What happened
On April 5, 2008, at approximately 12:00 UTC, a single-seat SU-1 ultralight departed from the LKMIRA public airfield in Miroslav. Shortly after takeoff, at an altitude of approximately 20 meters and roughly two-thirds of the way down the runway, witnesses observed the engine running irregularly.
In an attempt to return to the takeoff site for an emergency landing, the pilot executed a left turn of 10 to 15 degrees, followed by a right bank with an attitude of approximately 45 degrees. During this maneuver, the aircraft's bank angle increased to 90 degrees. The aircraft then entered an inverted position, falling into a descent that resulted in a ground impact at an angle of approximately 30 degrees. Approximately two seconds after the impact, the aircraft caught fire. The pilot sustained fatal injuries.
The investigation
The ÚZPLN investigation established that the aircraft was a unique, single-prototype construction. The investigation revealed that the aircraft had not been officially entered into the ultralight aircraft register, and no technical certificate had been issued by the LAA ČR. Furthermore, the aircraft's maximum takeoff mass (MTOM) exceeded the 300 kg limit established by LAA ČR regulations, as the empty weight was determined to be 265 kg.
Investigators examined the wreckage, which was spread over approximately 10 square meters. While the control cables and linkages remained intact, the engine mounts were deformed, and the engine was displaced by approximately 35 degrees. The fire, which originated in the cockpit area, destroyed the fuel, electrical, and cooling systems. The investigation also noted that the registration mark previously used by the owner was being used without authorization.
Findings
- The engine experienced a loss of power shortly after takeoff.
- The pilot attempted an emergency landing but failed to maintain control during the maneuver.
- The aircraft was operated without being properly flight-tested or certified by an authorized inspector.
- The aircraft's weight configuration exceeded regulatory limits for its category.