FAA Aviation Mechanic Powerplant (AMP)Engine InspectionHard
A technician inspecting a fixed-pitch aluminum propeller finds a small nick approximately 1/16 inch deep on the leading edge, 8 inches from the tip. Per typical manufacturer guidance, what is the correct next step?
- AThe damage should be ignored since only cracks are inspection concerns on propellers
- BThe blade must be re-pitched to compensate for the material loss
- CThe nick may be dressed out (blended) using approved procedures if within allowable depth and location limits
- DThe propeller must be replaced immediately since any leading-edge damage is unairworthy
Show answer & explanationAnswer & explanation
Correct answer: C. The nick may be dressed out (blended) using approved procedures if within allowable depth and location limits
Minor leading-edge nicks on aluminum propeller blades can often be blended out (dressed) using files and approved procedures if the damage falls within the manufacturer's specified depth, width, and location limits, restoring an airworthy contour without requiring blade replacement.
Why the other options are wrong
- A. Nicks, cracks, corrosion pits, and erosion are all inspection concerns on propellers.
- B. Re-pitching addresses blade angle, not surface damage repair.
- D. Not all leading-edge damage requires replacement; many nicks can be repaired within limits.
Propeller Blade Damage Repair Limits
Manufacturer-specified allowable limits for dressing out minor nicks, scratches, and pitting on metal propeller blades without replacement.
- Stress risers from nicks can lead to fatigue cracking if not corrected
- Blending must maintain smooth contour and stay within depth/width limits
- Leading edge damage is a common area of inspection due to erosion and impact
Memory trick: 'Small nicks get smoothed, not scrapped'