Ejection Seat – Huge Forces Act on the Body
Activating an ejection seat triggers a force of over 12 G, which corresponds to twelve times the body weight. The forces of such magnitude may affect physical size by causing loss of height. Pilatus Aircraft Ltd
Ejection seats are designed to save a pilot’s life in an emergency, but they are not entirely without risk. Acceleration increases to 12 G within one to two seconds of triggering. Such tremendous forces ensure the parachute deploys before the pilot reaches the ground.
It is impossible to practise actually triggering an ejection seat. In an aircraft on the ground, the pilot would be catapulted up to 40 metres into the air. But mechanics take part in various courses organised by Pilatus supplier Martin Baker and are entirely familiar with the procedures. The Martin-Baker Aircraft Company is a pioneer and world market leader in the development and production of ejection seats. The “Ejection Seat General”, “Parachute” and “Emergency Pack” courses also take place in part at Pilatus in Stans.
In many situations, the pilot has very little time to decide whether or not to trigger the ejection seat. The ejection seat is activated by pulling firmly on a handle. The following steps are then performed automatically:
- Belts are tightened
- Primary cartridge is ignited
- Lock is released
- Various connections are cut (main oxygen, headset cable, electrical connection, anti-G suit, emergency oxygen)
- Canopy is released
- Rocket motor is ignited
- Barostatic unit is activated
- Drogue parachute is deployed
- Pilot is stabilised in seat
- Headbox is deployed
- Parachute is pulled out
- Empty box flies away with a separate auxiliary chute
- Pilot separates from seat and lands with emergency pack
The final completion work, including priming of the ejection seat, takes place at Pilatus over four days. At Pilatus, the following aircraft types are equipped with ejection seats:
- PC-7 MkII and PC-9 (MKK11A ejection seat) – is not primed until after installation in the aircraft as various connections and parts still have to be connected.
- PC-21 (MK16C ejection seat), which can be primed beforehand, leaving just three plugs to be connected during installation.
Quality Control Has Top Priority
Function and leak tests are performed during every quality check. Various adapters are fitted to simulate the functions using compressed air. Martin Baker seats all issued with certificates of conformity. In all these years, there has never been a single ejection seat malfunction.
Benedikt Kaiser, senior ejection seat engineer, has been with Pilatus for 45 years. He still finds it fascinating that the components work almost exclusively mechanically. Benedikt is affectionately known as “Ejection Beni” because he is a one-man operation. Ejection Beni has already equipped and fitted over 700 seats and carried out the same number of quality checks. “It never ceases to fascinate me that ejection seats are assembled with just under 500 parts”, says Benedikt with pride.