The decision to develop the Mk.15 seat followed research carried out among military operators of the Pilatus PC7. This showed that while they were satisfied with the aircraft’s performance in its role of trainer, many would have liked the extra safety and reassurance of a high quality ejection system.
With the addition of ejection seats, the PC7 gains a greater degree of similarity with operational aircraft and student can receive early instruction on the disciplines necessary for working with this type of safety device.
- Seat firing handle pulled causing seat initiation cartridge to fire
- Seat pan front cross beam latches release, PSP drop down panel lowered to allow aircrew’s legs to assume correct position for ejection
- Harness retraction unit operated
- Negative-g strap released
- Primary cartridge fires
- Canopy fragmentation bullet fires
- Top latches disengage, seat rises up rails
- Drogue gun time-delay mechanism initiated
- Barostatic time-release unit (BTRU) initiated
- Emergency oxygen supplied to aircrew
- Drogue deploys to stabilise and decreases velocity of seat
- Barostatic time release unit monitors the altitude
- Above pre-determined altitude -
- Seat falls, stabilised by drogue
- Emergency oxygen supply continues
- Below pre-determined altitude -
- BTRU mechanism operates, cartridge fires
(If BTRU fails manual deployment also available by pulling manual
override handle)
- Harness reel strap and parachute canopy withdrawal line released
- Drogue gun cartridge fires to deploy drogue
- Lower harness locks released
- Drogue extracts and deploys the main parachute canopy
- Main parachute canopy fully deploys and lifts aircrew and personal survival pack (PSP) from seat
- PSP manually lowered on drop line below aircrew
- Normal parachute descent follows
- Manual opening of PSP
- Manual initiation of liferaft inflation (if carried)