What happened
On May 4, 2006, two hot air balloons prepared for a joint flight at a parkland site southeast of Bergisch Gladbach. Following pre-flight preparations and passenger boarding, the first balloon departed without incident. Approximately 20 seconds later, a second Thunder & Colt/AX10-210 balloon, carrying nine passengers, commenced its takeoff.
As the balloon progressed along its flight path, the envelope made contact with tree branches. This impact caused a large tear, spanning more than ten panels along the equator of the envelope. Despite intensive use of the burner to maintain lift, the basket became entangled in the canopy of a subsequent tree. The suspension lines and burner frame became caught in the branches, leaving the basket suspended at a 45-degree angle approximately 8 meters above the ground. Emergency responders arrived at the scene and successfully rescued the pilot and all passengers from the basket. Two passengers sustained light injuries during the incident.
The investigation
The BFU examined the flight conditions and the aircraft's technical status. At the time of the accident, weather conditions were suitable for visual flight rules, with light winds of 3 knots from the southeast. The takeoff site, located in a castle park at an elevation of approximately 380 feet MSL, was surrounded by trees roughly 20 meters in height. The investigation established that the distance from the takeoff point to the first obstacles in the direction of travel was approximately 46 meters. Given the envelope diameter of roughly 20 meters, the basket reached the tree line after traveling only about 36 meters.
Findings
- The primary cause of the accident was the collision between the balloon envelope and tree branches shortly after takeoff.
- The impact occurred because the distance traveled before encountering obstacles was insufficient relative to the balloon's dimensions.
- The intense use of the burner during the incident caused additional damage to the lower portion of the envelope, affecting approximately 15 panels.