AET Maintenance Procedures and Safety 3 — Questions and Answers
Question 1: Under FAR Part 43, which task performed on an aircraft avionics system requires a Major Repair or Alteration form (FAA Form 337)?
- Replacing a like-for-like GPS antenna with the same part number
- Installing a new avionics system not previously approved for the aircraft (Correct answer)
- Cleaning and re-seating a connector on the autopilot
- Performing a functional check of existing equipment
Correct answer: Installing a new avionics system not previously approved for the aircraft
Installing a new avionics system not previously approved for the aircraft constitutes a major alteration requiring FAA Form 337.
Question 2: A technician is testing an aircraft transponder on the bench. What hazard does the transponder's RF output present?
- Risk of data corruption to nearby avionics
- Electromagnetic radiation hazard to personnel and potential interference with ATC (Correct answer)
- Fire risk from the antenna port
- Damage to the bench power supply
Correct answer: Electromagnetic radiation hazard to personnel and potential interference with ATC
Active transponders emit RF energy that can cause electromagnetic radiation hazards to nearby personnel and interfere with ATC radar systems.
Question 3: When using a heat gun on aircraft wiring during shrink-tubing installation, the MOST important precaution is:
- Use only FAA-approved heat guns
- Keep the heat gun moving and avoid concentrating heat on one spot (Correct answer)
- Apply heat from the center outward
- Disconnect the battery before applying heat
Correct answer: Keep the heat gun moving and avoid concentrating heat on one spot
Keeping the heat gun moving prevents localized overheating that could melt wire insulation or damage nearby components.
Question 4: What is the correct procedure when a technician accidentally drops a tool inside an aircraft during avionics maintenance?
- Complete the maintenance task first, then retrieve the tool
- Immediately stop work and retrieve the tool, documenting the event (Correct answer)
- Note the tool's location and retrieve it during next access
- Notify the pilot but continue maintenance
Correct answer: Immediately stop work and retrieve the tool, documenting the event
A dropped tool must be immediately retrieved and the event documented, as a loose tool can jam flight controls or cause electrical hazards.
Question 5: Which OSHA standard primarily governs electrical safety for aviation maintenance technicians working on aircraft electrical systems?
- OSHA 29 CFR 1910.303 – General Electrical Requirements
- OSHA 29 CFR 1910.147 – Control of Hazardous Energy (Lockout/Tagout) (Correct answer)
- OSHA 29 CFR 1926.416 – Electrical Construction
- OSHA 29 CFR 1910.269 – Electric Power Generation
Correct answer: OSHA 29 CFR 1910.147 – Control of Hazardous Energy (Lockout/Tagout)
OSHA 29 CFR 1910.147 (Lockout/Tagout) governs the control of hazardous energy during maintenance, directly applicable to aircraft electrical systems.
Question 6: After completing avionics maintenance, a technician notices the aircraft skin has several small scratches near the avionics bay access panel. The CORRECT action is to:
- Polish the scratches with abrasive compound and return to service
- Document the damage in the maintenance record and defer to sheet metal inspection (Correct answer)
- Ignore scratches smaller than 1/8 inch
- Apply touch-up paint immediately to prevent corrosion
Correct answer: Document the damage in the maintenance record and defer to sheet metal inspection
Any new airframe damage found during maintenance must be documented and assessed by qualified personnel before return to service.
Question 7: What is the purpose of using a 'dummy load' when testing an aircraft radio transmitter on the bench?
- To simulate antenna impedance and prevent unauthorized RF emissions (Correct answer)
- To boost the transmitter's output power for testing
- To protect the bench test equipment from DC voltage spikes
- To simulate cockpit audio panel loading
Correct answer: To simulate antenna impedance and prevent unauthorized RF emissions
A dummy load absorbs transmitted RF energy, simulating antenna impedance while preventing unauthorized or hazardous radio frequency emissions into the environment.
AET Maintenance Procedures and Safety 3
Under FAR Part 43, which task performed on an aircraft avionics system requires a Major Repair or Alteration form (FAA Form 337)?