What happened
On June 28, 2009, an Ikarus C 22 C Aero ultralight aircraft departed from the Greiz–Obergrochlitz landing field for a recreational flight. Shortly after takeoff, the pilot reported engine problems via radio and expressed an intention to return to the airfield. Witnesses observed black smoke emitting from the exhaust and noted an irregular engine rhythm.
While attempting a right-hand turn at an altitude of approximately 50 meters, the aircraft's left wing struck the lower branches of a tree located at the edge of the airfield. The impact caused the aircraft to crash into the ground, where the cockpit area was destroyed and the engine penetrated the soft earth. Both occupants sustained serious injuries.
The investigation
The BFU investigation focused on the mechanical state of the aircraft and the legality of its configuration. Investigators found that the aircraft's equipment and markings did not comply with the manufacturer's data sheet. Specifically, the aircraft was equipped with a BRS-UL 3 parachute system that was not approved for the C 22 C model according to the official specifications.
Furthermore, the investigation revealed discrepancies regarding the aircraft's weight and loading. The aircraft's empty weight was determined to be 255.2 kg, and with a payload of approximately 213 kg, the total weight exceeded the allowable limits. The investigation also noted that the pilot's license had expired on June 3, 2009, prior to the accident.
Findings
- The engine failure during the climb phase was the primary trigger for the emergency maneuver.
- Witnesses observed black smoke, suggesting an overly rich fuel mixture during the takeoff phase.
- The aircraft was in a non-compliant configuration, as the modification process did not follow the manufacturer's specific requirements.
- The total takeoff weight exceeded the maximum allowable limits due to contradictory weight and loading information in the aircraft's documentation.
- The pilot attempted an emergency turn at a low altitude, which led to the wing strike.