moving the trailer, particularly when loaded. The
or light load. Some stands have two hydraulic
forward hydraulic pump and release valve raise
reservoirs.
and lower the front end of the main frame. The
aft pump and release valve raise and lower the
Some stands have only two, instead of four,
wheel lift rams. The pumps on some stands are
rear end of the main frame. Operated together,
the pumps or release valves raise and lower the
located on top of the left side main frame, whereas
whole main frame at once.
some pumps are inside the main frame member.
The 4000A and 4000B trailers should never be
The lift linkage consists of four upper and four
used to transport engines, even for short distances.
lower links, centrally hinged in a jackknife
position. The linkage system is raised and lowered
by four frame lift rams. These lift rams are also
3110 Workstand
equipped with a ratchet and pawl system to pro-
vide a safe mechanical lock in case of a hydraulic
The model 3110 workstand is a 49-gauge
matching rail-type unit designed to mate with rail-
system leak or failure. Pawl knobs located on all
four upper links must be actuated and held to
type trailers for the roll transfer of the engine.
permit the rams to retract.
Model 3110, usually located in the hanger
or power plants work center, allows for the
The upper frame is attached to the lift linkage
horizontal maintenance and storage of aircraft
system and holds a cradle assembly at each end.
engines. These stands can be used on any hard
Inside each cradle are two rollers upon which the
surface, and are easily erected and maintained.
semicircular support tubes, holding the two
See figure 3-20.
parallel rails, can roll (rock from side to side). A
rotation adjustment knob, located on the left side
of the forward support tube, permits 10 degrees
SPECIAL-PURPOSE
of roll adjustment of the rails. Two traverse
SUPPORT EQUIPMENT
adjustment knobs, located on the left side of each
cradle assembly, permit 3 inches of horizontal
The Aviation Machinist's Mate has a require-
lateral (side) movement of the rails. Yaw adjust-
ment to use special support equipment to
ments up to 2.25 degrees left or right of the
accomplish tasks such as engine removal and
center line of the rails can be made using just one
corrosion control purposes. The aero bomb hoist
of the traverse adjustment knobs, or both in
and the jet engine corrosion control carts are
different directions.
examples of this special-purpose gear.
A mechanical winch assembly with a hand
crank is provided on the unit for moving an engine
Aero Bomb Hoists
onto the trailer when the rails are tilted. The ends
Aero bomb hoists are used in conjunction with
of the two upper rails are equipped with male and
female quick-disconnect couplings to permit
the air logistic trailer for aircraft engine removal
mating and load transfer from one type of stand
to another. Roller adapter assemblies are provided
on the rails to hold the engine. The roller adapters
can be locked in any position on the rail to center
the load. The very ends of the rails are equipped
with spring-loaded stop pins to prevent an engine,
on unlocked roller adapters, from accidentally
rolling off the rails.
The model 4000A stand has been in service for
many years. During that time many modifications
and changes have resulted in various configura-
tions of stands in the fleet. The U.S. Air Force
also uses this stand. Some stands have pneumatic
tires, and some have solid rubber tires. Some
Figure 3-20.-Model 3110 workstand assembly.
hydraulic pumps have selector collars for heavy
3-17
