What happened
On April 2, 2011, at approximately 15:25 UTC, an L-23 Super Blaník glider, registration OK-01216, was being towed from Medlánky Airport (LKCM) toward the Jinačovice area. During the climb, the pilot of the towing aircraft, a WT9 Dynamic, noticed the glider entering an unusual and dangerous attitude, with the nose pitching down at an angle of approximately 45 degrees.
Due to the immediate threat to the safety of the towing aircraft, the tow pilot decided to disconnect the cable. Following the release, the glider was observed descending rapidly and appearing to fly at a very low speed. The pilot of the glider was unable to respond to radio communications or instructions from the tow plane. The glider eventually entered a spin at low altitude, striking the ground near a wooded area. The impact resulted in the destruction of the aircraft and caused one serious injury to the pilot and one minor injury to the passenger.
The investigation
The ÚZPLN investigation examined the flight sequence, the technical condition of the aircraft, and the medical and professional status of the crew. Investigators found that the flight control systems of the L-23 Super Blaník were fully functional and that no mechanical failure had occurred. The tow cable remained intact and was still attached to the glider's tow hook at the time of the crash.
Regarding the crew, the investigation established that the pilot did not meet the required flight experience for carrying passengers, having completed only a 21-minute instructor flight on this type in the preceding 90 days. Furthermore, the investigation revealed that the pilot had intentionally misrepresented his medical history during a recent Class 2 medical certification renewal, concealing known health issues.
Findings
- The primary cause of the accident was a sudden deterioration in the pilot's health, which led to a loss of consciousness and rendered him unable to control the glider.
- The tow connection had to be severed to protect the towing aircraft from the glider's uncontrolled flight path.
- The pilot failed to meet the minimum flight experience requirements for carrying a passenger on this aircraft type.
- The pilot's medical fitness was compromised by his failure to disclose actual health conditions during his medical examination.