(a) Each variable-pitch propeller must be subjected to the applicable functional tests of this section. The same propeller used in the endurance test must be used in the functional tests and must be driven by an engine on a test stand or on an aircraft.

(b) Manually controllable propellers. 500 complete cycles of control must be made throughout the pitch and rotational speed ranges.

(c) Automatically controllable propellers. 1,500 complete cycles of control must be made throughout the pitch and rotational speed ranges.

(d) Feathering propellers. 50 cycles of feathering operation must be made.

(e) Reversible-pitch propellers. Two hundred complete cycles of control must be made from lowest normal pitch to maximum reverse pitch, and, while in maximum reverse pitch, during each cycle, the propeller must be run for 30 seconds at the maximum power and rotational speed selected by the applicant for maximum reverse pitch.

[Doc. No. 2095, 29 FR 7458, June 10, 1964, as amended by Amdt. 35-3, 41 FR 55475, Dec. 20, 1976]