catapult breech V-grooves when the seat is installed in
and bottom seat bucket slippers. The slippers provide
the aircraft.
smooth movement of the seat bucket and have threaded
studs to attach the seat bucket to the main beam.
Bottom Cross-Beam
Friction pads in the studs restrict lateral movement of
the seat bucket. Drogue bridle retaining channels are
The bottom cross-beam is machined from solid
secured to the rear of both main beams. Locating pins
light alloy and retains the main beams at the bottom
for the parachute container hooked brackets are bolted
end. Incorporated into the cross-beam is a gas passage
to the upper outside face of each main beam.
that forms part of the drogue bridle release system.
Interference blocks on the RH beam (forward seat) or
LH beam (aft seat) correspond with interference
Top Latch Assembly
devices on the catapult and the seat bucket to ensure
that only the correct assemblies are installed in forward
The top latch assembly fitted to the LH main beam
and aft cockpits (fig. 2-5).
secures the seat structure to the catapult. The assembly
consists of a housing with a spring-loaded latch
Top Cross-Beam
plunger, one end of which is shaped to engage the
catapult piston. The plunger may be withdrawn using
The top cross-beam receives and positions the top
the top latch withdrawal tool (handwheel). Passing
of the catapult and takes the full thrust of the catapult
through the center of the latch plunger is a
during ejection. Incorporated into the cross-beam is the
spring-loaded indicator plunger. When the ejection seat
upper drogue bridle release unit, which attaches the
is fitted to the catapult and the handwheel is removed,
upper leg of the drogue bridle to the seat. The studs
the latch plunger passes through the top cross-beam and
securing the RH main beam to the top cross-beam also
engages with the barrel latch. The shaped end of the
retain the RH parachute container mounting bracket.
plunger protrudes still further to engage the groove of
Two of the studs securing the LH main beam to the top
the catapult piston. Operation of the top latch is shown
cross-beam also retain the top latch assembly. A dowel
in figure 2-7.
in the top cross-beam is positioned in one of the
Figure 2-7.--Operation of the top latch assembly.
2-7
