Jacking Restrictions
There are many restrictions to jacking for each type
aircraft If you violate any of these restrictions, there is
a good chance that you will have an accident, damage
the aircraft, or injure someone. The restrictions gen-
eral] y concern aircraft gross weight and configuration.
Some of the considerations are fuel dispersion in
fuselage and wing tanks, engines in or out, and tail hook
up or down.
Details on restrictions and procedures are in the
MIMs, and you must know them and follow them
exactly. If you don’t, you will be in trouble. Don’t forget
that many squadrons will have their own local standing
instructions for jacking aircraft, which contain
additional safety precautions and restrictions. You must
know them also.
JACKING PROCEDURES
The jacking procedures vary for each aircraft type
and its configuration. The procedures that follow are
examples of what you could encounter. Fairly exacting
steps are given to provide clarity. Remember these steps
are from representative type aircraft, and are not
necessarily accurate for all. When actually jacking
aircraft, you must follow the exact procedures described
in your MIMs.
The location of your aircratt will determine what
you need for equipment. Jacking procedures on a ship
require tiedown procedures to prevent aircraft from
shifting on jacks. When tiedown chains are to be used,
position them in accordance with the MIM, so as not to
interfere with the landing gear during the drop check of
the gear. Jacking procedures on land do not require
tiedowns, except in high-wind conditions.
Aboard ship, squadron maintenance controls will
request, through the carrier air group (CAG), permission
to place an aircraft on jacks. Check your MIM for
jacking restrictions, warnings, and cautions. Obtain the
support equipment required by the MIM, ensuring all
preoperational inspections have been completed. Make
sure that all protective covers and ground safety devices
are installed, as required by the MIM. The surrounding
area around the aircraft must be roped off during the
entire aircraft jacking operation, and signs posted stating
“DANGER: AIRCRAFT ON JACKS?’ The area
below and around the aircraft must be cleared of all
equipment not required for the jacking operation. Install
jack adapters, aircraft mooring adapters, and tiedown
chains as required by the MIM. Figure 3-29 shows an
Figure 3-29.—Carrier tiedowns for aircraft jacking.
example of carrier tiedown for aircraft jacking. Position
and extend wing and nose jacks until seated on wing jack
and tiedown adapters.
NOTE: Some aircraft require the extension of
the center screw to provide for clearance of the
gear doors.
Raising Aircraft
Apply jack pressure on each jack without lifting the
aircraft, and check to see that the base of each jack is
evenly seated. Correct base position of jack, as required,
for firm base seating. For shipboard operations, all jacks
must be tied down before jacking aircraft with a
minimum of three tiedown chains per jack. The jack
must be tied down at the spring-loaded wheel caster
mounts, thus allowing the jacks to make small move-
ments with the aircraft jack points. Release the aircraft
parking brake. Remove main landing gear chocks. Jack
aircraft evenly and extend tiedown chains while jacking.
Extension of tiedown chains must be coordinated in a
way that preload on each tiedown chain is partially
removed before jacking. Partial preload is maintained
with jacking of aircraft by rotation of the chain
tensioning grip.
3-42
