SXDFC From United States of America, joined Dec 2007, 2325 posts, RR: 21 Posted (5 years 8 months 2 weeks 6 days 3 hours ago) and read 7745 times:
In many MX pictures on this site, and else where I have seen planes on hydraulic lifts under the wing and on the side of the plane. I would like to know how these devices work, especially the ones that are placed on the side of the plane. Is it a powered magnet that attaches to the skin of the plane?
ALL views, opinions expressed are mine ONLY and are NOT representative of those shared by Southwest Airlines Co.
TristarSteve From Sweden, joined Nov 2005, 4001 posts, RR: 34
Reply 1, posted (5 years 8 months 2 weeks 6 days 3 hours ago) and read 7736 times:
I think you are talking about jacks, where the aircraft is jacked off the wheels for maint.
The jacks fit into special jacking pads. These are usually fitted by removing a panel and bolting the pad onto the aircraft. Sometimes there is no panel to remove at the nose. The six bolt holes are filled with plastic inserts that are removed. The jacking pads are kept with the jacks and are special for each aircraft type.
DALMD88 From United States of America, joined Jul 2000, 2546 posts, RR: 14
Reply 2, posted (5 years 8 months 2 weeks 6 days 3 hours ago) and read 7732 times:
For the nose jacks on planes like a 757/767 the jack mount fixture is screwed into mount holes on the side of the plane. When not is use the holes are plugged with flush screws. The jack mounts for the wing jacks screw into similar holes under the wing. Some aircraft, like the MD80 use this type for the nose and tail also. Magnets wouldn't work too good. Aluminum structure isn't very attracted to magnets.
The jacks themselves are actuated by shop compressed air. You simply step on the lever and they slowly pump up. Just like a pump type bottle jack you might use on a car. Care must be taken when jacking that the plane goes up level. There are bubble gages mounted in the wheel wells to show the condition.
Sounds like you are reffering to aircraft hydraulic jacks.
These are hydraulically operated,screw jack ring locked at small intervals of lift to cater to a loss of fluid.
Placed at four points around the aircraft "normally".
There is a level plumb bob/spirit level in MWW normally used to monitor the jacking process to ensure equal mvmt.