What happened
On August 23, 2014, at approximately 15:10 UTC, a HI-MAX ultralight aircraft, registration OK-BUR16, was performing a recreational flight at a very low altitude near the village of Racková. The aircraft was flying just above the treetops, traveling southeast from the direction of Horní Lapač. During the flight, the aircraft struck 22 kV overhead power lines. The impact caused the aircraft to drop steeply and crash into a field, where an immediate explosion and fire occurred.
The pilot was ejected from the cockpit during the impact. Emergency services arrived at the scene to find the aircraft completely destroyed by the collision and the subsequent fire. The pilot sustained fatal injuries due to polytrauma caused by high-intensity blunt force impact and died shortly after the crash. The collision also severed three high-voltage conductors.
The investigation
The ÚZPLN investigation relied on witness statements and an examination of the wreckage. Witnesses reported that the pilot had been in good spirits earlier that day, having visited a local airfield to socialize. The aircraft was observed flying at a steady altitude, appearing to be at roughly the same height as the power lines (which were approximately 9 meters above the ground at the site of the collision).
Investigators examined the remains of the engine, which was a Trabant motor. While the engine was heavily damaged by heat, there was no evidence of mechanical failure prior to the impact; the engine was likely running at flight power at the time of the crash. The investigation also noted that the aircraft's technical certificate had expired, and the pilot was not wearing a seatbelt at the time of the accident. The seatbelt buckles were found at the scene, but they were not fastened.
Findings
- The pilot was flying at a very low altitude near the terrain.
- The aircraft struck 22 kV power lines at an altitude of approximately 9 meters.
- The incorrect decision by the pilot to fly at such a low altitude led to the collision with the overhead wires.
- The aircraft was not in a valid state of airworthiness, as it lacked a valid technical certificate and valid liability insurance.
- The pilot was not wearing a seatbelt during the flight.
- Weather conditions were favorable, with good visibility and no significant turbulence, and therefore did not contribute to the accident.