FAA Part 107 Remote Pilot (UAG)Loading and PerformanceEasy
A client asks a remote pilot to attach a heavier sensor payload to a multirotor sUAS to collect more thorough imagery per flight. The pilot explains that adding this weight will affect flight time. What is the correct explanation?
- AFlight endurance increases because heavier aircraft require less throttle input to remain airborne
- BFlight endurance decreases because motors must produce more thrust to support the added weight, increasing current draw from the battery
- CFlight endurance increases because added weight improves aerodynamic stability, reducing power needed for control corrections
- DFlight endurance is unaffected by payload weight and depends only on battery voltage
Show answer & explanationAnswer & explanation
Correct answer: B. Flight endurance decreases because motors must produce more thrust to support the added weight, increasing current draw from the battery
Adding payload weight requires the motors to generate more thrust to maintain lift, which increases current draw from the battery and reduces overall flight endurance. This weight-versus-endurance tradeoff is a fundamental performance consideration for multirotor operations.
Why the other options are wrong
- A. Heavier aircraft need more, not less, throttle input to stay airborne.
- C. Added weight does not inherently improve stability or reduce power needs.
- D. Payload weight directly affects power demand and therefore endurance.
Weight vs. Endurance Tradeoff
Increasing payload weight on an sUAS requires more thrust and battery current, directly reducing available flight time.
- More weight = more thrust needed = more current draw
- Endurance and payload capacity are inversely related
- Pilots must balance mission payload needs against acceptable flight time
Memory trick: Heavier load, hungrier motors, shorter flight.