What happened
On August 11, 1998, a Bielsko-Biala glider was performing a winch launch for thermic flight near Jena-Schöngleina. The takeoff process proceeded normally from the initial tow until the aircraft lifted off the ground. Following takeoff, the aircraft entered a climb with an excessive angle of attack. The pilot did not correct this steep climb, and at an altitude of approximately 40 to 50 meters, the aircraft experienced a stall. The glider rolled over the left wing and, following further rotation around its longitudinal and vertical axes, impacted the ground nearly vertically in a slight tail-low attitude. The impact, which occurred about 100 meters from the launch site, resulted in the fatal injury of the pilot and the total destruction of the aircraft.
The investigation
An investigator from the BFU examined the site and reviewed witness statements. Weather conditions at the time were favorable, with a wind from 230°-240° at 8-12 knots and the runway facing 200° in operation. A technical inspection of the Bielsko-Biala revealed no mechanical defects in the control systems; all structural failures and broken control linkages were attributed to the forces of the impact. While the pilot held a valid license and sufficient experience, the investigation noted that the pilot's medical records contained disqualifying health history, despite having been previously certified as fit to fly. A forensic autopsy in Jena confirmed that the injuries were caused by the accident, though investigators could not definitively rule out or confirm that acute health issues impaired the pilot's reactions during the launch.
Findings
- The primary cause of the accident was the underspeed stall during the initial climb phase of the winch launch.
- The aircraft was flown at an excessive angle of attack immediately after liftoff.
- The altitude of 40-50 meters provided insufficient margin to recover from the stall once it occurred.
- A potential impairment of the pilot's reaction capabilities due to underlying health conditions could not be excluded.