Ejection seat

Last modified: 5 Oct. 2010

Martin Baker Mk-10L

The AMX fighter is equipped with the Mk10L ejection seat, a lightweight version of the original Mk10 series, developed by Martin Baker and license-built by the italian Sicamb. The overall size footprint and weight of the Mk10L have been tailored to suit a large number of aircraft installations without giving up the excellent qualities in terms of performance and effectiveness of the original Mk10. Over 500 test ejections have been completed making the Mk10L one of the most tested and qualified seat world-wide.
The Mk10L is currently fully qualified and approved for installation in the following aircraft:

  • AMD Mirage
  • BAe Hawk
  • CASA C-101
  • Chengdu F-7
  • Embraer/Shorts Tucano
  • IAI LAvi
  • IAR Jurom
  • IAR 99
  • MB-339
  • Nanchang A-5
  • Nanchang F-5
  • Nanchang K-8/L-8
  • Saab JAS39
  • SIAI Marchetti S211
  • Soko Super Galeb

Unit construction

The Mk10L is designed in four main units:

  1. catapult
  2. main beam structure
  3. seat bucket
  4. parachute assembly

Parachute assembly and seat bucket can be removed or installed in the main structure inside the aircraft without having to remove the whole seat: this greatly simplifies and speeds up maintenance or cockpit access.[top]


When designing the Mk. 10 seat, a study was made of some 4,000 emergency ejections. It was found that the vast majority of critical ejections occurred with the aircraft descending rapidly close to the ground and banked less than 70 degrees. Very few inverted ejections were noted and those which did occur were above 500 feet or at a low altitude, descending, outside the capabilities of any escape system It was therefore apparent that, by improving ejection capability in the area in which most critical ejections occur, a greater improvement in life saving capability could be achieved than than by catering for the theoretical conditions required by some specifications. The 10L seat has been designed to these requirements and has an outstanding performance especially under high sink rate conditions at low altitude. The system is effective, simple and above all highly reliable.[top]

Low altitude operations

Ejection is initiated by operation of the seat firing handle situated on the front of the seat bucket between the pilot's legs. This results in the firing of a cartridge which sends a signal to the catapult and the harness retraction unit initiator.
Full retraction of the pilot's shoulders occurs within 0.2 seconds even under 2g deceleration. As the seat moves out of the aircraft on the catapult, the drogue gun and time release mechanism delays are activated, the pilot's services automatically disconnect, his legs and arms are restrained and the emergency oxygen is activated.

As the seat reaches the end of catapult stroke, the rocket motor ignites producing 4,500 pounds thrust for 0.2 seconds. Asymmetric thrust is built into the motor to ensure that the drogues are streamed clear of the seat and to increase spatial separation between seats in a multi-place aircraft. The total propulsion phase lasts 0.45 seconds. At 0.5 seconds the drogue gun delay expires, the drogue gun fires and the drogue parachutes are deployed.
The drogues stabilise the ejection seat and align it for parachute deployment. One second after drogue deployment the time release fires, releasing the drogues from the seat to deploy the personnel parachute. The connections between the seat and occupant are also disconnected, although the seat remains attached to the occupant by spring loaded clips. As the parachute fully inflates, the spring clips release and the seat falls clear, in this way seat/occupant collision is prevented. As the seat separates, the automatic liferaft inflation unit is armed, the automatic survival kit Deployment Unit Delay is initiated, the Personnel Locator Beacon is activated and the Life Saving Jacket Automatic Inflation Unit is armed. Four seconds after seat/occupant separation, the survival kit is automatically lowered to the end of its 4 metre (13 feet) lanyard. If the pilot wishes, the parachute can be steered utilising the built in steering lines.

On splashdown the survival kit is automatically opened and the liferaft and lifejacket automatically inflate. The parachute is immediately collapsed by water deflation pockets. The pilot boards the liferaft and awaits rescue utilising the signalling aids and provided survival equipment.[top]