China Civil UAV Theory Questions — Questions 972–981

UAV-Q0972. When a remote-control UAV changes from a descent to level flight

Explanation

Study note: leveling off is always started before the planned altitude. Because of inertia, transitions among level flight, climb, and descent take time. When changing from a descent to level flight, therefore, begin leveling off 20-30 m before reaching the planned altitude.

UAV-Q0973. When a remote-control UAV at the planned altitude changes from level flight to a climb

Explanation

Pulling the stick raises the nose, changing level flight into a climb. Because a climb needs greater lift, the throttle must be increased (throttle 100%).

UAV-Q0974. When a remote-control UAV at the planned altitude changes from level flight to a descent

Explanation

Pushing the stick lowers the nose, changing level flight into a descent. In a descent, the aircraft's weight gradually increases its speed, so to maintain a suitable descent speed and descent rate, the pilot must reduce engine thrust by closing the throttle (throttle 15%).

UAV-Q0975. When a remote-control UAV at the planned altitude changes from a descent to level flight

Explanation

Pulling the stick raises the nose, changing a descent into level flight. Because the descent throttle is low (throttle 15%), changing to level flight requires more throttle (throttle 45%) to maintain enough speed and lift.

UAV-Q0976. When a remote-control UAV lands and reaches the float stage

Explanation

Early float: high speed, slow sink, small pull. Late float: low speed, fast sink, large pull, increasing the angle of attack to gain lift.

UAV-Q0977. The landing process of a remote-control UAV does NOT include

Explanation

Landing is divided into four stages: descent, flare, float-touchdown, and landing roll.

UAV-Q0978. When a remote-control UAV flares for landing, the inappropriate description of the flare action is

Explanation

Flight is affected by many factors, so the pilot must follow the actual situation and control the aircraft proactively, with foresight, and flexibly.

UAV-Q0979. When a remote-control UAV flares for landing, the relationship between pull speed and descent rate is

Explanation

Study note: fast goes with fast, slow goes with slow. If the descent is fast, flaring at the normal timing would flare too low, so the stick must be pulled earlier and faster.

UAV-Q0980. When a remote-control UAV flares for landing, the relationship between pull speed and descent rate is

Explanation

Study note: fast goes with fast, slow goes with slow. If the descent is slow, flaring at the normal timing would flare too high, so the stick must be pulled more slowly.

UAV-Q0981. When a remote-control UAV lands

Explanation

Study note: the wind holds the aircraft back, so it comes down early. Affected by wind, after the third turn the aircraft is pushed by the crosswind from the landing-field side and gradually moves away from the landing point. After the fourth turn, the glide distance and float distance are shortened by the headwind. A strong headwind therefore easily produces a visually low estimate (early touchdown).