Section 33.96

14 CFR Ch. I (1-1-19 Edition)

speed and power specified by the applicant for reverse pitch operation.
[Doc. No. 3025, 29 FR 7453, June 10, 1964, as
amended by Amdt. 33-3, 32 FR 3737, Mar. 4,
1967]

Section 33.96 Engine tests in auxiliary power
unit (APU) mode.
If the engine is designed with a propeller brake which will allow the propeller to be brought to a stop while the
gas generator portion of the engine remains in operation, and remain stopped
during operation of the engine as an
auxiliary power unit ( - APU mode - ), in
addition to the requirements of Section 33.87,
the applicant must conduct the following tests:
(a) Ground locking: A total of 45
hours with the propeller brake engaged
in a manner which clearly demonstrates its ability to function without adverse effects on the complete engine while the engine is operating in
the APU mode under the maximum
conditions of engine speed, torque,
temperature, air bleed, and power extraction as specified by the applicant.
(b) Dynamic braking: A total of 400
application-release cycles of brake engagements must be made in a manner
which clearly demonstrates its ability
to function without adverse effects on
the complete engine under the maximum conditions of engine acceleration/deceleration rate, speed, torque,
and temperature as specified by the applicant. The propeller must be stopped
prior to brake release.
(c) One hundred engine starts and
stops with the propeller brake engaged.
(d) The tests required by paragraphs
(a), (b), and (c) of this section must be
performed on the same engine, but this
engine need not be the same engine
used for the tests required by Section 33.87.
(e) The tests required by paragraphs
(a), (b), and (c) of this section must be
followed by engine disassembly to the
extent necessary to show compliance
with the requirements of Section 33.93(a) and
Section 33.93(b).

spaschal on DSK3GDR082PROD with CFR

[Amdt. 33-11, 51 FR 10346, Mar. 25, 1986]

Section 33.97

Thrust reversers.

(a) If the engine incorporates a reverser, the endurance calibration, operation, and vibration tests prescribed in

this subpart must be run with the reverser installed. In complying with this
section, the power control lever must
be moved from one extreme position to
the other in not more than one second
except, if regimes of control operations
are incorporated necessitating scheduling of the power-control lever motion
in going from one extreme position to
the other, a longer period of time is acceptable but not more than three seconds. In addition, the test prescribed in
paragraph (b) of this section must be
made. This test may be scheduled as
part of the endurance run.
(b) 175 reversals must be made from
flight-idle forward thrust to maximum
reverse thrust and 25 reversals must be
made from rated takeoff thrust to maximum reverse thrust. After each reversal the reverser must be operated at
full reverse thrust for a period of one
minute, except that, in the case of a reverser intended for use only as a braking means on the ground, the reverser
need only be operated at full reverse
thrust for 30 seconds.
[Doc. No. 3025, 29 FR 7453, June 10, 1964, as
amended by Amdt. 33-3, 32 FR 3737, Mar. 4,
1967]

Section 33.99

General conduct of block tests.

(a) Each applicant may, in making a
block test, use separate engines of
identical design and construction in
the vibration, calibration, endurance,
and operation tests, except that, if a
separate engine is used for the endurance test it must be subjected to a calibration check before starting the endurance test.
(b) Each applicant may service and
make minor repairs to the engine during the block tests in accordance with
the service and maintenance instructions submitted in compliance with
Section 33.4. If the frequency of the service is
excessive, or the number of stops due
to engine malfunction is excessive, or a
major repair, or replacement of a part
is found necessary during the block
tests or as the result of findings from
the teardown inspection, the engine or
its parts must be subjected to any additional tests the Administrator finds
necessary.
(c) Each applicant must furnish all
testing facilities, including equipment

736

VerDate Sep<11>2014

12:50 Apr 30, 2019

Jkt 247046

PO 00000

Frm 00746

Fmt 8010

Sfmt 8010

Y:\SGML\247046.XXX

247046