FAA 107 Payload & Performance Calculations 4 — Questions and Answers
Question 1: A remote pilot calculates that adding a 0.9 lb payload reduces flight time from 28 minutes to 19 minutes. What is the approximate percentage reduction in endurance?
- 32% (Correct answer)
- 18%
- 47%
- 9%
Correct answer: 32%
(28 − 19) ÷ 28 × 100 = 32.1%, so the drone loses approximately 32% of its endurance.
Question 2: Which of the following best describes disc loading in the context of drone payload performance?
- Total thrust divided by the total rotor disc area, which increases with added payload (Correct answer)
- The maximum weight the landing gear can support
- The ratio of payload weight to total drone weight
- The power consumed by the ESC under full throttle
Correct answer: Total thrust divided by the total rotor disc area, which increases with added payload
Disc loading (thrust/rotor area) rises with payload weight because more thrust must be generated across the same rotor area.
Question 3: A pilot carries a 0.5 lb payload on a hot day (DA 4,000 ft). Compared to sea level standard conditions, what should the pilot expect?
- Reduced available thrust, requiring higher throttle and greater battery draw to carry the same payload (Correct answer)
- Identical performance since payload weight is independent of density altitude
- Improved efficiency because thinner air reduces aerodynamic drag on the frame
- Lower motor temperatures because air is cooler at higher density altitudes
Correct answer: Reduced available thrust, requiring higher throttle and greater battery draw to carry the same payload
High density altitude reduces air density, which decreases rotor efficiency; motors must work harder to produce the same lift, especially under payload.
Question 4: A commercial sUAS operation requires lifting a 2.2 lb sensor to 300 ft AGL in calm winds. Which specification is most critical to verify before flight?
- That the payload is within the drone's rated payload capacity and the total MTOW is under 55 lbs (Correct answer)
- That the drone has a minimum of 8 motors
- That the drone's FPV camera is operational
- That the operation takes place before noon local time
Correct answer: That the payload is within the drone's rated payload capacity and the total MTOW is under 55 lbs
Confirming payload is within rated capacity and total weight is under 55 lbs ensures both manufacturer safety and FAA Part 107 compliance.
Question 5: A drone manufacturer publishes payload capacity at sea level standard conditions. How should this data be interpreted for a flight at 5,000 ft density altitude?
- The actual safe payload will be less than the published figure due to reduced rotor efficiency at higher density altitude (Correct answer)
- The payload capacity doubles at higher elevations due to reduced gravity
- Manufacturer data is valid at all altitudes for sUAS
- Higher altitude improves motor cooling, maintaining rated payload capacity
Correct answer: The actual safe payload will be less than the published figure due to reduced rotor efficiency at higher density altitude
Rated capacity is measured in standard sea-level conditions; at higher density altitude, reduced air density decreases rotor efficiency and effective payload capacity.
Question 6: A 4.4 lb sUAS (including battery) is asked to carry a package. The pilot determines total MTOW will be 5.8 lbs, still well under 55 lbs. Which statement is correct?
- The flight may still be unsafe if 5.8 lbs exceeds the manufacturer's rated MTOW for that aircraft (Correct answer)
- The flight is fully compliant because it is under the FAA 55 lb limit
- The FAA 55 lb rule overrides manufacturer limits for commercial operations
- A waiver is required for any payload flight over 4 lbs
Correct answer: The flight may still be unsafe if 5.8 lbs exceeds the manufacturer's rated MTOW for that aircraft
The FAA's 55 lb limit does not override manufacturer MTOW ratings; exceeding the aircraft's rated MTOW is unsafe regardless of the regulatory ceiling.
Question 7: What effect does increasing payload weight have on a multirotor's agility and response to control inputs?
- Agility decreases because greater inertia requires more torque to change attitude (Correct answer)
- Agility increases because heavier drones have more momentum
- Payload has no effect on control response in GPS mode
- Control response improves due to increased gyroscopic stability
Correct answer: Agility decreases because greater inertia requires more torque to change attitude
Higher payload increases the system's rotational inertia, requiring more motor torque to execute the same maneuvers, which slows control response.
FAA 107 Payload & Performance Calculations 4
A remote pilot calculates that adding a 0.9 lb payload reduces flight time from 28 minutes to 19 minutes.
What is the approximate percentage reduction in endurance?