MK2 Ejection seat

Upgrading the Mk1 to automatic operation


Upgrading the Mk1 to automatic operation

First Mk2 ejection was on 15th July 1952

332 lives saved

Experience with the manually operated seats had shown that a number of fatalities had occurred, due to unconsciousness after ejection, inaction due to circumstantial stress, or lack of time to carry out the necessary manual operations when ejecting at low altitudes. Accordingly, effort was concentrated on producing a simple, yet effective, fully automatic ejection seat, capable of being produced in quantity, reliable in service, and designed to permit the retrospective conversion of most of the existing manually operated seats already installed in service aircraft.

In the design of the first automatic seat, it was decided to house the personal parachute in a container in the back of the seat and the dinghy pack in the seat pan, to facilitate the use of the drogue to effect deployment of the parachute. It was also necessary to devise some means of disconnecting the drogue from the seat at the correct time and transferring its pull to the parachute, and simultaneously a means of releasing the occupant complete with his parachute and dinghy pack from the seat.

On the Mk1 seats, the drogue had been attached to the top of the seat by a solid shackle. This was now replaced by a “Scissor Shackle”, capable of being opened automatically at a pre-determined time.

Aircraft fitted: Meteor, Supermarine Attacker, Westland Wyvern, Canberra, CF-100, Hawker Sea Hawk, Venom, Hawker Hunter, Hawker, Supermarine Swift, Saunders Roe
Operating ceiling Unknown
Minimum height/speed Unknown
Crew boarding mass range 70.4 to 101.7kg
Crew size range 5th to 95th percentile
Maximum speed for ejection 400+KIAS
Parachute type Irvin I 24
Parachute deployment Automatic
Drogue parachute type24 in. Later versions 22 in. Controller drogue and 5ft stabiliser drogue
Drogue deployment Drogue gun. Initiated by 1 sec clockwork time-delay, tripped by short static line harness type 1 to 4 ejection seat operation type
Ejection gunEjection gun; Early version – two cartridge, 60 ft/sec; Later versions – 50 ft/sec Later versions – 80 ft/sec
Ejection initiationFace screen firing
Barostatic time-release unitYes
Manual override handleNo, but provision for manual separation
TimersTime-release unit for man/seat separation
Seat adjustmentUp/Down
Arm restraintsNo
Leg restraintsIntegral thigh guards and foot rests
Oxygen supplyBottled oxygen
Personal survival packLiferaft pack
Aircrew servicesNo
Command ejectionNo

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