What happened
On August 20, 2014, an L-13 Blaník glider, registration OK-4832, was conducting a training flight at the Plzeň Letkov aerodrome (LKPL). The flight, involving a student pilot and an instructor, was part of a syllabus exercise for landing in a restricted area. Due to the wind direction, the crew chose an approach path across the runway that resulted in a near-tailwind landing.
The aircraft touched down on the right edge of runway 26 at approximately 95 km/h with full braking and flaps extended. Following touchdown, the crew noted that the deceleration was insufficient. Both the student and the instructor applied the wheel brakes, but the aircraft continued to roll straight across the airfield. As the glider traveled approximately 192 meters along the landing area, it approached the edge of the airfield, where the terrain drops sharply.
Unable to stop the aircraft before reaching the boundary, the glider fell down a steep embankment, resulting in a nose-first impact with the ground. The impact caused significant structural damage to the nose section, the fuselage, and the right wing.
The investigation
The ÚZPLN investigation examined the flight maneuvers, the mechanical condition of the aircraft, and the environmental factors. The investigation established that the crew was properly qualified and the aircraft had a valid airworthiness certificate.
Technicians inspected the braking system and found no mechanical failure in the wheel brake operation. While the instructor noted a sensation similar to a broken brake cable when pulling the lever, the maintenance organization confirmed the brakes were functional. The investigation also reviewed the approach geometry, noting that the chosen approach angle relative to the wind resulted in the landing occurring with a tailwind component.
Findings
- The decision regarding the approach direction resulted in the glider landing with a tailwind component.
- The crew reacted too late to the extended landing roll.
- The instructor focused on applying the brakes but did not utilize the option to turn the glider by placing a wingtip on the ground to steer it away from the edge of the airfield.
- The aircraft's momentum and insufficient deceleration led it to the edge of the airfield boundary.