What is an aircraft jack? Are you talking about lifting the wheels during takeoff and landing? If that’s the case I would say not lOLAR as they are not lifting the load – I would count the wheel as part of the equipment – Look at the HSE examples https://www.hse.gov.uk/work-equipment-machinery/lift-equipment.htm so a bit like the roller shutter door – If however its something that you use separately to lift the aircraft off the floor for maintenance, etc then I would say LOLAR.

Wheeled or unwheeled jacks?

Full clear lift or support only?

Aircraft jacks are usually hydraulic in operation. A hand pump on the side, to pump oil into the lifting ram. The ram has an lifting adaptor slotted into the top that locates in to the jacking point on the underside of the aircraft.

To stabilse the jacks, thay have 4 legs which after lifting the aircraft are then adjusted to take up the weight of the aircraft off the hydraulic fluid. A locking collar is then screwed down the hydraulic ram, and locks/sits against the body of the jack to provide a mechanical lock to prevent the aircraft descending if the hydraulic ram fails. 

LOLER inspections are required.

Aircraft are raised on jacks for a variety of reasons

to change wheels or brake units (often just a small leg that compresses the undercarriage oleo to lift the wheel clear of the grounf.

to replace faulty undercarriage legs

to test / check the function of the undercarriage

to allow the aircraft to be rigged - to check the wing dihedral

to replace wings

after heavy/hard landings to chack for damage

to check weapons electrical circuits, if for some reason the weapons system scotch is not available