Tutor and Standard Cirrus collide during aerobatics in see-and-avoid airspace

The Tutor pilot and a cadet were fatally injured when a Grob G115E Tutor on an air-experience aerobatic sortie collided with a Standard Cirrus glider in uncontrolled airspace; the glider pilot parachuted safely, both aircraft destroyed. Visibility exceeded 25 km. The Tutor pulled up into a vertical manoeuvre; its left wing struck the glider's fin and the tail broke away. It probably entered a spin, recovered, then dived steeply to ground. A medical condition limited the Tutor pilot's look-out and probably incapacitated him on impact; both aircraft were on see-and-avoid in a high-traffic gap between controlled airspaces.

1. Aerobatic air-experience sortie: A powered trainer flew a cadet air-experience sortie that routinely included aerobatics while a glider flew a cross-country task, both in the airspace gap between two control zones.
2. Tutor pilot look-out restricted: The powered-aircraft pilot had a long-term medical condition that restricted his head mobility and limited his ability to maintain an effective look-out.
3. High-traffic gap, see-and-avoid only: Traffic in the corridor was very high and neither aircraft received a traffic service; the powered aircraft had no traffic-alert system and the glider's FLARM could not detect it.
4. Convergence unsighted by either pilot: The powered aircraft closed on a constant bearing, likely hidden behind its windscreen frame; the glider pilot sighted it below but could not avoid the collision despite evasive action.
5. Pull-up; left wing hits glider fin: After at least two aerobatic manoeuvres, the Tutor pitched up into a vertical manoeuvre. The outer section of its left wing struck the fin and right tailplane of the Standard Cirrus.
6. Glider tail breaks away: The glider's tail section separated and the glider became uncontrollable. The glider pilot opened his canopy and parachuted to safety.
7. Tutor spins, recovers, dives steeply: Though the collision damage did not prevent controlled flight, the aircraft probably spun, recovered, and entered a steep dive it did not pull out of; the cadet could not bail out in time.
8. Both in Tutor fatal; glider pilot bails: Both occupants of the powered aircraft were fatally injured in the non-survivable impact; the glider pilot parachuted to safety uninjured, and both aircraft were destroyed.