UAS Maintenance 2 — Questions and Answers
Question 1: What is the primary purpose of inspecting propeller blades before each flight?
- To check blade color for UV degradation
- To detect nicks, cracks, or delamination that could cause failure (Correct answer)
- To verify blade pitch matches manufacturer specs
- To measure blade weight for balance certification
Correct answer: To detect nicks, cracks, or delamination that could cause failure
Propeller blades must be inspected for nicks, cracks, or delamination before each flight because structural defects can cause catastrophic in-flight failure.
Question 2: When should a UAS battery be removed from service?
- After exactly 100 charge cycles regardless of condition
- When the battery shows signs of puffing, swelling, or reduced capacity (Correct answer)
- Only when the battery fails to charge completely
- After 12 months from the purchase date
Correct answer: When the battery shows signs of puffing, swelling, or reduced capacity
A battery showing puffing, swelling, or significant capacity loss is a safety hazard and must be removed from service immediately.
Question 3: What does a visual inspection of motor mounts primarily check for?
- Motor temperature rating
- Loose fasteners, cracks, or signs of vibration damage (Correct answer)
- Magnetic field alignment of the motor
- Motor RPM calibration accuracy
Correct answer: Loose fasteners, cracks, or signs of vibration damage
Motor mount inspections focus on loose fasteners, cracks, and vibration damage because compromised mounts can cause motor separation during flight.
Question 4: How should a UAS operator handle a flight controller firmware update?
- Install updates immediately during a field operation
- Update without testing if the manufacturer recommends it
- Update in a controlled environment and verify calibration before flight (Correct answer)
- Avoid all firmware updates to maintain system stability
Correct answer: Update in a controlled environment and verify calibration before flight
Firmware updates should be applied in a controlled environment, followed by full calibration verification before returning to operational flights.
Question 5: What is the correct storage condition for LiPo batteries when not in use for extended periods?
- Fully charged at 4.2V per cell in a warm location
- Completely discharged to 0V per cell in a sealed bag
- Storage voltage of approximately 3.8V per cell in a cool, dry location (Correct answer)
- At 50% charge in direct sunlight to maintain cell memory
Correct answer: Storage voltage of approximately 3.8V per cell in a cool, dry location
LiPo batteries stored at approximately 3.8V per cell in a cool, dry environment maintain optimal health and longevity.
Question 6: Which maintenance action should follow any hard landing or crash?
- Immediately resume flight if no visible damage is present
- Conduct a full structural inspection before the next flight (Correct answer)
- Only inspect the landing gear and replace if bent
- File a report and fly again after a 24-hour waiting period
Correct answer: Conduct a full structural inspection before the next flight
A full structural inspection after any hard landing or crash is mandatory because internal damage may not be visible externally.
Question 7: What is the purpose of performing an ESC calibration on a multirotor UAS?
- To sync the maximum and minimum throttle signal range across all ESCs (Correct answer)
- To update ESC firmware to the latest version
- To measure the amperage draw of each motor
- To align motor magnetic poles for reduced heat
Correct answer: To sync the maximum and minimum throttle signal range across all ESCs
ESC calibration synchronizes the throttle input range across all electronic speed controllers, ensuring consistent motor response and stable flight.
UAS Maintenance 2
What is the primary purpose of inspecting propeller blades before each flight?