China Civil UAV Theory Questions — Questions 84–93

Flight levels are used to coordinate the relative altitudes of different flights, so a common standard is needed. Standard atmospheric pressure assumes sea level as the common standard usable by all flights. Standard atmospheric pressure is 1013 hPa, so C is correct. Basic Rules of Flight of the People's Republic of China, Article 80: ... (3) flight levels shall be calculated on the basis of the assumed sea level under standard atmospheric pressure conditions. The true course angle shall be measured from the route starting point and turning points.

Flight altitude is the vertical distance from the aircraft to a reference plane (such as sea level or the airport plane), and it varies with the reference plane.

On touchdown, the aircraft has a large horizontal speed component, but during rollout, aerodynamic drag and wheel rolling resistance have a relatively small decelerating effect on the aircraft. Option C is the cause of damage from a braked touchdown. Options A and B are manifestations (results) of the damage.

Option B covers A and C, and its definition is clear and complete. Option A, touching down too quickly, means the touchdown speed is too high; it is one manifestation of a hard landing, and the definition is incomplete. Option C, nose wheel touching first, means the touchdown angle is unreasonable; it is one manifestation of a hard landing, and the definition is incomplete.

Basic Principles of Flight of the People's Republic of China, Article 49: a pilot starting the engine and taxiing must have permission from the air traffic controller or flight commander. When taxiing or towing, the following rules shall be observed: (1) taxi or tow along the prescribed route or the route designated by the air traffic controller or flight commander; (2) taxi speed shall follow the flight manual or pilot operating handbook for the aircraft concerned; when taxiing near obstacles, the speed shall not exceed 15 km per hour. ...

When an aircraft enters a climb, its flight path changes from level flight to a climb attitude inclined to the horizontal. In a climb, gravity no longer acts perpendicular to the flight path; it acts backward. This increases total drag, requiring increased power to balance the drag, so engine output increases and the engine is more likely to overheat.

Study note: prolonged idle running fouls the spark plugs. Idle is the minimum steady continuous rpm at which the engine operates. Idle applies to landing, rapid descent, ground taxiing, and similar situations. At idle, the fuel-air mixture is relatively rich and engine temperature is low, so spark plugs easily accumulate carbon deposits, engine stability is poor, and idle should not be prolonged.

The three methods for calculating loading weight and center of gravity are the calculation method, the chart method, and the table lookup method.

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.

Textbook p. 282, to be memorized directly: preventive maintenance every 20 hours or less, and minor maintenance every 50 hours.