Code of Federal Regulations - Title 14

901

Federal Aviation Administration, DOT

§ 35.19

the propeller installation and oper-
ation instructions required under § 35.3.

(e) If the safety analysis depends on

one or more of the following items,
those items must be identified in the
analysis and appropriately substan-
tiated.

(1) Maintenance actions being carried

out at stated intervals. This includes
verifying that items that could fail in
a latent manner are functioning prop-
erly. When necessary to prevent haz-
ardous propeller effects, these mainte-
nance actions and intervals must be
published in the instructions for con-
tinued airworthiness required under
§ 35.4. Additionally, if errors in mainte-
nance of the propeller system could
lead to hazardous propeller effects, the
appropriate maintenance procedures
must be included in the relevant pro-
peller manuals.

(2) Verification of the satisfactory

functioning of safety or other devices
at pre-flight or other stated periods.
The details of this satisfactory func-
tioning must be published in the appro-
priate manual.

(3) The provision of specific instru-

mentation not otherwise required.
Such instrumentation must be pub-
lished in the appropriate documenta-
tion.

(4) A fatigue assessment.
(f) If applicable, the safety analysis

must include, but not be limited to, as-
sessment of indicating equipment,
manual and automatic controls, gov-
ernors and propeller control systems,
synchrophasers, synchronizers, and
propeller thrust reversal systems.

(g) Unless otherwise approved by the

Administrator and stated in the safety
analysis, the following failure defini-
tions apply to compliance with this
part.

(1) The following are regarded as haz-

ardous propeller effects:

(i) The development of excessive

drag.

(ii) A significant thrust in the oppo-

site direction to that commanded by
the pilot.

(iii) The release of the propeller or

any major portion of the propeller.

(iv) A failure that results in excessive

unbalance.

(2) The following are regarded as

major propeller effects for variable
pitch propellers:

(i) An inability to feather the pro-

peller for feathering propellers.

(ii) An inability to change propeller

pitch when commanded.

(iii) A significant uncommanded

change in pitch.

(iv) A significant uncontrollable

torque or speed fluctuation.

[Amdt. 35–8, 73 FR 63346, Oct. 24, 2008, as
amended by Amdt. 35–9, 78 FR 4041, Jan. 18,
2013; Amdt. 35–9A, 78 FR 45052, July 26, 2013]

§ 35.16

Propeller critical parts.

The integrity of each propeller crit-

ical part identified by the safety anal-
ysis required by § 35.15 must be estab-
lished by:

(a) A defined engineering process for

ensuring the integrity of the propeller
critical part throughout its service life,

(b) A defined manufacturing process

that identifies the requirements to
consistently produce the propeller crit-
ical part as required by the engineering
process, and

process that identifies the continued
airworthiness requirements of the pro-
peller critical part as required by the
engineering process.

[Amdt. 35–9, 78 FR 4042, Jan. 18, 2013]

§ 35.17

Materials and manufacturing

methods.

(a) The suitability and durability of

materials used in the propeller must:

(1) Be established on the basis of ex-

perience, tests, or both.

(2) Account for environmental condi-

tions expected in service.

(b) All materials and manufacturing

methods must conform to specifica-
tions acceptable to the Administrator.

materials must be suitably related to
the most adverse properties stated in
the material specification for applica-
ble conditions expected in service.

[Amdt. 35–8, 73 FR 63347, Oct. 24, 2008]

§ 35.19

Durability.

Each part of the propeller must be

designed and constructed to minimize

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