FAA 107 Payload & Performance Calculations 3 — Questions and Answers
Question 1: A drone's hover efficiency is expressed as grams of thrust per watt. How does adding payload affect this metric?
- Efficiency decreases because more watts are consumed to lift each additional gram (Correct answer)
- Efficiency increases because heavier drones are more aerodynamically stable
- Efficiency remains constant regardless of payload
- Efficiency increases because motors run at optimal RPM under load
Correct answer: Efficiency decreases because more watts are consumed to lift each additional gram
Adding payload requires more power for the same lift, so the system produces fewer grams of net useful lift per watt consumed.
Question 2: A remote pilot plans to fly a mapping mission with a drone carrying a thermal camera. The manufacturer states maximum payload is 1.5 lbs. The camera weighs 1.3 lbs. What should the pilot assess before flight?
- Whether the reduced payload margin leaves enough buffer for safe maneuvering and wind gusts (Correct answer)
- Whether the FAA requires a waiver for thermal camera payloads
- Whether flying near 1.5 lbs requires a night operations waiver
- Whether total aircraft weight exceeds 55 lbs regardless of payload margin
Correct answer: Whether the reduced payload margin leaves enough buffer for safe maneuvering and wind gusts
Operating near the payload limit reduces handling margins; pilots must assess whether the aircraft can safely maneuver with the added weight in expected conditions.
Question 3: Which formula correctly calculates the payload capacity of a drone?
- Maximum Takeoff Weight − Empty Weight (including batteries) (Correct answer)
- Empty Weight − Payload Weight
- Maximum Takeoff Weight ÷ Empty Weight
- Thrust − Drag
Correct answer: Maximum Takeoff Weight − Empty Weight (including batteries)
Payload capacity is what remains of MTOW after subtracting the drone's own weight including batteries and fixed equipment.
Question 4: How does center of gravity (CG) shift caused by payload placement affect sUAS flight?
- It can cause the drone to be nose-heavy or tail-heavy, degrading stability and control (Correct answer)
- CG only matters for fixed-wing aircraft, not multirotors
- Payload placement affects only forward speed, not stability
- A shifted CG automatically corrects itself via GPS stabilization
Correct answer: It can cause the drone to be nose-heavy or tail-heavy, degrading stability and control
An improperly positioned payload shifts the CG, forcing flight controllers to compensate and potentially degrading handling or exceeding control authority.
Question 5: A drone carrying a heavier-than-usual payload experiences reduced climb rate. What is the primary aerodynamic reason?
- The excess thrust available above hover decreases when more power is consumed maintaining lift (Correct answer)
- Heavier aircraft have lower propeller disc loading
- Payload weight increases rotor efficiency proportionally
- Climb rate is determined by battery voltage alone
Correct answer: The excess thrust available above hover decreases when more power is consumed maintaining lift
Climb rate depends on excess thrust beyond hover; heavier payloads consume more of the available thrust for hovering, leaving less for climbing.
Question 6: A remote pilot is asked to carry a 1 lb sensor. The drone weighs 3 lbs with battery and its MTOW is 3.5 lbs. What should the pilot do?
- Decline the flight because the total weight of 4 lbs exceeds the 3.5 lb MTOW (Correct answer)
- Accept the flight since total weight is under 55 lbs
- Accept if the flight is under 200 feet AGL
- Request a waiver from the FAA before proceeding
Correct answer: Decline the flight because the total weight of 4 lbs exceeds the 3.5 lb MTOW
3 lbs + 1 lb payload = 4 lbs, which exceeds the drone's 3.5 lb MTOW, making the flight unsafe and non-compliant with manufacturer limits.
Question 7: In performance planning, the term 'useful load' on a sUAS most accurately refers to:
- The weight of payload and any non-permanent accessories the drone can carry beyond its empty weight (Correct answer)
- The total weight the drone can produce in thrust
- The weight saved by using lighter batteries
- The difference between certified MTOW and FAA's 55 lb limit
Correct answer: The weight of payload and any non-permanent accessories the drone can carry beyond its empty weight
Useful load is the weight available for payload and removable equipment after accounting for the drone's empty (tare) weight.
FAA 107 Payload & Performance Calculations 3
A drone's hover efficiency is expressed as grams of thrust per watt.
How does adding payload affect this metric?