Home › Part 107 Practice Tests › Maintenance & Preflight Inspection Questions › Question 3
When you rotate a motor by hand during preflight, it feels gritty and makes a scraping sound unlike the other motors. What should you do?
- A.Fly briefly, because the sound usually clears once the motor warms up
- B.Do not fly until the motor is inspected and the cause is corrected
- C.Ignore it if the aircraft passed its last flight without a problem
Correct answer
B. Do not fly until the motor is inspected and the cause is corrected
Why
Abnormal resistance, looseness, or noise when a motor turns can indicate bearing damage or debris. Flying in that condition risks an in-flight motor failure, so the aircraft should remain grounded.
Source: FAA-G-8082-22 Ch. 12 · ACS knowledge area: Maintenance and Preflight Inspection Procedures · From the Maintenance & Preflight Inspection practice bank (MNT-003).