UAG - Unmanned Aircraft General UAS Loading and Performance Questions and Answers — Questions and Answers
Question 1: A remote pilot is preparing for a flight on a hot, humid day at an airport with a high field elevation. Which of the following effects on UAS performance should be anticipated?
- Increased propeller efficiency and longer flight times.
- Decreased takeoff distance and improved climb performance.
- Reduced aircraft performance due to high density altitude. (Correct answer)
- No significant impact on performance, as UAS are unaffected by density altitude.
Correct answer: Reduced aircraft performance due to high density altitude.
High temperature, high humidity, and high elevation all contribute to a high density altitude. High density altitude means the air is less dense, which reduces the efficiency of the propellers and motors. This leads to decreased overall aircraft performance, including longer takeoff distances, reduced climb rates, and shorter flight times.
Question 2: If the center of gravity (CG) of a fixed-wing unmanned aircraft is moved to the most aft limit, which performance characteristic is most likely to be experienced?
- Increased longitudinal stability and higher stall speed.
- Less stability and a lower stall speed. (Correct answer)
- Improved stall recovery characteristics.
- A requirement for less tail-down force to maintain level flight, leading to increased drag.
Correct answer: Less stability and a lower stall speed.
Moving the center of gravity (CG) aft decreases longitudinal stability, making the aircraft less stable but more maneuverable. An aft CG also results in a lower stall speed because less tail-down force is required to balance the aircraft, which means the wing can fly at a lower angle of attack for level flight.
Question 3: What is the primary reason a remote pilot in command must calculate the weight and balance of their UAS before every flight?
- To ensure the UAS does not exceed the 100 mph speed limit.
- To verify the battery is fully charged.
- To comply with the manufacturer's specified limits for safe operation. (Correct answer)
- To determine the maximum flight altitude for the mission.
Correct answer: To comply with the manufacturer's specified limits for safe operation.
Compliance with the manufacturer's specified weight and balance limits is critical for flight safety. Operating outside these limits can compromise the structural integrity of the aircraft and lead to instability or loss of control. The remote PIC is responsible for verifying the aircraft is correctly loaded before each flight.
Question 4: During a coordinated 60-degree banked turn, the load factor on a UAS would be approximately:
- 1 G
- 1.5 Gs
- 2 Gs (Correct answer)
- 3 Gs
Correct answer: 2 Gs
In a coordinated, level turn, the load factor increases with the angle of bank. The load factor is the ratio of the total lift produced to the aircraft's weight. In a 60-degree bank, the lift required to maintain altitude is twice the weight of the aircraft, resulting in a load factor of 2 Gs.
Question 5: A remote pilot plans to attach a new, heavier camera payload to their multirotor UAS. Which of the following is the most significant performance change the pilot should expect?
- Increased maneuverability and faster response to control inputs.
- Longer flight endurance due to increased momentum.
- A lower center of gravity, which always improves stability.
- Decreased flight endurance and potentially sluggish control response. (Correct answer)
Correct answer: Decreased flight endurance and potentially sluggish control response.
Exceeding the maximum gross weight of a UAS reduces flight performance in almost every respect. The motors must work harder to generate sufficient lift, which significantly increases power consumption and decreases flight endurance. The added weight also increases inertia, which can make the aircraft feel less responsive or 'sluggish' to control inputs.
Question 6: When reviewing a takeoff performance chart in the UAS Flight Manual, what is the effect of a headwind?
- It increases the takeoff distance required.
- It has no effect on takeoff distance.
- It decreases the takeoff distance required. (Correct answer)
- It requires a higher rotation speed.
Correct answer: It decreases the takeoff distance required.
A headwind reduces the groundspeed the aircraft must achieve to reach its liftoff airspeed. Because the aircraft has a 'head start' in terms of airflow over the wings, the ground roll distance required for takeoff is decreased.
UAG - Unmanned Aircraft General UAS Loading and Performance Questions and Answers
A remote pilot is preparing for a flight on a hot, humid day at an airport with a high field elevation.
Which of the following effects on UAS performance should be anticipated?