FAA 107 Payload & Performance Calculations 5 — Questions and Answers
Question 1: A remote pilot conducts a hover test and finds the drone is consuming 180W to hover with a 1 lb payload versus 130W without. What is the approximate power penalty for carrying that payload?
- 50W or about 38% more power (Correct answer)
- 50W or about 72% more power
- 180W total, meaning full power is required
- No meaningful difference within FAA tolerances
Correct answer: 50W or about 38% more power
The increase is 180 − 130 = 50W, and 50 ÷ 130 × 100 ≈ 38% more power consumed due to the payload.
Question 2: A pilot needs to estimate remaining flight time with a new payload. Given: battery capacity = 5,000 mAh at 14.8V, average current draw with payload = 20A. What is approximate flight time?
- 15 minutes (Correct answer)
- 25 minutes
- 10 minutes
- 30 minutes
Correct answer: 15 minutes
Flight time = capacity (Ah) ÷ current (A) × 60 = 5.0 ÷ 20 × 60 = 15 minutes.
Question 3: Which best explains why payload placement fore or aft of the drone's center affects motor heating during sustained hover?
- Off-center payload forces asymmetric motor compensation, causing some motors to run hotter than others (Correct answer)
- Motor temperatures are controlled by the ESC regardless of payload position
- Fore/aft imbalance only affects GPS lock accuracy
- Payload position affects heating only during aggressive maneuvers, not hover
Correct answer: Off-center payload forces asymmetric motor compensation, causing some motors to run hotter than others
An imbalanced CG causes the flight controller to command higher throttle on one side to maintain level flight, overloading those motors.
Question 4: A drone has a thrust-to-weight ratio (TWR) of 2.0 at empty weight. After adding a payload, the TWR drops to 1.3. What is the most significant operational concern?
- A TWR near 1.0 leaves little margin for maneuvering, wind correction, or emergency climb (Correct answer)
- A TWR of 1.3 is ideal for efficient hover operations
- TWR below 2.0 triggers an automatic FAA waiver requirement
- Reduced TWR improves battery life proportionally
Correct answer: A TWR near 1.0 leaves little margin for maneuvering, wind correction, or emergency climb
A TWR close to 1.0 means the drone can barely maintain altitude, leaving insufficient power reserve for wind gusts, turns, or emergency responses.
Question 5: For a delivery sUAS, the term 'structural payload limit' differs from 'aerodynamic payload limit' in what way?
- Structural limit is set by frame/mount strength; aerodynamic limit is set by available motor thrust minus aircraft weight (Correct answer)
- Structural limit is always higher than aerodynamic limit on FAA-approved sUAS
- Both limits are identical and set solely by the FAA
- Aerodynamic limits apply only to fixed-wing drones
Correct answer: Structural limit is set by frame/mount strength; aerodynamic limit is set by available motor thrust minus aircraft weight
The structural limit is what the airframe and attachment points can physically bear, while the aerodynamic limit is the maximum weight the rotors can lift; the lower of the two governs.
Question 6: A remote pilot must carry a 1.5 lb inspection camera. To compensate for reduced endurance, which operational adjustment is most appropriate?
- Plan shorter flight legs and schedule additional battery swap intervals (Correct answer)
- Fly at maximum speed to cover the mission before battery depletion
- Increase altitude to reduce air density and improve efficiency
- Add a second battery in series to double voltage
Correct answer: Plan shorter flight legs and schedule additional battery swap intervals
Shorter legs with planned battery swaps are the safest and most practical way to manage reduced endurance when carrying heavier payloads.
Question 7: Under Part 107, if a remote pilot inadvertently loads a payload that brings the sUAS to 56 lbs at takeoff, what is required before the flight can legally occur?
- A Part 107 waiver authorizing operation of a sUAS above 55 lbs (Correct answer)
- A simple preflight log entry noting the excess weight
- Verbal approval from ATC at the nearest towered airport
- No additional action, as 56 lbs is within an acceptable tolerance band
Correct answer: A Part 107 waiver authorizing operation of a sUAS above 55 lbs
Any sUAS exceeding 55 lbs requires an FAA waiver under Part 107; there is no tolerance band above the 55 lb limit.
FAA 107 Payload & Performance Calculations 5
A remote pilot conducts a hover test and finds the drone is consuming 180W to hover with a 1 lb payload versus 130W without.
What is the approximate power penalty for carrying that payload?