Definition
A piece of ground support equipment used to extend and retract an aircraft's landing gear during maintenance, inspection, or rigging while the aircraft is raised on jacks. It supports the aircraft so the wheels are off the ground, allowing the gear to be cycled through its full range of motion without the weight of the aircraft on it.
Plain English
A special jack that holds the aircraft up off the ground so mechanics can raise and lower the landing gear repeatedly to test it or work on it.
Context Anchor
Seen in aircraft maintenance, especially during landing gear checks or shock strut servicing.
Derivation
Exerciser' comes from 'exercise,' meaning to put through a range of motion or activity. The jack 'exercises' the landing gear by allowing it to be cycled up and down repeatedly during maintenance.
Why Pilots Care
Confirms that landing gear and flight controls will operate correctly before flight, catching hydraulic problems that could otherwise appear in the air.
Analogy
It is like slowly moving a stiff door open and closed to check whether the hinges move smoothly, except the exerciser jack supplies the controlled force for an aircraft part.
Intuition Check
Do not read “exerciser” as a training device for a pilot. In this term, it means a tool that moves an aircraft part through its normal motion for checking or servicing.
Example Sentence 1
Before signing off the gear inspection, the mechanics placed the aircraft on exerciser jacks to cycle the landing gear several times.
Example Sentence 2
Using the exerciser jack, the technician cycled the flaps through their full range to confirm smooth operation before returning the aircraft to service.