After some 23 years of development, the design of the Martin-Baker Ejection Seats was becoming somewhat complex, and towards the end of the 1960 decade a new design was put in hand which eventually became the Mark 9 seats. The general design features of the ejection gun and guide rail, the barostatic time-release unit, the drogue gun and the personal equipment connector were retained, but considerable changes were made to the general seat structure, the drogue container, the parachute and the seat pan. These design changes resulted in a marked improvement in the appearance of the seat and in personal comfort for the occupant. These seats were equipped with power retraction and a completely new gas-operated seat firing system, superseding firing cables and utilising one firing handle only, mounted on the seat pan, the face screen and its firing cable being dispensed with.
- Seat firing handle pulled
- Harness retraction operated
- Canopy jettison initiated
- Ejection gun fires, seat moves up guide rails, secondary cartridges fire
- Leg restraint cords tighten until the rivets shear
- As seat rises, static line initiates drogue gun time-delay
- As seat rises, static line initiates barostatic time-release unit
- Aircrew services and electrical lead disconnected
- Emergency oxygen turned on
- Underseat rocket pack initiated
- Approx 0.55 sec after ejection, drogue gun fires, 22 in. dia then 5 ft dia drogues deploy to stabilise and slow seat
- Above 5000 m (16000 ft)
- barostat prevents operation of time-release mechanism
- Below 5000 m (16000 ft), low speed
After delay of 2 secs to give time for speed to decrease, the barostatic time-release unit operates to -
- release parachute harness from seat locks
- release scissor shackle to release drogues and commence parachute deployment
- Main parachute deploys, aircrew separates from seat after being held momentarily by sticker straps. Action of sticker straps ensures divergence of aircrew and seat
- Operation of auxiliary parachute pulls parachute hard shell clear of area
- Normal parachute descent
- Manual lowering of personal survival pack
- Manual initiation of liferaft inflation (when carried)
- Manual separation system available if necessary. Operation of manual separation handle releases parachute harness, negative-g strap, PEC and leg restraint cords. Parachute withdrawal ine is severed, freeing parachute from seat. Aircrew can then use rip cord to operate parachute