14 CFR § 35.37

Fatigue limits must be established by tests, or analysis based on tests, for propeller:

Hubs.

Blades.

Blade retention components.

Components which are affected by fatigue loads and which are shown under § 35.15 to have a fatigue failure mode leading to hazardous propeller effects.

The fatigue limits must take into account:

All known and reasonably foreseeable vibration and cyclic load patterns that are expected in service; and

Expected service deterioration, variations in material properties, manufacturing variations, and environmental effects.

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:

The intended airplane by complying with § 23.2400(c) or § 25.907 of this chapter, as applicable; or

A typical airplane.