Airframe Mechanic Certification Airframe Inspection Procedures 2 — Questions and Answers
Question 1: Which document defines the minimum inspection requirements for a 100-hour inspection on a certificated aircraft?
- 14 CFR Part 43, Appendix D (Correct answer)
- 14 CFR Part 91.409
- AC 43.13-1B
- The aircraft's weight and balance report
Correct answer: 14 CFR Part 43, Appendix D
14 CFR Part 43, Appendix D lists the scope and detail of items to be included in annual and 100-hour inspections.
Question 2: When inspecting a fuselage skin for corrosion, which type is most difficult to detect because it forms beneath the surface?
- Uniform surface corrosion
- Intergranular corrosion (Correct answer)
- Galvanic corrosion
- Filiform corrosion
Correct answer: Intergranular corrosion
Intergranular corrosion attacks grain boundaries beneath the surface and may not be visible until the metal blisters or delaminate.
Question 3: During a control surface inspection, you notice the hinge pin has 0.010 inch of lateral play. The manufacturer's limit is 0.005 inch. What is the correct action?
- Lubricate the hinge and re-check
- Document and monitor at next inspection
- Replace the hinge assembly before returning to service (Correct answer)
- Apply safety wire to restrict movement
Correct answer: Replace the hinge assembly before returning to service
Exceeding manufacturer limits requires replacement before return to service; documenting and monitoring is not acceptable when a limit is exceeded.
Question 4: A mechanic performs a 100-hour inspection and discovers a cracked engine mount. Who must sign the return-to-service entry after the repair?
- Any certificated A&P mechanic (Correct answer)
- Only an IA (Inspection Authorization) holder
- The aircraft owner
- A certificated repair station only
Correct answer: Any certificated A&P mechanic
An A&P mechanic may approve a repair for return to service; an IA is only required to approve the annual inspection itself.
Question 5: Which NDT method is best suited for detecting subsurface cracks in aluminum airframe structure without removing paint?
- Dye penetrant inspection
- Magnetic particle inspection
- Eddy current inspection (Correct answer)
- Visual inspection with magnification
Correct answer: Eddy current inspection
Eddy current inspection can detect subsurface flaws in non-ferrous metals through paint and coatings without removal.
Question 6: When is a logbook entry for an inspection considered complete per 14 CFR Part 43.11?
- When the mechanic verbally notifies the owner
- When the date, aircraft total time, and mechanic signature/certificate number are recorded (Correct answer)
- When the FAA Form 8130-3 is filed
- When a squawk sheet is attached to the airframe log
Correct answer: When the date, aircraft total time, and mechanic signature/certificate number are recorded
Part 43.11 requires the entry to include the date, aircraft total time in service, and the signature and certificate number of the approving mechanic.
Question 7: During an airframe inspection, a mechanic finds a dent in the fuselage skin that is 3 inches in diameter and 1/4 inch deep with no cracks. According to AC 43.13-1B, what is the primary concern?
- The dent changes aerodynamic drag
- The dent may indicate internal structural damage (Correct answer)
- The paint must be stripped for further evaluation only
- A dent of this size is always within limits
Correct answer: The dent may indicate internal structural damage
Dents can indicate underlying structural damage such as cracked frames or stringers that require inspection of internal structure.
