Section 35.35

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

prior to implementation and may require additional testing. Any unscheduled repair or action on the test article
must be recorded and reported.
[Amdt. 35-8, 73 FR 63348, Oct. 24, 2008]

Section 35.35 Centrifugal load tests.
The applicant must demonstrate that
a propeller complies with paragraphs
(a), (b) and (c) of this section without
evidence of failure, malfunction, or
permanent deformation that would result in a major or hazardous propeller
effect. When the propeller could be sensitive to environmental degradation in
service, this must be considered. This
section does not apply to fixed-pitch
wood or fixed-pitch metal propellers of
conventional design.
(a) The hub, blade retention system,
and counterweights must be tested for
a period of one hour to a load equivalent to twice the maximum centrifugal
load to which the propeller would be
subjected during operation at the maximum rated rotational speed.
(b) Blade features associated with
transitions to the retention system (for
example, a composite blade bonded to a
metallic retention) must be tested either during the test of paragraph (a) of
this section or in a separate component
test for a period of one hour to a load
equivalent to twice the maximum centrifugal load to which the propeller
would be subjected during operation at
the maximum rated rotational speed.
(c) Components used with or attached
to the propeller (for example, spinners,
de-icing equipment, and blade erosion
shields) must be subjected to a load
equivalent to 159 percent of the maximum centrifugal load to which the
component would be subjected during
operation at the maximum rated rotational speed. This must be performed
by either:
(1) Testing at the required load for a
period of 30 minutes; or
(2) Analysis based on test.

spaschal on DSK3GDR082PROD with CFR

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

Section 35.36 Bird impact.
The applicant must demonstrate, by
tests or analysis based on tests or experience on similar designs, that the propeller can withstand the impact of a 4pound bird at the critical location(s)

and critical flight condition(s) of a typical installation without causing a
major or hazardous propeller effect.
This section does not apply to fixedpitch wood propellers of conventional
design.
[Amdt. 35-8, 73 FR 63348, Oct. 24, 2008]

Section 35.37

Fatigue limits and evaluation.

This section does not apply to fixedpitch wood propellers of conventional
design.
(a) Fatigue limits must be established by tests, or analysis based on
tests, for propeller:
(1) Hubs.
(2) Blades.
(3) Blade retention components.
(4) Components which are affected by
fatigue loads and which are shown
under Section 35.15 to have a fatigue failure
mode leading to hazardous propeller effects.
(b) The fatigue limits must take into
account:
(1) All known and reasonably foreseeable vibration and cyclic load patterns
that are expected in service; and
(2) Expected service deterioration,
variations in material properties, manufacturing variations, and environmental effects.
(c) A fatigue evaluation of the propeller must be conducted to show that
hazardous propeller effects due to fatigue will be avoided throughout the
intended operational life of the propeller on either:
(1) The intended airplane by complying with Section 23.2400(c) or Section 25.907 of this
chapter, as applicable; or
(2) A typical airplane.
[Amdt. 35-8, 73 FR 63348, Oct. 24, 2008, as
amended by Doc. FAA-2015-1621, Amdt. 35-10,
81 FR 96700, Dec. 30, 2016]

Section 35.38

Lightning strike.

The applicant must demonstrate, by
tests, analysis based on tests, or experience on similar designs, that the propeller can withstand a lightning strike
without causing a major or hazardous
propeller effect. The limit to which the
propeller has been qualified must be
documented in the appropriate manuals. This section does not apply to

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