PHYSICAL DESCRIPTION

controlled by the electronic sequencer, which uses altitude and airspeed information to select the correct mode of operation. PHYSICAL DESCRIPTION Each ejection seat, as installed in the aircraft, consists of five main assemblies. Each assembly is briefly described in the following paragraphs: (See figure 5-2.) 1. The catapult assembly is the means by which the ejection seat is secured to the aircraft structure during normal flight, and provides the initial force necessary to eject the seat from the aircraft during emergency conditions. The catapult assembly includes the barrel, ballistic latches, the piston, and the catapult manifold valve. 2. The main beams assembly includes the top and bottom crossbeams, top latch assembly, shoulder harness control handle, parachute deployment rocket motor, electronic sequencer, barostatic release unit, drogue deployment catapult, two multipurpose initiators, time-delay mechanism, two pitot assemblies, two ballistic manifolds, and two thermal batteries. 3. The seat bucket assembly includes the underseat rocket motor, lateral thrust motor, ejection control handle, safe/armed handle, leg restraint snubbers, emergency restraint release handle, shoulder harness control lever, seat height actuator switch, pin puller, and lower harness release mechanism. 4. The parachute assembly includes the parachute container and parachute canopy and drogue. 5. The seat survival kit assembly includes the lid assembly, emergency oxygen system, radio locator beacon, and rucksack assembly. Catapult Assembly The catapult assembly (figs. 5-3 and 5-4) secures the ejection seat to the aircraft structure Figure 5-2.-Forward ejection seat main assemblies. 5-4