Aircraft Propeller Systems Flashcards

When an oil-counterweight propeller loses oil pressure, the blades will move toward:

Answer: High pitch (coarse)

In a counterweight-type propeller, counterweights move blades toward high pitch (coarse); oil pressure moves them toward low pitch, so loss of oil causes blades to go high pitch.

Which maintenance action requires weighing each propeller blade individually?

Answer: Replacing a blade in a composite multi-piece hub

When replacing a blade in a removable-blade composite hub, each blade must be weighed to select a matched-weight replacement and restore propeller balance.

A propeller tachometer reads 300 RPM lower than the engine tachometer on a direct-drive engine. The technician should:

Answer: Suspect a slipping propeller hub or flange

On a direct-drive engine, the propeller must turn at the same RPM as the crankshaft; a large discrepancy suggests propeller slippage on the shaft.

Corrosion found on the bore of an aluminum propeller hub should be:

Answer: Sent to a certificated propeller repair station for evaluation

Hub bore corrosion is a critical area; the propeller must be sent to a certificated repair station because improper repairs can cause hub failure.

What happens to blade pitch in a constant-speed propeller when the aircraft descends and engine RPM tends to increase above the governor set point?

Answer: Pitch increases to absorb the additional power and maintain RPM

When RPM rises above the set point, governor flyweights open a port directing oil to increase blade pitch, adding load to bring RPM back to the selected value.

The primary advantage of a composite propeller blade over an aluminum blade is:

Answer: Improved fatigue life and lighter weight

Composite blades offer superior fatigue resistance and are lighter than equivalent aluminum blades, improving overall aircraft performance.

According to FAA regulations, a major propeller repair must be performed by:

Answer: A certificated propeller repair station or the propeller manufacturer

14 CFR Part 65 and Part 145 require that major propeller repairs be accomplished by a certificated propeller repair station or the original manufacturer.