What happened
On June 12, 2021, a Breezer B400-6 ultralight aircraft departed from the Montabaur glider airfield for a local sightseeing flight. The aircraft was carrying a pilot and one passenger. Shortly after takeoff from runway 23, the pilot initiated a left-hand turn at a very low altitude.
As the flight progressed, the aircraft entered a climb, but the pilot subsequently increased the bank angle significantly. The aircraft's nose eventually dropped below the horizon, leading to a loss of altitude. Approximately 21 seconds after takeoff, the aircraft collided with a wooded area adjacent to the airfield at a low airspeed and caught fire. The pilot sustained fatal injuries, while the passenger escaped the wreckage with serious injuries.
The investigation
The BFU investigation reconstructed the flight path using video footage from a witness and various eyewitness accounts. The investigation examined the aircraft's technical condition, the pilot's experience, and the meteorological conditions at the time of the accident.
Investigators found no evidence of technical failure in the Breezer B400-6. The aircraft's weight and balance were within permissible limits, and the engine components, including the spark plugs, showed no signs of malfunction. The investigation also focused on the pilot's background, noting his extensive experience as a helicopter pilot and his recent flight activity at the Montabaur airfield. Meteorological data confirmed the presence of strong, gusty winds from the northwest, which were near the aircraft's operational limits.
Findings
- The primary cause of the accident was that the performance limits of the ultral-light aircraft were exceeded during a high-bank turn, leading to a collision with the terrain.
- The pilot initiated a turn before reaching a safe altitude, deviating from the published departure procedure.
- A strong tailwind created an optical illusion, likely causing the pilot to overestimate the aircraft's true airspeed.
- The aircraft was operating in turbulent conditions with winds near its operational limits.
- The pilot's extensive experience in helicopters may have contributed to a misjudgment of the aerodynamic risks, such as the danger of a stall at low airspeed during a high-bank maneuver.