What happened
On December 31, 2018, an L-13 SE Vivat motor glider, registration OK-6110, was performing a landing circuit at Tábor airport (LKTA) when the engine failed. The failure occurred after the pilot retarded the throttle to idle during the third turn of the circuit. Despite attempts to restart the engine, it remained non-operational, and the pilot continued the approach for a single-engine landing.
During the final approach, the pilot attempted to manage the braking flaps by reaching with the left hand to the flap control while keeping the right hand on the control stick. This movement caused a loss of attention to the aircraft's airspeed. Consequently, the airspeed dropped below the stall threshold, causing the glider to enter a steep descent. Due to the low altitude, the pilot was unable to recover the aircraft before it struck the ground on runway 34.
The impact was severe, causing the aircraft to bounce approximately 4 meters before settling. The force of the landing caused the main landing gear to intrude into the fuselage. The pilot sustained a serious injury consisting of a fractured right forearm caused by the movement of the landing gear control lever.
The investigation
The ÚZPLN investigation examined the pilot's actions, the aircraft's technical condition, and the sequence of events leading to the impact. The investigation established that the pilot was properly licensed and medically fit, and the aircraft was airworthy with all documentation in order. The investigation also reviewed the engine failure, noting that such an engine cutout can occur when the throttle is abruptly moved to idle in this aircraft type.
Findings
- The engine failed following the reduction of power to idle during the third turn of the circuit.
- Pilot inattention during the final approach led to a loss of airspeed.
- The loss of airspeed triggered a transition into a steep descent that could not be corrected at the low altitude maintained.
- The heavy impact caused significant structural damage to the L-13 SE Vivat, rendering it a total loss.