transporter" trailer, you're in luck. If any other type
extension, you will feel the pumping pressure increase.
trailer, truck, or flatbed is used, you must have
Don't continue to pump or you may damage the internal
sufficient manpower available to safely get the jacks on
ram stops because there is no load on the jack.
and off the vehicle. Jacks are heavy and cumbersome to
Lower the ram and screw out the extension screw,
handle. Loading and unloading is hazardous even when
but don't forcibly overextend it past the internal stops.
you have enough people. Usually, a locally fabricated
Check to see that it is clean and oiled. If it is dirty, wipe
sling and some sort of hoist is necessary. Forklifts
it clean and coat it with a light film of MIL-L-7870 oil.
should never be used to handle or lift jacks. The tripod
On jacks equipped with wheels, check the wheels
cross braces are not strong enough, and you will
and springs suspension assemblies to make sure they
damage the jack. The chances of dropping it are also
are in good condition. Towing or dragging these jacks
around with broken wheels will damage the frame or
The wheels on a tripod jack are not made for towing
the jack. They are small, allow only a couple of inches
Since many leaks in jacks will only appear when
of clearance, and are spring loaded. Bouncing over
the jack is under a load, be sure to watch for leaks when
uneven surfaces will usually cause the jack footplates to
you are jacking the aircraft. If you find a leak, or other
hit the ground, and that can spin the jack around, tip it
defects, during the preoperational inspection, do not
over, or damage the tripod structure. Airframe jacks
continue to use the jack. Down or red line it, tag it as
don't have towbars, the wheels can't be locked in
bad, report it, and turn it into the SE division (AIMD)
position so they track, and there are no brakes. NEVER
for repairs. Don't leave a defective jack where someone
try to tow airframe jacks.
else may use it.
Free swiveling casters and no brakes also mean that
jacks can move by themselves if not properly secured.
HANDLING AND MOVEMENT
A loose, 900-pound tripod jack on a pitching hangar
deck could be disastrous. Jacks can also be moved by
Handling airframe jacks can be hazardous. The
jet or prop blast. Therefore, any jack that isn't tied down
jacks are heavy--anywhere from 110 to 900
can be a hazard. Since there are no tie-down rings on the
pounds--and the wheels are free swiveling and small.
jacks, you must take care as to how you attach the
Directional stability is poor, and pushing one into
tie-down chains or ropes to prevent damage to the jack.
position around an aircraft is no simple chore. Trying to
This is particularly true aboard ship where the jacks are
move or position a tripod jack by yourself is hazardous.
likely to be "working" against the tie-downs in rough
If the jack is dirty and covered with grease or fluid, it's
even more hazardous. The jack footplates and wheels at
the base of the tripod stick out, and are notorious
"foot-crunchers" and "shin-knockers." It's not hard to
damage an aircraft tire, wheel brake assembly,
The extension screws on jacks have a maximum
hydraulic lines, landing gear door, or any other part of
extension range. This range is stenciled on the jack. An
an aircraft if you are not careful and ram it with a jack.
internal stop prevents overextending the screw. If you
Movement of jacks aboard ship when there is any
forcibly overextend the screw, which isn't hard to do,
pitch or roll of the deck is extremely hazardous. Even
you not only damage the internal stop mechanism, but
with a calm sea, a smart turn into the wind by the ship
also make the jack unsafe and hazardous to use. An
while you're moving an airframe jack can be disastrous.
overextended screw is very likely to bend or break off
Movement of jacks from hangar to hangar, through
from any side motion.
hangar bays, and across hangar tracks and ramp seams
The extension screw on a jack is equipped with a
can easily damage a jack and put it out of
jack pad socket. The aircraft jack pad fits into this
commission--just when you need it!
socket and into a fitting or socket in the aircraft. The
Transportation of jacks over longer distances
sockets and pads are designed to take vertical loads but
ashore, such as from the SE pool to a hangar on the
not much horizontal pressure. The pads can shear or
other side of the field, can be a real problem. If your SE
slip from either the jack or aircraft socket if enough side
division (AIMD) has locally fabricated a special "jack
load is applied.