Airframe Mechanic Certification Safety Procedures & Regulatory Compliance 3 — Questions and Answers
Question 1: When working near aircraft fuel systems, which type of fire extinguisher is most appropriate to have immediately available?
- Class A (water) extinguisher
- Class B (CO2 or dry chemical) extinguisher (Correct answer)
- Class C (halon) extinguisher for electrical fires only
- Class D extinguisher for metal fires
Correct answer: Class B (CO2 or dry chemical) extinguisher
Class B fire extinguishers, which include CO2 and dry chemical types, are designed for flammable liquid fires such as fuel and are the appropriate choice near aircraft fuel systems.
Question 2: What is the primary purpose of bonding in aircraft maintenance?
- To strengthen structural joints between dissimilar metals
- To provide an electrical path to prevent static charge buildup (Correct answer)
- To seal control surface hinges against moisture intrusion
- To secure safety wire on critical fasteners
Correct answer: To provide an electrical path to prevent static charge buildup
Bonding provides a low-resistance electrical path between metallic components to prevent static charge buildup that could cause sparks, interference, or corrosion.
Question 3: A mechanic is about to perform maintenance on a pressurized aircraft fuel line. What is the FIRST step before opening any fittings?
- Don rubber gloves and safety glasses
- Ensure the fuel system pressure is relieved (Correct answer)
- Place absorbent material under the work area
- Tag out the fuel pump circuit breaker
Correct answer: Ensure the fuel system pressure is relieved
Before opening any pressurized fuel line fitting, the system pressure must be fully relieved to prevent fuel spray and potential fire or injury.
Question 4: Under 14 CFR Part 39, when an Airworthiness Directive specifies a compliance time of '50 hours TIS,' what does TIS stand for?
- Time in storage
- Time in service (Correct answer)
- Technical inspection standard
- Total indicated speed
Correct answer: Time in service
TIS stands for Time in Service, which refers to the total flight time accumulated by the aircraft or affected component.
Question 5: Which of the following correctly describes a preventive maintenance item that a certificated pilot may perform?
- Replacing a landing gear assembly
- Replacing defective safety wiring
- Troubleshooting and repairing avionics
- Repacking wheel bearings (Correct answer)
Correct answer: Repacking wheel bearings
14 CFR Part 43, Appendix A lists repacking wheel bearings as a preventive maintenance item that certificated pilots may perform on aircraft they own or operate.
Question 6: What does the term 'return to service' specifically mean in the context of 14 CFR Part 43?
- The aircraft has been refueled and is ready for the next flight
- An authorized individual has approved the aircraft as airworthy after maintenance (Correct answer)
- The aircraft has completed its scheduled annual inspection
- The aircraft has been repositioned from the hangar to the ramp
Correct answer: An authorized individual has approved the aircraft as airworthy after maintenance
Return to service occurs when an authorized person approves and signs off that the aircraft is airworthy following maintenance, preventive maintenance, or alteration.
Question 7: When should a mechanic apply a placard reading 'DO NOT OPERATE' to an aircraft?
- When the aircraft is due for its annual inspection
- When the aircraft is stored for more than 30 days
- When the aircraft has a known unairworthy condition that has not been corrected (Correct answer)
- Whenever performing scheduled maintenance exceeding 2 hours
Correct answer: When the aircraft has a known unairworthy condition that has not been corrected
A 'DO NOT OPERATE' or similar placard is applied to notify crew members that the aircraft has an unresolved unairworthy condition that makes it unsafe to fly.
Airframe Mechanic Certification Safety Procedures & Regulatory Compliance 3
When working near aircraft fuel systems, which type of fire extinguisher is most appropriate to have immediately available?