What happened
On January 23, 2006, a Fire G 30/24 hot air balloon was conducting a scheduled flight as part of a balloon event. The flight originated in Inzell, with a brief intermediate landing performed to exchange passengers, the pilot, and one gas cylinder. After the second takeoff, the balloon traveled for approximately 75 minutes before approaching a landing site south of Ruhpolding.
During the final approach to the ground, the parachute line became entangled in the top of a tall coniferous tree. The pilot was unable to disentangle the line, which led to the unintended deflation of the balloon envelope. As the envelope lost its shape, the basket descended through the branches of a deciduous tree. The basket struck the snow-covered ground with significant force. During the descent, the pilot attempted to use the burner to slow the impact; however, the heat from the burner caused extensive damage to the lower section of the balloon envelope.
The investigation
The BFU investigation focused on the sequence of events leading to the entanglement and the subsequent descent. Investigators examined the aircraft, which was operating under Dutch registration, and reviewed flight path data recovered from an onboard satellite navigation device. The investigation also assessed the condition of the aircraft and the meteorological conditions at the time of the accident, which included a light wind of 4.5 knots and temperatures of -9°C.
Findings
- The primary cause of the accident was the entanglement of the parachute line in a tree during the landing approach.
- The entanglement triggered an uncontrolled deflation of the balloon envelope.
- The basket's descent was only minimally slowed by the branches of a deciduous tree before it hit the ground.
- The use of the burner in an attempt to mitigate the impact resulted in thermal damage to the balloon envelope.