|33.70-1||ANE-111||Guidance Material for Aircraft Engine Life-Limited Parts Requirements||07-31-2009|
Engine Fire Protection
This advisory circular (AC) provides definitions, guidance, and acceptable methods, but not the only methods, that may be used to demonstrate compliance with the engine fire protection requirements of Title 14 Code of Federal Regulations (14 CFR 33.17). The guidance provided in this AC supersedes information contained in AC 33-2B titled "Aircraft Engine Type Certification Handbook" (Chapter 3, Section 22, titled "Section 33.17, Fire Prevention").
Bird Ingestion Certification Standards
This advisory circular (AC) provides guidance and acceptable methods, but not the only methods, that may be used to demonstrate compliance with the bird ingestion requirements of Title 14 of the Code of Federal Regulations (14 CFR) § 33.76. Although this AC does refer to regulatory requirements that are mandatory, this AC is not, in itself, mandatory. This AC neither changes any regulatory requirements, nor authorizes changes in, or deviations from, the regulatory requirements.
Guidance for Parts Manufacturer Approval of Turbine Engine and Auxiliary Power Unit Parts under Test and Computation
This advisory circular (AC) provides guidance for developing substantiation data to support the design approval of critical and complex turbine engine and auxiliary power unit (APU) parts produced under parts manufacturer approval (PMA). This guidance is for the comparative test and analysis method used to show compliance to the airworthiness requirements under test and computation, per § 21.303 of Title 14 of the Code of Federal Regulations(14 CFR). This method supports showing the engine or APU still complies with 14 CFR part 33 and Technical Standard Order (TSO) C77.
b. Additionally, this AC provides information on developing a continued operational safety (COS) plan and part numbering for turbine engine parts.
Damage Tolerance of Hole Features in High-Energy Turbine
This advisory circular (AC) provides definitions, guidance, and acceptable methods, but not the only methods, that may be used to demonstrate compliance with requirements in § 33.70 of Title 14 of the Code of Federal Regulations related to the integrity of engine life-limited parts. Section 33.70 contains requirements applicable to the design and life management of propulsion system life-limited parts, including high-energy rotating parts.
This AC presents a damage tolerance approach which can be used to address manufacturing and operationally-induced anomalies in turbine engine rotating part hole features. This approach can be readily integrated with the existing “safe-life” process for high-energy rotors to produce an enhanced life management process. This approach does not replace existing safe-life methodology but supplements it. In the context of damage tolerance, this AC is not intended to allow operation beyond the component manual life limit set using the existing safe life approach which limits the useful rotor life to the minimum number of flight cycles required to initiate a crack. Rotor failure modes for which full containment of high-energy debris can be demonstrated are excluded from the procedures outlined in this AC and need not be accounted for in the overall risk assessment.
Comparative Method to Show Equivalent Vibratory Stresses and High Cycle Fatigue Capability for Parts Manufacturer Approval of Turbine Engine and Auxiliary Power Unit Parts
This advisory circular (AC) describes a comparative test and analysis method that may be used for turbine engine or auxiliary power unit (APU) blades or vanes when produced under parts manufacturer approval (PMA). PMA applicants may use this comparative modal and high-cycle fatigue (HCF) method to show the vibratory stresses and HCF capability of their proposed blades or vanes are equivalent to those of the type design parts. This method supports showing that the engine or APU still complies with part 33 of Title 14 of the Code of Federal Regulations (14 CFR part 33) or Technical Standard Order (TSO) C77.
Developing Data for Major Repairs of Turbine Engine Parts
a. This advisory circular (AC) provides information and guidance on developing the technical data needed for major repairs of critical and complex turbine engine parts. This guidance will help persons developing major repair data meet the requirements of Title 14 of the Code of Federal Regulations (14 CFR) part 43 to restore the engine to at least equal to its original or properly altered condition. This does not mean that a repaired part must be returned to a factory-new condition. However, the engine on which the repaired part is installed must remain airworthy and in compliance with the applicable regulations. For repairs of turbine engines and parts, the applicable requirements are Airworthiness Standards: Aircraft Engines (14 CFR part 33) and Fuel Venting and Exhaust Emissions Requirements for Turbine Engine Powered Airplanes (14 CFR part 34).
b. Additionally, this AC provides guidance to assist persons developing major repairs with developing a continued operational safety plan. It also helps them evaluate engine parts recovered from accidents and incidents prior to making a repair.
General Type Certification Guidelines for Turbine Engines
This advisory circular (AC) provides general guidance concerning type certification projects for aircraft turbine engines. This AC applies to certain sections of Title 14 of the Code of Federal Regulations (14 CFR) parts 21, 33, and 45, and describes or references methods of compliance that may be acceptable for engine type certification work. This guidance is general in nature, and where necessary, further reference is made to other documents, which may be the primary source for information on a particular subject.
Statistical Analysis Considerations for Comparative Test and Analysis Based Compliance Findings for Turbine Engine and Auxiliary Power Unit Replacement, Redesign and Repaired Parts
a. This advisory circular (AC) describes acceptable statistical methods, but not the only methods, to help develop substantiating data for comparative test and analysis compliance findings. The findings support the Federal Aviation Administration (FAA) approval of turbine engine and auxiliary power unit (APU) replacement, redesign and repaired parts produced under:
(1) Parts manufacturer approval (PMA),
(2) Type Certificate (TC),
(3) Supplemental Type Certificate (STC), or
(4) Repair or alteration.
b. The AC describes statistical principles that can be used to help determine adequate sample sizes for a comparative showing of equivalency of parts from different design or manufacturing processes. The guidance in this AC is acceptable for determining sample sizes and/or populations of specimens. The resulting data may be used to support a showing of compliance to the airworthiness requirements of Title 14 of the Code of Federal Regulations (14 CFR) 21.303, 14 CFR part 33, 14 CFR part 43 and Technical Standard Order (TSO) C77.
Oxidation, Hot Corrosion, Thermal Fatigue, and Erosion Characteristics Testing to Support 14 CFR, Part 33, § 33.15, Compliancefor Turbine Engines
This advisory circular (AC) describes an acceptable method, but not the only method, to support certain comparative assessment compliance findings to Title 14 of the Code of Federal Regulations (14 CFR) part 33, § 33.15, Materials, for turbine engine projects. Comparative assessment of certain data is often necessary to show the required functional and durability equivalencies between engine combustor and turbine section parts from different design or manufacturing processes, e.g., parts manufacturer approvals (PMA) versus type design parts. These equivalencies relate to oxidation, hot corrosion, and thermal fatigue and erosion characteristics in the engine environment. This data is necessary to support overall FAA design approval of turbine engine and auxiliary power unit (APU) parts approved under PMA, type certificate (TC) design change, supplemental type certificate (STC), or repair or alteration authority.
Engine Overtorque Test, Calibration Test, Endurance Test, and Teardown Inspection for Turbine Engine Certification (§§ 33.84, 33.85, 33.87, 33.93)
a. This advisory circular (AC) provides a method of compliance for the test requirements of Title 14, of the Code of Federal Regulations (14 CFR) 33.84 (engine overtorque test) when the applicant chooses to run that test as part of the endurance test of § 33.87. It also provides information and guidance on the test requirements of § 33.85 (calibration test), § 33.87 (endurance test), and § 33.93 (teardown inspection).
b. This AC applies to part 33 type certification endurance testing of all classes of turbine engines.