Aircraft Jacks

There are many different types of aircraft jacks currently in use, however, they all fall into two groups, mechanical and hydraulic.

Mechanical Lifting Jacks

The mechanical jacks operate on a simple ‘screw jack’ principle, where a ratchet mechanism is used to raise the telescopic ram by use of a square thread.  These jacks are usually only used for raising small light aeroplanes, and some helicopters.

Hydraulic Lifting Jacks

The majority of aircraft lifting jacks operate on a hydraulic principle, which use the fact that oil will flow freely yet act as a solid, because it is in this context incompressible.  Another advantage of using the hydraulic principle, is that a relatively small piston pump can generate a lot of pressure to move the jack ram and aircraft upwards, with only a moderate effort on the part of the operator.