FAA 107 Aircraft Maintenance & Pre-flight Inspection 5 — Questions and Answers
Question 1: What information should a remote pilot record in a maintenance log after replacing a motor on a sUAS?
- Only the date of replacement
- Date, nature of maintenance, parts used, and who performed the work (Correct answer)
- Serial number of the new motor only
- Maintenance logs are not required under Part 107
Correct answer: Date, nature of maintenance, parts used, and who performed the work
A thorough maintenance record includes the date, description of work, replacement parts, and the person who performed the work to establish a complete maintenance history.
Question 2: A pilot notices that the flight controller firmware update available is marked 'mandatory safety update.' What action should be taken?
- Update only if the current firmware is causing issues
- Apply the update before the next flight and verify all systems after updating (Correct answer)
- Ignore manufacturer updates until the current unit requires replacement
- Update during the flight to minimize downtime
Correct answer: Apply the update before the next flight and verify all systems after updating
Mandatory safety updates address known safety-critical bugs or vulnerabilities and must be applied before operating the aircraft to maintain airworthiness.
Question 3: Which of the following best describes 'range testing' as part of a sUAS pre-flight check?
- Flying the drone to maximum range to test signal strength at distance
- Verifying control link integrity at a reduced power setting according to manufacturer procedures (Correct answer)
- Testing how far the drone can fly on a full battery charge
- Checking the video feed quality at 500 feet away
Correct answer: Verifying control link integrity at a reduced power setting according to manufacturer procedures
Range testing uses a reduced transmitter power mode to simulate long-range signal conditions at close range, allowing verification of control link quality without actually flying far away.
Question 4: A remote pilot discovers that the propeller mounting nuts were over-tightened during the last maintenance session, causing thread damage. What is the appropriate response?
- Use additional lock washers to compensate for the damaged threads
- Replace the damaged hardware with manufacturer-approved fasteners before flying (Correct answer)
- Fly at reduced throttle settings to reduce propeller stress
- Apply thread-locking adhesive to secure the damaged threads
Correct answer: Replace the damaged hardware with manufacturer-approved fasteners before flying
Damaged threads cannot reliably secure propellers under flight loads and vibration, so stripped or damaged fasteners must be replaced with approved hardware before flight.
Question 5: What is the significance of checking the center of gravity (CG) on a sUAS before flight?
- CG affects only the aesthetics of flight, not safety
- An improperly balanced CG can cause unpredictable flight characteristics and reduce motor authority (Correct answer)
- CG only matters for fixed-wing aircraft, not multirotors
- CG shifts only occur when carrying external payloads above 2 pounds
Correct answer: An improperly balanced CG can cause unpredictable flight characteristics and reduce motor authority
An off-center CG forces some motors to work harder to maintain level flight, reduces maneuverability, and can cause the aircraft to flip if one motor reaches its limit.
Question 6: Under Part 107, who is responsible for ensuring a sUAS is in a condition for safe operation before each flight?
- The FAA through mandatory pre-flight certification checks
- The remote pilot in command (Correct answer)
- The manufacturer through scheduled maintenance programs
- The visual observer assigned to the flight
Correct answer: The remote pilot in command
Part 107.15 places the responsibility for ensuring the sUAS is in safe operating condition directly on the remote pilot in command before each flight.
Question 7: A remote pilot is about to fly in cold weather (below 32°F / 0°C). Which battery-related precaution is most important?
- Charge the battery to 100% to compensate for cold weather losses
- Pre-warm the batteries and expect reduced capacity and flight time (Correct answer)
- Use only alkaline batteries in cold weather instead of LiPo
- Cold weather has no effect on LiPo battery performance
Correct answer: Pre-warm the batteries and expect reduced capacity and flight time
LiPo batteries suffer significant capacity reduction in cold temperatures, and flying without pre-warming them can cause sudden voltage drop and unexpected power loss mid-flight.
FAA 107 Aircraft Maintenance & Pre-flight Inspection 5
What information should a remote pilot record in a maintenance log after replacing a motor on a sUAS?