FAA Aviation Mechanic Powerplant (AMP)PropellersMedium
An aircraft strikes a runway light with a rotating propeller during taxi at low power. According to standard maintenance practice, what must be done regardless of visible propeller damage?
- AOnly the propeller needs inspection since the engine was not directly struck
- BThe aircraft may be returned to service after a simple visual inspection of the spinner only
- CBoth the propeller and the engine must be inspected per manufacturer instructions for sudden stoppage or propeller strike
- DNo action is required if the propeller shows no visible cracks or bends
Show answer & explanationAnswer & explanation
Correct answer: C. Both the propeller and the engine must be inspected per manufacturer instructions for sudden stoppage or propeller strike
A propeller strike, even without visible damage, can transmit shock loads through the crankshaft, gearbox, and accessory drives. Manufacturer instructions typically require inspection or teardown of both the propeller and engine (including crankshaft flange runout checks and possibly engine teardown) following a propeller strike event.
Why the other options are wrong
- A. Engine internal components can be damaged even if only the propeller made contact.
- B. A spinner-only visual check is inadequate for assessing internal shock load damage.
- D. Internal damage may not be visible externally, so inspection is still required.
Propeller Strike Inspection
After any propeller strike or sudden stoppage, both the propeller and engine must be inspected per the manufacturer's instructions, since internal shock damage may not be visible.
- Includes crankshaft flange runout checks
- May require engine teardown depending on severity/manufacturer criteria
- Applies even if there is no visible propeller damage
Memory trick: A strike shakes the WHOLE engine, not just the prop tip