What happened
On August 16, 2006, an ASW 1s9 B glider, registration OK-6601, was participating in the 2006 Czech National Gliding Championships at Staré Město airport. The aircraft had departed at 11:54 UTC for a competitive task involving a three-sector course with an expected duration of 2.5 hours.
Data retrieved from the aircraft's GPS unit indicates that the flight proceeded normally until approximately 15 minutes before the accident. During this final phase, the pilot began losing altitude, dropping below 150 meters above the ground. In an attempt to locate rising air currents, the pilot frequently changed direction while flying at a very low altitude. Ultimately, the glider's wing struck the treetops at the edge of a forest between the villages of Útěchov and Dlouhá Loučka, leading to a loss of airspeed and a fatal impact with the ground. The pilot, a 48-year-old experienced instructor, was killed in the crash.
The investigation
The ÚZPLN investigation examined the flight data from the onboard GPS, the meteorological conditions, and the pilot's credentials. The investigation established that the pilot held valid glider pilot licenses and medical certification. The aircraft was also found to be in a fully airworthy condition, with all required inspections and insurance up to date. Meteorological analysis showed stable conditions with light thermal turbulence and good visibility, which were suitable for the flight task.
Findings
- The pilot failed to maintain the minimum required flight altitude of 150 meters above the ground.
- The pilot likely made a delayed decision to perform an emergency landing in a pre-selected, suitable field.
- The impact with treetops caused significant structural damage to the fuselage and both wings, resulting in the total destruction of the aircraft.