The exercise was supposed to look like an emergency without being one. Engine number one would be brought to idle just as the aircraft rotated; the trainee in the right seat would respond, hands quick, feet quicker, restoring control before the simulated failure became a real problem. The exercise had a target: the trainee was supposed to react in about a second and a half. On the morning of 17 March 1977, on runway 31 at Glasgow Prestwick, the trainee took two to three seconds. It was not a long delay. It was long enough.
The Boeing 707-436, registration G-APFK, had been flying since 1960 - first as a BOAC airliner, then with BEA Airtours, finally with British Airtours. Sixteen years of service had not made it new, but it was still a working jet, powered by four Rolls-Royce Conway 508 turbines that put a noticeable rumble through the airframe at full power. On board were four men. A 29-year-old first officer trainee was in the right seat, with the controls. A 48-year-old flight commander sat beside him, ready to inject the simulated failure. A captain trainee occupied the flight engineer's panel. And behind the commander, watching everything, sat a supervisory first officer. No flight number was issued. The session was internal: company training, company aircraft, company crew.
The wind was 18 knots with gusts forecast to 35 - lively but not unusual for a Scottish March. The tower passed the crosswind information; the commander relayed it to the trainee; the trainee applied full power and began the take-off roll. At VR, around 125 knots, the aircraft began to rotate off the runway. That was the moment the commander pulled back engine number one's thrust lever and said "engine number one's failed," then "I have it." Left rudder trim went in. The aircraft climbed - perhaps 20 feet, perhaps a little more. Then it began to come back down. The left wing dropped 20 degrees. The number one engine - the one that had been brought to idle, not actually broken - struck the left edge of runway 31. The aircraft yawed hard right, rolled, and engine number four hit the ground too.
What followed was not a controlled landing. The 707 slid sideways down the runway, the landing gear collapsing, all four engines tearing away from the wings under the force. Fire broke out immediately. The aircraft came to rest at the intersection of runways 31 and 3, a wreck that twelve minutes earlier had been an airworthy jet. And then the part of the story that always feels like luck or something larger: every one of the four men on board got out alive. One was injured during the evacuation. The other three were uninjured. They had walked into a controlled training exercise and walked out of a burning aircraft.
The Air Accidents Investigation Branch began work the next day. The cockpit voice recorder told a clean story: the simulation was textbook, the trainee's response was nearly textbook, but "nearly" was the problem. The probable cause, published in September 1978 after sixteen months of investigation, was clinical: "A loss of control which resulted from a delay in taking full corrective action during a simulated outboard engine failure exercise during take-off." G-APFK was damaged beyond repair and written off in November 1978. It was scrapped in 1979. The four crew kept flying. The exercise itself - simulated outboard engine failure on take-off - remained part of pilot training, refined slightly by what Prestwick had taught the industry.
There is no monument at the intersection where the aircraft stopped. Runways 31 and 3 still cross at the same angle. Training flights still operate out of Prestwick, though the aircraft are smaller and the procedures stricter. If you stand at the threshold of runway 31 today and look down its length, you are looking at a stretch of asphalt that came within a second and a half of being remembered very differently.
The accident site is at Glasgow Prestwick Airport (EGPK / PIK), 55.516 N, 4.613 W, at the intersection of runways 31 and 3 (now 30 and 03 after magnetic variation updates). Prestwick sits in flat coastal Ayrshire approximately 32 mi southwest of Glasgow, with the Firth of Clyde 2 nm to the west. From the air the airport is unmistakable: a long primary runway aligned roughly northwest-southeast, with the town of Prestwick on its western boundary. Glasgow International (EGPF) lies about 25 nm north.