What happened
On September 23, 2009, a private cross-country flight was underway from Hahnweide to Leutkirch-Unterzeil. At approximately 13:35 local time, the pilot was flying a MBB/BO 209 RV Monsun at an altitude of roughly 2,800 ft AMSL, passing over the airfield from north to south. The pilot intended to enter the south pattern for a landing on runway 06. Prior to the approach, the pilot had received information from the airfield controller regarding wind conditions, landing direction, and local traffic.
During the maneuver, the pilot attempted to execute a loop to better observe parachutists in the area before committing to the final approach. According to a witness, the aircraft performed a steep left turn that transitioned into a severe right bank and a nose-down attitude, described as a "knife-edge" maneuver. The pilot stated that the turn was likely too steep or performed at too low a speed. In an attempt to recover from the resulting roll and loss of altitude, the pilot applied full power and pushed the nose down, but the aircraft struck the ground.
The investigation
The BFU investigation examined the flight path, the aircraft's condition, and the pilot's actions. The investigation established that the aircraft first impacted the ground with the left wing and left main landing gear at a slight angle. This was followed by the impact of the engine, propeller, and fuselage. The wreckage showed significant deformation to the engine and cabin areas, and the left wing was destroyed. The investigation also reviewed the pilot's experience, noting a total of 649 hours on powered aircraft and approximately 309 hours on the specific model involved.
Findings
- The pilot attempted a complex maneuvering sequence (a loop) to visually check for parachutists in the vicinity.
- The maneuver resulted in an excessively steep bank angle and a loss of altitude.
- The aircraft entered a state of uncontrolled descent following the attempt to recover from the roll.
- The pilot sustained one serious injury during the impact.
- The aircraft was destroyed, though no fire occurred at the crash site.