It probably is best not to fiddle with switches or controls when riding in the back seat of an air force plane.

A man who failed to obey that principle found himself hurtling out of the cockpit, smashing through the Perspex canopy and into space after grabbing the black- and yellow-striped handle between his legs. He had inadvertently pulled the eject lever and found himself blasted 100 metres into the sky on his rocket-powered seat.

The South African air force has confirmed the incident that took place last Wednesday, when the passenger took off for a flight with an experienced pilot from South Africa's Silver Falcons air display team. Investigators are assuming that the passenger tried to steady himself while the pilot was putting the Pilatus PC-7 Mk II through its paces by grabbing the eject lever.

"Much of the information has yet to be tested, but it is confirmed that a civilian passenger unintentionally ejected from a Silver Falcons Pilatus PC-7 Mk II Astra during a general flying sortie out of Langebaanweg air force base this week," a South African air force spokesman said. "The passenger was recovered [by helicopter] unharmed, and returned to Langebaanweg. The aircraft landed safely."

The spokesman said the flight had been cleared and all procedures adhered to "prior to the passenger boarding the aircraft", making it unlikely charges would follow.

A retired SAAF instructor pilot said the passenger was extremely lucky to have survived the ejection with barely a scratch.

"We train for this and if you don't get it right, and are not in the correct ejection posture, you can sustain severe spinal cord injuries or even worse," he told South Africa's Sunday Times.

He discounted the possibility that the seat fired of its own accord, as too many safety features were built into the system.

"All it takes is for the firing handle [the rubbery black- and yellow-striped loop] to be pulled up about 2.5cm and you're on your way out."

He said the ejection would have been dramatic. "You get one almighty kick under the backside and then you're gone. The seat separates from the pilot automatically and the chute opens," he said. "This is in case the pilot is incapacitated during the ejection."

Passengers would have been briefed on the ejection sequence and warned that the "loop" between his legs was not to be touched unless the pilot called "Eject, eject, eject" during the flight. Such a briefing is done routinely, even when two qualified pilots are involved in the flight. It is likely the rear cockpit was extensively damaged by the firing of the cartridges and rockets during the ejection.

The Silver Falcons are the SAAF's aerobatic team that perform precision formation and aerobatics displays at airshows around the country. The five pilots are all serving instructors at Central Flying School, Langebaanweg.

As one observer said: "What a trip. That guy took off in an Astra, came down in a parachute, and landed back at base in a helicopter. Not bad for a for a single flip."