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.

 Specifications

 How it works

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