ABSOLUTE ALTITUDE, The actual distance the aircraft is above the ground.
ALTITUDE, the actual distance between the aircraft and the ground.
ABSOLUTE PRESSURE, Pressure of a liquid or gas measured relative to a vacuum.
Absolute pressure, the pressure of liquid or gas, measured relative to vacuum.
ACARS, SEE - AIRCRAFT (OR ARINC) REPORTING ADDRESSING AND COMMUNICATION SYSTEM
ACARS, see-on-board (or ARINC) communication system, and addressing messages.
ACCELERATION, The rate of change in velocity with respect to time.
Acceleration speed derivative with respect to time.
ACCESSORY GEARBOX (Figure 1), A part of the engine, mechanically driven by a compressor or an angle gearbox, for driving components necessary for engine and airplane operations.
Gearbox with accessories of the motor is mechanically driven by a compressor or a bevel gear to drive the elements necessary for the operation of the engine or the aircraft.