Aviation Machinist's Mates (AD) maintain aircraft engines and their related systems, including the induction, cooling, fuel, oil, compression, combustion, turbine, gas turbine compressor, exhaust and propeller systems; preflight aircraft; conduct periodic inspections on engines and engine-related systems; field-test and adjust engine components, including fuel controls, pumps, valves and regulators; remove, repair and replace compressor and turbine blades and combustion chamber liners; preserve and depreserve engines, engine accessories and components; and supervise engine work centers.