Airframe Mechanic Certification Aircraft Systems & Components 5 — Questions and Answers
Question 1: What condition does a cracked or chafed pitot tube indicate regarding airworthiness?
- The aircraft is airworthy if the crack is less than 1 inch
- The pitot tube must be replaced before flight (Correct answer)
- The crack can be repaired with sealant if minor
- Only the static system needs inspection
Correct answer: The pitot tube must be replaced before flight
A cracked or chafed pitot tube compromises airspeed indication and is an unairworthy condition requiring replacement before flight.
Question 2: In aircraft fabric covering, what is the purpose of the dope applied over the fabric?
- Bond the fabric to the structure
- Tighten and weatherproof the fabric and provide a paintable surface (Correct answer)
- Provide fire resistance
- Improve aerodynamic smoothness only
Correct answer: Tighten and weatherproof the fabric and provide a paintable surface
Dope tautens the fabric as it dries, seals it against moisture, and provides a base surface for finish coats.
Question 3: Which inspection method is most effective for detecting fatigue cracks in aluminum wing skin that are not visible to the naked eye?
- Visual inspection with a 10x magnifier
- Eddy current inspection (Correct answer)
- Magnetic particle inspection
- Pressure differential testing
Correct answer: Eddy current inspection
Eddy current inspection detects subsurface and surface cracks in non-ferrous metals like aluminum without requiring surface preparation.
Question 4: What is the function of an anti-ice system on the leading edge of a wing?
- Remove ice that has already formed on the leading edge
- Prevent ice from forming on the leading edge surface (Correct answer)
- Detect ice formation and alert the crew
- Increase airflow velocity to shed ice
Correct answer: Prevent ice from forming on the leading edge surface
Anti-ice systems prevent ice from forming by heating or chemically treating the leading edge surface, while de-ice systems remove ice after it forms.
Question 5: When a technician finds that a turnbuckle in a control cable system is improperly safetied, what is the correct action?
- Re-safety using the available wire and return to service
- Remove the existing safety wire, verify thread engagement, and re-safety properly (Correct answer)
- Replace the turnbuckle and all adjacent cable
- Check cable tension only and log the discrepancy
Correct answer: Remove the existing safety wire, verify thread engagement, and re-safety properly
The turnbuckle must be checked for proper thread engagement (no more than 3 threads exposed), then re-safetied correctly per AC 43.13.
Question 6: What structural member in a semi-monocoque fuselage primarily resists torsional loads?
- Longerons
- Frames and bulkheads
- The stressed skin (Correct answer)
- Stringers
Correct answer: The stressed skin
In a semi-monocoque structure, the stressed skin carries the majority of torsional loads, distributing them across the fuselage surface.
Question 7: What is the maximum number of threads that may be exposed outside a turnbuckle barrel after adjustment?
- 1 thread
- 2 threads
- 3 threads (Correct answer)
- 4 threads
Correct answer: 3 threads
AC 43.13-1B specifies that no more than 3 threads may be exposed outside either end of a turnbuckle barrel after final adjustment.
Airframe Mechanic Certification Aircraft Systems & Components 5
What condition does a cracked or chafed pitot tube indicate regarding airworthiness?