AIRPLANE INSTRUMENT MECHANIC (686)
Tests and analyzes the functioning of aircraft instruments to reveal defective units.
Examines exterior of instruments for cleanliness, security of mountings and connections, tightness of electrical binding, condition of cases, vibration absorbers, and cover glasses. Checks instrument pointers for excessive oscillation, proper zero setting, and correct indication.
Uses combination test set to analyze operation of electrical instruments. Observes operation of gyro-operated instruments in various positions and locates such faults as worn bearings. Notes whether readings of pressure instruments are consistent with factors measured. Replaces instruments when faulty operation is caused by defective internal mechanism.
Services the directional gyro, gyro horizon instruments, and automatic pilots. Checks oil in dash pots of automatic pilot and inspects and adjusts the air relays, balanced oil valves, pressure regulators, suction regulators, servos, and oil pumps of the unit.