What happened
On July 10, 2001, a two-seat SZD-9-bis 1E Bocian glider was performing a training flight via aero-tow at Dessau. The flight, intended for PPL-C training, was occupied by an experienced flight instructor in the rear seat and a student pilot in the front seat.
After being towed to an altitude of approximately 450 meters and releasing from the tow plane, the glider performed several left-hand turns. Following the release, the aircraft proceeded in a southeasterly direction. Witnesses observed the glider flying with large angles of attack, followed by recoveries into normal flight. Approximately 400 meters from the takeoff point, the aircraft entered a spin. Witnesses noted two to three right-hand spin rotations. The glider then impacted the ground at an angle of approximately 60° to 70° without any visible attempt to recover from the upset. The impact resulted in two fatalities and the total destruction of the aircraft.
The investigation
The BFU investigation focused on the technical condition of the aircraft, the flight environment, and the physical condition of the crew. Technical examination of the SZD-9-bis 1E Bocian revealed no mechanical failures or control malfunctions; all observed damage was consistent with the ground impact. Weather conditions at the time were favorable, with a temperature of 20°C and light winds.
The investigation also examined the crew's medical status. While the student pilot had significant experience in powered aircraft, the flight instructor was highly experienced with over 1,300 glider flight hours. A post-mortem examination of the instructor revealed advanced cardiovascular disease, including significant arterial calcification and evidence of previous myocardial infarctions. Crucially, the autopsy identified a fresh, extensive transmural infarction of the left ventricle.
Findings
- The flight instructor suffered a fresh myocardial infarction during the flight, which likely caused a sudden loss of consciousness or physical incapacitation.
- The instructor's medical condition may have led to a physical blockage of the flight controls.
- Due to the tandem seating arrangement, the student pilot was unable to observe or assist the instructor during the medical event.
- Although the student pilot was capable of recovering from an upset, no recovery attempt was observed during the final spin.