Flight Operations
The pilot was conducting parachute operations, colloquially known as 'lifts'. On the day before the accident, he had performed 13 lifts, eleven to 12,000 ft and two to 5,500 ft or below. On the accident day, the first lift departed at 0927 hrs with nine parachutists, climbed to 12,000 ft, and landed at 0946 hrs. Three more flights followed, averaging 18 minutes each, with ground times of no more than 7 minutes. The last of these landed at 1100 hrs, after which the aircraft was refuelled with 230 liters of Jet A1 fuel.
Initially, all flights used Runway 29. As the wind freshened from the south, the pilot requested the shorter Runway 21. The air/ground radio operator refused because the pilot had not been checked out for that runway per the aerodrome manual. The pilot then approached a check pilot, who agreed to observe a flight. The check pilot briefed the pilot of OY-JRR on Runway 21 procedures, emphasizing an early abort decision if needed. The check pilot reported a thorough pre-takeoff check using the full checklist, and the subsequent flight was satisfactory.
Subsequent Flights and Accident
After the check flight, the aircraft took off again at 1148 hrs and flew five more flights, with intervals of 7 to 36 minutes. The check pilot observed several flights from Runway 21; most seemed normal, though on one occasion the climb gradient appeared shallower, attributed to decreased wind. The aircraft was refuelled again after landing at 1443 hrs, adding 266 liters. The next takeoff was at 1447 hrs, climbing to 12,000 ft, landing at 1521 hrs.
The accident occurred on the pilot's eleventh flight. Before it, the aircraft was refuelled with 100 liters at 1555 hrs. Shortly before 1605 hrs, the aircraft taxied to Runway 21. Acceleration seemed normal, but the tail never rose in the usual manner before becoming airborne. The jump-master noted the aircraft passing the refuelling installation and parked aircraft beyond the Runway 21/29 intersection, past the normal liftoff point. He heard the pilot shout "Abort". A parachutist yelled "Brace - Brace, everyone on the floor". The aircraft stopped abruptly when its left wing and cockpit struck a camouflaged F100 fighter parked as a museum exhibit left of the southern edge of Runway 21.
Aftermath
Cabin occupants vacated with mutual assistance. Aerodrome firefighters extinguished a small engine fire, and witnesses helped occupants move away. The pilot remained unconscious in the cockpit. Paramedics attended him, and he was taken to hospital, where he succumbed to his injuries.
Probable Cause (Official Findings)
The pilot's training was probably adequate for normal and abnormal circumstances envisaged by his instructor. However, he was not familiar with handling or performance characteristics during takeoff with flaps up, and may not have identified the wrong configuration. The design authority considered this configuration "outside the normal flight envelope" and produced no performance charts or procedures for its use. The investigation concluded that in such circumstances, it is essential for the pilot to follow published procedures and positively ensure correct takeoff configuration.