Federal Aviation Administration, DOT

Section 33.95

that were established and recorded at
the beginning of the test; and
(2) Each engine part must conform to
the type design and be eligible for incorporation into an engine for continued operation, in accordance with information submitted in compliance
with Section 33.4.
(b) After completing the endurance
testing of Section 33.87(f), each engine must be
completely disassembled, and
(1) Each component having an adjustment setting and a functioning characteristic that can be established independent of installation on the engine
must retain each setting and functioning characteristic within the limits
that were established and recorded at
the beginning of the test; and
(2) Each engine may exhibit deterioration in excess of that permitted in
paragraph (a)(2) of this section, including some engine parts or components
that may be unsuitable for further use.
The applicant must show by inspection, analysis, test, or by any combination thereof as found necessary by the
FAA, that structural integrity of the
engine is maintained; or
(c) In lieu of compliance with paragraph (b) of this section, each engine
for which the 30-second OEI and 2minute OEI ratings are desired, may be
subjected to the endurance testing of
SectionSection 33.87 (b), (c), (d), or (e) of this part,
and followed by the testing of Section 33.87(f)
without intervening disassembly and
inspection. However, the engine must
comply with paragraph (a) of this section after completing the endurance
testing of Section 33.87(f).

spaschal on DSK3GDR082PROD with CFR

[Doc. No. 26019, 61 FR 31329, June 19, 1996, as
amended by Amdt. 33-25, 73 FR 48124, Aug. 18,
2008]

Section 33.94 Blade containment and rotor
unbalance tests.
(a) Except as provided in paragraph
(b) of this section, it must be demonstrated by engine tests that the engine is capable of containing damage
without catching fire and without failure of its mounting attachments when
operated for at least 15 seconds, unless
the resulting engine damage induces a
self shutdown, after each of the following events:
(1) Failure of the most critical compressor or fan blade while operating at

maximum permissible r.p.m. The blade
failure must occur at the outermost retention groove or, for integrally-bladed
rotor discs, at least 80 percent of the
blade must fail.
(2) Failure of the most critical turbine blade while operating at maximum permissible r.p.m. The blade failure must occur at the outermost retention groove or, for integrally-bladed
rotor discs, at least 80 percent of the
blade must fail. The most critical turbine blade must be determined by considering turbine blade weight and the
strength of the adjacent turbine case
at case temperatures and pressures associated with operation at maximum
permissible r.p.m.
(b) Analysis based on rig testing,
component testing, or service experience may be substitute for one of the
engine tests prescribed in paragraphs
(a)(1) and (a)(2) of this section if - 
(1) That test, of the two prescribed,
produces the least rotor unbalance; and
(2) The analysis is shown to be equivalent to the test.
(Secs. 313(a), 601, and 603, Federal Aviation
Act of 1958 (49 U.S.C. 1354(a), 1421, and 1423);
and 49 U.S.C. 106(g) Revised, Pub. L. 97-449,
Jan. 12, 1983)
[Amdt. 33-10, 49 FR 6854, Feb. 23, 1984]

Section 33.95

Engine-propeller systems tests.

If the engine is designed to operate
with a propeller, the following tests
must be made with a representative
propeller installed by either including
the tests in the endurance run or otherwise performing them in a manner
acceptable to the Administrator:
(a) Feathering operation: 25 cycles.
(b) Negative torque and thrust system operation: 25 cycles from rated
maximum continuous power.
(c) Automatic decoupler operation: 25
cycles from rated maximum continuous power (if repeated decoupling and
recoupling in service is the intended
function of the device).
(d) Reverse thrust operation: 175 cycles from the flight-idle position to full
reverse and 25 cycles at rated maximum continuous power from full forward to full reverse thrust. At the end
of each cycle the propeller must be operated in reverse pitch for a period of
30 seconds at the maximum rotational

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