test the derivative helicopter in order to substantiate lower noise certification levels. However, if the derivative helicopter is found to be a Stage 2 helicopter as a result of the voluntary noise test, and if the applicant chooses to certify the derivative helicopter as a Stage 2 helicopter, that derivative helicopter is no longer classified as a first civil version.
(3) Subsequent Civil Version: The section 36.805(c) requirement for a subsequent civil version applies only to a helicopter previously designated as a first civil version. A subsequent civil version (unless otherwise excepted under section 21.93(b)(4) from the acoustical change requirements) is: (a) any change in type design of the first civil version that would result in one or more of the noise certification levels of the subsequent civil version that are greater than the corresponding noise certification levels of the first civil version;
or (b) any change in the first civil version that is sufficient to require a new type certificate (as provided in section
21.19). As specified in section 36.805(c), a subsequent civil version must comply with the Stage 2 noise limits.
72. Section 36.805(d) [To be completed later]
73. –75 [RESERVED]
X. SUBPARTS I--N [RESERVED]
XI. SUBPART E--RESERVED
76. Section 36.1501 Procedures, noise levels and other information
77. Section 36.1501(a)
All procedures, weights, configurations, and other information or data employed for obtaining the certified noise levels prescribed by this part, including equivalent procedures used for flight, testing, and analysis, must be developed and approved. Noise levels achieved during type certification must be included in the approved airplane (rotorcraft) flight manual.
a. Explanation
This section specifies various types of information that must be developed and approved in the course of an aircraft (airplane or rotorcraft) noise certification process.
b. Supplemental Information
Noise Certification Compliance Documentation: The following types of documentation may be required in implementation of an aircraft (airplane of rotorcraft) noise certification process.
(1) NOISE CERTIFICATION PLANS: Applicant noise certification plans should be provided to FAA in the early stages of an aircraft program and contain specific types of information including proposals for the methodology an applicant intends to use to certify a given type of aircraft. These plans, when approved, establish an aircraft’s noise certification basis under part 36. When an aircraft program involves agreements between FAA and foreign certificating authorities, these plans may specify an aircraft’s noise certification basis under both part 36 and the noise regulation used by the foreign authority (e.g., ICAO Annex 16, Volume 1; JAR 36- See references 5 and 11 of this AC). An example would be aircraft certified under FAA/JAA Concurrent and Cooperative Programs (see Note).
Noise certification plans must include the following types of information:
(i) An overview of the contents of a forthcoming noise compliance demonstration plan and noise certification report;
(ii) Description of applicable noise certification regulations and the tests, reports, data submittals and flight manual pages planned to complete an aircraft noise certification process;
(iii) Description of conformity requirements;
(iv) DERs and other cognizant personnel to be involved in the aircraft noise certification process;
(v) Milestone schedule of key events;
(vi) Miscellaneous information (e.g. acronyms, organizational codes, etc. ).
Note: The FAA/JAA Concurrent and Cooperative Programs are intended to establish (to the extent possible) commonality in compliance methods and reduce program costs. Commonality may be achieved by obtaining approval from certificating authorities to use the most stringent requirements specified by the regulations involved, or by substantiating that the requirements of the regulations involved produce equivalent noise levels (in this case an applicant may choose a method of compliance from only one regulation)
(2) NOISE COMPLIANCE DEMONSTRATION PLANS (Aircraft Flight Test): Noise compliance demonstration plans contain the specific methodology (including equivalent procedures) by which an applicant XII. SUBPART O--OPERATING LIMITATIONS AND INFORMATION
proposes to establish compliance of a specific aircraft configuration with applicable part 36 requirements. These plans must define the information, data, and procedures that an applicant proposes in order to comply with the requirements of part 36. After approval by FAA, flight tests specified in this plan are included as a part of the Type Inspection Authorization (TIA) used to fulfill requirements for TC, STC, and amended TC certification.
