What happened
On June 10, 2017, an SF 34 glider, registration OK-3401, was performing a solo training flight at Liberec Airport (LKLB) when it experienced a series of bounces during landing on runway 34. The pilot, who was conducting a flight to practice thermal soaring, approached the runway at a speed higher than ideal for the conditions.
Upon touchdown, the aircraft bounced off the grass surface. In an attempt to correct the landing, the pilot applied the airbrakes, which caused the glider to float. While attempting to descend, the pilot simultaneously applied the brakes, leading to a subsequent touchdown and another bounce. The aircraft then underwent a final, significant bounce before dropping from a height of approximately 1 to 1.5 meters. The glider struck the ground heavily on its nose gear, causing the nose wheel to impact the runway and bringing the aircraft to a halt.
The investigation
The ÚZPLN investigation examined the flight sequence, the pilot's actions, and the mechanical state of the aircraft. The investigation established that the pilot was fully qualified and medically fit, and that the aircraft was airworthy, having undergone its annual inspection in July 2016. The investigation also reviewed the meteorological conditions, which were characterized by stable, partly cloudy skies with light winds.
Technical analysis focused on the structural damage sustained during the impact. The force of the nose gear hitting the ground caused the nose wheel assembly to strike the fuselage, resulting in the failure of the landing gear attachment structure and damage to the lower fuselage skin.
Findings
- The pilot approached the landing at an excessive speed.
- The pilot misjudged the flare height during the initial touchdown.
- The primary cause of the accident was the incorrect attempt to correct the initial bounce, which triggered a sequence of subsequent bounces and a final hard impact.
- The impact of the nose gear against the ground caused structural damage to the landing gear mounting points and the fuselage.