Flight Instruments is the groups of instrument for indicating the motion parameters (including linear and angular motion) of an aircraft in flight. Including air data instruments, heading instruments and attitude instruments.
B.
Engine instruments are used to check and indicate the engine operating conditions of the instrument, the main tachometer, pressure gauge, thermometer, flow meter, vibration indicator, etc..
C.
Auxiliary Instrument is the group of systems such as aircraft control system, air conditioning system, power supply system, hydraulic system, etc.. The main hydraulic pressure meter, voltmeter, frequency meter, etc..