FAA Aviation Mechanic Powerplant (AMP)PropellersHard
An inspector is checking a propeller for track and balance. What is the primary difference between these two checks?
- ATrack measures the path each blade tip follows in one plane; balance measures the distribution of weight around the propeller
- BTrack and balance are two names for the same inspection procedure
- CTrack is checked statically; balance is checked only dynamically during engine run-up
- DTrack measures blade weight distribution; balance measures blade tip path alignment
Show answer & explanationAnswer & explanation
Correct answer: A. Track measures the path each blade tip follows in one plane; balance measures the distribution of weight around the propeller
Propeller track checks that all blade tips travel in the same rotational plane (measured with a fixed reference and rotating the prop by hand). Balance ensures that the weight is evenly distributed so the propeller does not cause vibration; balance can be checked statically or dynamically, but track and balance are distinct measurements.
Why the other options are wrong
- B. Track and balance test different things and are not the same procedure.
- C. Both track and balance can be checked using various methods; this statement oversimplifies incorrectly.
- D. This reverses the correct definitions of track and balance.
Propeller Track and Balance
Track verifies all blade tips travel in the same plane; balance verifies even weight distribution to prevent vibration.
- Track checked with a fixed pointer/board and rotating prop by hand
- Balance can be static (bench) or dynamic (running engine)
- Out-of-track or out-of-balance both cause vibration but from different causes
Memory trick: Track = path of the tips, Balance = weight of the blades