Abstract: An electronic sequencer for an aircraft ejection seat comprising a plurality of sensors for air-speed, temperature, air pressure and acceleration. These sensors provide, via interface circuitry, signals in digital electronic form to a microprocessor which, when appropriate, initiates various functions of the ejection seat, such as the deployment of drogue and main parachutes and release of seat harness. The sensors and main components of the microprocessor are provided in triplicate and the microprocessor uses a polling procedure to obtain a high level of reliability of operation.