What happened
On September 28, 2009, at approximately 09:27 UTC, a Kolibřík KK-1 ultralight aircraft, registration OK-DUT 02, departed from runway 09 at České Budějovice Airport. Following a takeoff roll and a stepped climb, the pilot initiated a right-hand turn at an altitude of approximately 20 to 50 meters with a bank angle of 5 to 10 degrees, heading toward 180 degrees.
Shortly after this maneuver, the aircraft experienced a sudden loss of control, banking steeply to the right. The aircraft entered a near-vertical descent at a heading of approximately 360 degrees, impacting the ground roughly 800 meters east of the runway threshold. The pilot sustained fatal injuries due to blunt force trauma from impacting the forward structure of the cockpit and passed away during transport to a local hospital. The aircraft was destroyed upon impact.
The investigation
The ÚZPLN investigation examined the wreckage, the engine, and the circumstances surrounding the flight. The engine, a Rotax 503, was found to have been operational at the time of impact, with no evidence of failures in the ignition, lubrication, or cooling systems. The propeller was also in operation during the crash, with damage to the blades likely caused by contact with the wing structure during the impact.
Investigators also reviewed the pilot's records and the aircraft's maintenance status. It was noted that the pilot's medical certificate was invalid, and the aircraft's technical certificate was also expired. However, toxicological analysis confirmed the pilot was not under the influence of alcohol, and no significant medical issues were identified that would have contributed to the accident. The investigation could not definitively prove or rule out a technical malfunction of the aircraft.