Seat Sequencer LITEF

LISS

Developed for the ejector seat in the Eurofighter

System for controlling the escape sequence of an ejector seat

The LITEF LISS Seat Sequencer is a compact system designed with multiple redundancy and is used to control the escape sequence of an ejector seat rescue system. It was developed on behalf of Martin-Baker Aircraft specifically for the MK16A-ejector seat in the Eurofighter.

The seat sequencer is not activated until the pilot actuates the ejection mechanism. When the pilot leaves the cockpit, the recording of the current movement data by accelerometer and pitot sensors, as well as the barometric altitude, begins. Depending on these variables, an escape sequence with variable timing is initiated that initially deploys a pilot chute, then the main parachute. Finally, the pilot is separated from the seat.

The data from the sensors gets processed in independent CPUs and evaluated by a complex software and hardware voting process. This in turn leads to the coordinated activation of the pyrotechnical igniters located in the seat. The activation data are stored in the Seat Sequencer to enable them to be analysed at a later point in time.