What happened
On October 26, 2013, an ASW 15 glider, registration OK-7111, was performing a landing at Broumov airport. The pilot had been flying in wave conditions earlier in the day, reaching altitudes of approximately 2,222 meters. During the descent and approach to runway 14, the aircraft encountered intense mechanical turbulence.
While maneuvering through the circuit, the pilot increased the airspeed significantly, reaching 169 km/h, which far exceeded the recommended approach speed of 90–100 km/h. As the aircraft progressed toward the runway, the airspeed continued to climb, reaching 192 km/h with a high sink rate of -6.2 m/s. The glider struck the runway at a steep angle. The impact caused the main landing gear to bounce violently, leading to subsequent impacts that tore the tail surfaces from the fuselage, destroyed the cockpit, and caused the aircraft to flip onto its back.
The investigation
The ÚZPLN examined the flight data from a GNSS flight recorder, analyzed wreckage, and reviewed airfield camera footage. The investigation established that the aircraft was airworthy and the pilot was properly licensed. Investigators noted that the pilot's airspeed increased during the approach rather than decreasing. An AFIS controller witnessed the approach and attempted to instruct the pilot to extend the air brakes, but the pilot did not respond to the radio call. The pilot reported that the turbulence was so severe that he struck his head against the cockpit canopy, which may have impaired his ability to correct the flight path.
Findings
- The pilot incorrectly increased the airspeed while encountering intense mechanical turbulence.
- The pilot failed to extend the air brakes in a timely manner, leading to an excessive approach speed and a steep descent angle.
- The pilot's inability to manage the approach error was likely exacerbated by a head injury sustained during a heavy turbulence encounter.
- The severe impact and subsequent bounces caused the structural failure of the tail section and the destruction of the cockpit area.
- The pilot sustained serious injuries during the accident.