Federal Aviation Administration, DOT § 33.96

The applicant must show by inspec- (1) That test, of the two prescribed, tion, analysis, test, or by any combina- produces the least rotor unbalance; and tion thereof as found necessary by the (2) The analysis is shown to be equiv- FAA, that structural integrity of the alent to the test. engine is maintained; or (c) In lieu of compliance with para- (Secs. 313(a), 601, and 603, Federal Aviation Act of 1958 (49 U.S.C. 1354(a), 1421, and 1423); graph (b) of this section, each engine and 49 U.S.C. 106(g) Revised, Pub. L. 97–449, for which the 30-second OEI and 2- Jan. 12, 1983) minute OEI ratings are desired, may be subjected to the endurance testing of [Amdt. 33–10, 49 FR 6854, Feb. 23, 1984] §§ 33.87 (b), (c), (d), or (e) of this part, and followed by the testing of § 33.87(f) § 33.95 Engine-propeller systems tests. without intervening disassembly and If the engine is designed to operate inspection. However, the engine must with a propeller, the following tests comply with paragraph (a) of this sec- must be made with a representative tion after completing the endurance propeller installed by either including testing of § 33.87(f). the tests in the endurance run or oth- [Doc. No. 26019, 61 FR 31329, June 19, 1996, as erwise performing them in a manner amended by Amdt. 33–25, 73 FR 48124, Aug. 18, acceptable to the Administrator: 2008] (a) Feathering operation: 25 cycles. (b) Negative torque and thrust sys- § 33.94 Blade containment and rotor tem operation: 25 cycles from rated unbalance tests. maximum continuous power. (a) Except as provided in paragraph (c) Automatic decoupler operation: 25 (b) of this section, it must be dem- cycles from rated maximum contin- onstrated by engine tests that the en- uous power (if repeated decoupling and gine is capable of containing damage recoupling in service is the intended without catching fire and without fail- function of the device). ure of its mounting attachments when (d) Reverse thrust operation: 175 cy- operated for at least 15 seconds, unless cles from the flight-idle position to full the resulting engine damage induces a reverse and 25 cycles at rated max- self shutdown, after each of the fol- imum continuous power from full for- lowing events: ward to full reverse thrust. At the end (1) Failure of the most critical com- of each cycle the propeller must be op- pressor or fan blade while operating at erated in reverse pitch for a period of maximum permissible r.p.m. The blade failure must occur at the outermost re- 30 seconds at the maximum rotational tention groove or, for integrally-bladed speed and power specified by the appli- rotor discs, at least 80 percent of the cant for reverse pitch operation. blade must fail. [Doc. No. 3025, 29 FR 7453, June 10, 1964, as (2) Failure of the most critical tur- amended by Amdt. 33–3, 32 FR 3737, Mar. 4, bine blade while operating at max- 1967] imum permissible r.p.m. The blade fail- ure must occur at the outermost reten- § 33.96 Engine tests in auxiliary power tion groove or, for integrally-bladed unit (APU) mode. rotor discs, at least 80 percent of the If the engine is designed with a pro- blade must fail. The most critical tur- peller brake which will allow the pro- bine blade must be determined by con- peller to be brought to a stop while the sidering turbine blade weight and the gas generator portion of the engine re- strength of the adjacent turbine case mains in operation, and remain stopped at case temperatures and pressures as- during operation of the engine as an sociated with operation at maximum auxiliary power unit (‘‘APU mode’’), in permissible r.p.m. addition to the requirements of § 33.87, (b) Analysis based on rig testing, the applicant must conduct the fol- component testing, or service experi- lowing tests: ence may be substitute for one of the engine tests prescribed in paragraphs (a) Ground locking: A total of 45 (a)(1) and (a)(2) of this section if— hours with the propeller brake engaged

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in a manner which clearly dem- full reverse thrust for a period of one onstrates its ability to function with- minute, except that, in the case of a re- out adverse effects on the complete en- verser intended for use only as a brak- gine while the engine is operating in ing means on the ground, the reverser the APU mode under the maximum need only be operated at full reverse conditions of engine speed, torque, thrust for 30 seconds. temperature, air bleed, and power ex- traction as specified by the applicant. [Doc. No. 3025, 29 FR 7453, June 10, 1964, as amended by Amdt. 33–3, 32 FR 3737, Mar. 4, (b) Dynamic braking: A total of 400 1967] application-release cycles of brake en- gagements must be made in a manner § 33.99 General conduct of block tests. which clearly demonstrates its ability (a) Each applicant may, in making a to function without adverse effects on block test, use separate engines of the complete engine under the max- identical design and construction in imum conditions of engine accelera- the vibration, calibration, endurance, tion/deceleration rate, speed, torque, and operation tests, except that, if a and temperature as specified by the ap- separate engine is used for the endur- plicant. The propeller must be stopped ance test it must be subjected to a cali- prior to brake release. (c) One hundred engine starts and bration check before starting the en- stops with the propeller brake engaged. durance test. (d) The tests required by paragraphs (b) Each applicant may service and (a), (b), and (c) of this section must be make minor repairs to the engine dur- performed on the same engine, but this ing the block tests in accordance with engine need not be the same engine the service and maintenance instruc- used for the tests required by § 33.87. tions submitted in compliance with (e) The tests required by paragraphs § 33.4. If the frequency of the service is (a), (b), and (c) of this section must be excessive, or the number of stops due followed by engine disassembly to the to engine malfunction is excessive, or a extent necessary to show compliance major repair, or replacement of a part with the requirements of § 33.93(a) and is found necessary during the block § 33.93(b). tests or as the result of findings from the teardown inspection, the engine or [Amdt. 33–11, 51 FR 10346, Mar. 25, 1986] its parts must be subjected to any addi- tional tests the Administrator finds § 33.97 Thrust reversers. necessary. (a) If the engine incorporates a re- (c) Each applicant must furnish all verser, the endurance calibration, oper- testing facilities, including equipment ation, and vibration tests prescribed in and competent personnel, to conduct this subpart must be run with the re- the block tests. verser installed. In complying with this section, the power control lever must [Doc. No. 3025, 29 FR 7453, June 10, 1964, as be moved from one extreme position to amended by Amdt. 33–6, 39 FR 35470, Oct. 1, the other in not more than one second 1974; Amdt. 33–9, 45 FR 60181, Sept. 11, 1980] except, if regimes of control operations are incorporated necessitating sched- Subpart G—Special Requirements: uling of the power-control lever motion Turbine Aircraft Engines in going from one extreme position to the other, a longer period of time is ac- SOURCE: Docket No. FAA–2002–6717, 72 FR ceptable but not more than three sec- 1877, Jan. 16, 2007, unless otherwise noted. onds. In addition, the test prescribed in paragraph (b) of this section must be § 33.201 Design and test requirements made. This test may be scheduled as for Early ETOPS eligibility. part of the endurance run. An applicant seeking type design ap- (b) 175 reversals must be made from proval for an engine to be installed on flight-idle forward thrust to maximum a two-engine airplane approved for reverse thrust and 25 reversals must be ETOPS without the service experience made from rated takeoff thrust to max- specified in part 25, appendix K, K25.2.1 imum reverse thrust. After each rever- of this chapter, must comply with the sal the reverser must be operated at following:

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