Noise compliance demonstration plans must include the following types of information:
(i) Introduction (Identify Applicable part 36 Requirements – Aircraft Noise Certification Basis);
(ii) Aircraft Description (Type, Model/Serial Numbers, Engines or Propellers Type, Model/Serial Numbers, Engine Ratings, Engine Nacelle Acoustic Treatments, Aircraft Gross Dimensions (including propeller and/or rotor diameter), Engine and ILS Antenna Locations, Aircraft/Engine Conformity);
(iii) Noise Certification Methodology (Test Concepts and Equivalent Procedures - See sections
1.3, 2, 3, 4, or 5 of the appended ICAO TM), Plans for Determining Engine Spooldown Characteristics and Airframe Noise, Aircraft/Engine Performance Substantiation, Estimated Reference Conditions including Airspeeds, Thrust (Power) Reduction Distances, Altitudes, Thrust (Power) Settings, Methods for determination of EPNLr Values and 90% Confidence Limits, and Flight Manual Format;
(iv) Test Description: Test Site Location and Characteristics (e.g. Topography, Ground Cover and Obstructions), Location of Noise Measurement Points, Weather Constraints, Aircraft Configuration including Flap Settings, Airbrake and Landing Gear Positions, APU Operation, Conditions of Pneumatic Bleeds and Power/Take-Offs, Test Matrix, including Weights, Target Altitudes, Airspeeds, Engine Thrust (Power), and Test Tolerances;
(v) Measurement System Components and Procedures including Calibration Procedures:
(Acoustical, Meteorological, Time/Space Position, Aircraft/Engine Performance);
(vi) Data Evaluation Procedures including Calibration and Data Processing (e.g., Approval Status of Data Processing Software and Version Level), Adjustment and Normalization Procedures: (Acoustical, Meteorological, Time/Space Position, and Airplane Engine Performance);
(vii) Aircraft Certification Schedule, including Noise Certification and TC Dates. Noise compliance plans should be submitted to FAA 60 days prior to start of testing. If new and novel equivalent procedures are proposed, or exemptions are required, then submittal of test plans earlier than 60 days prior to the start of testing may be necessary;
(viii) References;
(ix) A listing of all Equivalent Procedures utilized (e.g., Flight Path Intercept Procedure).
(3) NOISE COMPLIANCE DEMONSTRATION PLANS (Airplane Families): Noise certification of airplane families (derived versions) often require FAA approval of equivalent procedures involving measurement and evaluation of static engine noise test data as described in section 2.3 of the appended ICAO TM, in addition to the information listed in Item (2), above. These procedures include projection of static engine noise test data for development of flyover, lateral, and approach NPD plots that define differences between the airplane used for the original noise certification flight test and a derived version (See Note 1). When use of static engine noise data is proposed, test plans must also be submitted to FAA and either integrated into the basic noise compliance demonstration plan, or submitted to FAA as separate plans and referenced in the basic plan.
Static engine noise test plans must include the following information:
(i) Engine Description (Type/Model and Serial Numbers, Nacelle Acoustic Treatments, Engine Conformity Requirements);
(ii) Test Description (Test Facility, Engine Installation, Turbulence Control Screen Configuration, Weather Constraints, Acoustical and Meteorological Measurement Points, Bleed Schedules, Test Run Matrix and Sequence including Thrust (Power) Settings and Test Tolerances);
(ii) Measurement System Components and Procedures including Calibration Procedures:
(Acoustical, Meteorological, Engine Performance);
(iii) Data Evaluation Procedures including Calibration, Data Processing, Adjustment and Normalization Procedures (Acoustical, Meteorological, Engine Performance);
(v) Schedules (Static Noise Test, Noise Certification and TC dates);
(vi) References;
(vii) A listing of all Equivalent Procedures utilized.
Note 1: Applicants may also generate separate static test plans in cases where development of airplane families is anticipated but not yet formalized and there is opportunity to obtain static engine noise data (because of engine availability) for future noise certification applications.
(4) NOISE COMPLIANCE DEMONSTRATION PLANS (Analytical Methods): For certain aircraft type design changes (e.g. weight/thrust, airframe design changes and thrust (power) reduction distances or minor changes in engine components or acoustical treatments), applicants may propose using Analytical Equivalent Procedures to derive noise increments to an aircraft’s certificated noise levels (See section 2.2, 3.2 or 5.13 of the appended ICAO TM) as applicable to the type of aircraft being certificated) or to demonstrate a no acoustical change (NAC) between the original certificated aircraft and the derived version.
Noise compliance demonstration plans must include the following information:
(i) Aircraft Description (Type/Model, Engines or Propellers) Type, Model/Serial Numbers;
(ii) Description of Type Design Changes;
(iii) Noise Certification Methodology (Overall Concepts, Description/Substantiation of Analytical Equivalent Procedures or Methods of Assessment of NAC Aircraft Reference Conditions, Methods for determination of EPNLr and 90% Confidence Limit values;
(iv) Aircraft Certification Schedules;
(v) References.
(5) DER “RAW DATA” REPORTS: FAA Order 8110.37C (reference 10 of this AC) specifies that Acoustical Designated Engineering Representatives (DERs) may, within the limits of their authority (defined in their letter of appointment) and with prior FAA approval, witness noise certification tests conducted in accordance with FAA approved noise compliance demonstration plans.
In cases where tests are witnessed by DERs, the FAA may require the following information to validate that tests are being conducted in accordance with approved plans.
(i) Test Event Log (Includes Event Times and Conditions, Nominal Engine Thrusts (Powers) and Thrust (Power) Stability, Atmospheric Conditions, Airspeeds and Deviations Relative to Target Speeds, Valid and Invalid Test Points (including reasons for Invalid Points);
(ii) Test Measurement System Components (Type/Model) and Measurement/Calibration Procedures;