China Civil UAV Theory Questions — Questions 94–103

Study note: 1 km for runway lights, 2 km for obstacle lights.

A situation that directly leads to a crash is a critical situation; a situation that does not directly lead to a crash is an emergency situation. A flight control system failure prevents correct control of the aircraft and directly leads to a crash. An uplink communication link failure means control station commands cannot reach the UAV, but it may trigger automatic return or automatic hover, and does not directly lead to a crash. With a control station display system failure, the uplink for control commands is unaffected, and it does not directly lead to a crash.

A situation that directly leads to a crash is a critical situation; a situation that does not directly lead to a crash is an emergency situation. A mission equipment failure does not affect flight and does not directly lead to a crash.

Emergency procedures mainly resolve critical situations: (1) powerplant restart operation - powerplant failure [critical]; (2) backup system switchover operation - flight control, electrical, or control station control system failures [critical]; (3) forced landing operation - applicable to various [critical] situations.

Conformal means angles are equal, that is, angles are undistorted. Further knowledge: a conformal projection chart, also called an orthomorphic projection or similar projection, is one on which the angle between any two direction lines at any point equals the corresponding angle on the ground. Small-area shapes on the chart remain similar to those on the ground. In a conformal projection, meridians and parallels are orthogonal, the distortion ellipse is a circle of varying size, and the maximum angular distortion, w, is zero. Conformal projections are mostly used for maps requiring high directional accuracy, such as traffic maps, ocean current maps, wind maps, nautical charts, aeronautical charts, meteorological maps, and military maps.

A civil UAV system requires inspection at least once a year. The inspection should be performed by a certificated person holding inspection authorization, or by the manufacturer, or by a certificated and properly evaluated maintenance station.

2 km = 2,000 m = 200,000 cm. Using the scale: 200,000 x (1/100,000) = 2 cm.

Study note: small pitch, high rpm at takeoff. A variable-pitch propeller is one whose blade angle can be changed in flight, automatically or manually, according to flight speed and altitude. At takeoff, forward speed is low, and the variable-pitch device reduces the propeller blade angle - that is, small pitch - so that the engine works at maximum rpm and maximum power, and the propeller produces maximum thrust. In level flight, the variable-pitch mechanism can set the pitch to the high pitch suited to that flight condition, at which, at maximum rpm, the propeller obtains maximum useful power from the engine. A variable-pitch propeller can therefore use the engine's maximum effective power at any flight speed.

Civil Aviation Flight Rules of China, Article 80: flight time means the time from when an aircraft, in preparation for takeoff, begins to move under its own power from the loading point until the flight ends and movement stops at the unloading point. Takeoff time means the instant the aircraft begins its takeoff roll and its wheels move; landing time means the instant the aircraft's landing rollout ends. Helicopter flight time means the time from when the rotor starts turning until the rotor stops turning. Helicopter takeoff time and landing time mean the instants the main wheels (skids) leave the ground and touch the ground.

Source: Civil Aviation Flight Rules of China. Traffic-pattern flight altitude is usually 300-500 m. After takeoff, the altitude at the beginning of the first turn and at the end of the fourth turn shall not be below 100 m, and in complex meteorological conditions or at night shall not be below 150 m.