What happened
On May 30, 2011, a student pilot was conducting a solo navigation training flight in a Tecnam P 92 - JS, registration OK-VOR, as part of a PPL(A) training syllabus. The flight plan included several planned landings, including at Zbraslavice airport (LKZB).
Upon approaching Zbraslavice, the pilot found that the ground station was not responding to transmissions. After evaluating the wind conditions, the pilot decided to enter a right-hand pattern for runway 33. During the approach, the pilot performed a missed approach after realizing the aircraft was too high over the threshold. On the subsequent attempt, an improper landing calculation resulted in the aircraft being too low at the threshold, forcing the pilot to apply power to stretch the glide to the runway.
After landing on the first third of runway 33 with several light bounces, the pilot applied intense braking. While focused on maintaining the aircraft on the runway centerline, the pilot failed to notice that the engine power had increased. The aircraft continued along the runway, crossed the taxiway, and traveled through a grassy area, eventually striking a roadside ditch and an embankment. The aircraft came to a stop approximately 850 meters from the runway, near a road leading to Štipoklasy.
The investigation
The ÚZPLN investigation examined the pilot's training progress, the aircraft's mechanical condition, and the environmental factors at the time of the accident. The investigation confirmed that the pilot was medically fit and sufficiently skilled to perform solo flights. The aircraft was found to be airworthy, and a subsequent inspection by an authorized service center confirmed that the braking and throttle systems were functional and that the engine had been forced to stop due to the impact with the ground.
Investigators also analyzed the landing performance and the possibility of unintended engine behavior. It was noted that the pilot's focus on directional control and braking prevented the immediate recognition of the power increase. The investigation also considered the impact of the runway slope and the possibility of an incomplete throttle reduction or an improperly set throttle lock.
Findings
- The primary cause was the loss of control during ground operations due to the pilot's momentary inability to recognize why the aircraft was not decelerating despite intense braking.
- An unintended increase in engine power likely occurred, potentially due to an incomplete reduction of the throttle or an improperly set throttle lock.
- The choice of runway 33 was suboptimal due to the wind direction and the runway's downward gradient.
- The aircraft sustained damage including a broken nose gear, a broken right main gear, and damage to the propeller and engine cowling.