Federal Aviation Administration, DOT

Section 35.41

fixed-pitch wood propellers of conventional design.
[Amdt. 35-8, 73 FR 63348, Oct. 24, 2008]

spaschal on DSK3GDR082PROD with CFR

Section 35.39

Endurance test.

Endurance tests on the propeller system must be made on a representative
engine in accordance with paragraph
(a) or (b) of this section, as applicable,
without evidence of failure or malfunction.
(a) Fixed-pitch and ground adjustable-pitch propellers must be subjected
to one of the following tests:
(1) A 50-hour flight test in level flight
or in climb. The propeller must be operated at takeoff power and rated rotational speed during at least five hours
of this flight test, and at not less than
90 percent of the rated rotational speed
for the remainder of the 50 hours.
(2) A 50-hour ground test at takeoff
power and rated rotational speed.
(b) Variable-pitch propellers must be
subjected to one of the following tests:
(1) A 110-hour endurance test that
must include the following conditions:
(i) Five hours at takeoff power and
rotational speed and thirty 10-minute
cycles composed of:
(A) Acceleration from idle,
(B) Five minutes at takeoff power
and rotational speed,
(C) Deceleration, and
(D) Five minutes at idle.
(ii) Fifty hours at maximum continuous power and rotational speed,
(iii) Fifty hours, consisting of ten 5hour cycles composed of:
(A) Five accelerations and decelerations between idle and takeoff power
and rotational speed,
(B) Four and one half hours at approximately even incremental conditions from idle up to, but not including, maximum continuous power and
rotational speed, and
(C) Thirty minutes at idle.
(2) The operation of the propeller
throughout the engine endurance tests
prescribed in part 33 of this chapter.
(c) An analysis based on tests of propellers of similar design may be used in
place of the tests of paragraphs (a) and
(b) of this section.

Section 35.40

Functional test.

The variable-pitch propeller system
must be subjected to the applicable
functional tests of this section. The
same propeller system used in the endurance test (Section 35.39) must be used in
the functional tests and must be driven
by a representative engine on a test
stand or on an airplane. The propeller
must complete these tests without evidence of failure or malfunction. This
test may be combined with the endurance test for accumulation of cycles.
(a) Manually-controllable propellers.
Five hundred representative flight cycles must be made across the range of
pitch and rotational speed.
(b) Governing propellers. Fifteen
hundred complete cycles must be made
across the range of pitch and rotational speed.
(c) Feathering propellers. Fifty cycles of feather and unfeather operation
must be made.
(d) Reversible-pitch propellers. Two
hundred complete cycles of control
must be made from lowest normal
pitch to maximum reverse pitch. During each cycle, the propeller must run
for 30 seconds at the maximum power
and rotational speed selected by the
applicant for maximum reverse pitch.
(e) An analysis based on tests of propellers of similar design may be used in
place of the tests of this section.
[Amdt. 35-8, 73 FR 63349, Oct. 24, 2008]

Section 35.41

Overspeed and overtorque.

(a) When the applicant seeks approval of a transient maximum propeller overspeed, the applicant must
demonstrate that the propeller is capable of further operation without maintenance action at the maximum propeller overspeed condition. This may
be accomplished by:
(1) Performance of 20 runs, each of 30
seconds duration, at the maximum propeller overspeed condition; or
(2) Analysis based on test or service
experience.
(b) When the applicant seeks approval of a transient maximum propeller overtorque, the applicant must

[Amdt. 35-8, 73 FR 63348, Oct. 24, 2008]

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