Aviation Maintenance Terms beginning with J

Jet fuel

Fuel designed and produced to be used in aircraft gas turbine engines.

Jet propulsion

A method of propulsion by accelerating a relatively small mass of air through a large change in velocity.

Jeweler’s file

A small, fine-cut, metalworking file used by jewelry manufacturers.

Joule

A measure of energy. In terms of electrical energy, one joule is equal to one watt-second.

Journal (bearing)

A hardened and polished surface on a rotating shaft that rides in a plain bearing.