What happened
On October 4, 2005, a Fire Balloons G 30/24 hot air balloon, registration HB-QHK, was participating in the International Alpine Hot Air Balloon Week in Flims. Following a period of unstable weather and shifting winds, the pilot attempted to land at the Rossboden military training ground near Chur.
During the approach, the pilot encountered unexpected earthen embankments at low altitude. To manage the descent, the pilot delegated the operation of the parachute valve to a passenger. This decision led to a sequence of violent impacts. The basket first struck an embankment, causing one passenger to nearly fall out. A second impact was much more severe, ejecting the second passenger from the basket entirely. A third impact resulted in the pilot being thrown from the basket and dragged approximately 20 meters along the ground. The remaining passenger eventually managed to stabilize and deflate the balloon.
The investigation
SUST examined the flight path, meteorological conditions, and the crew's decision-making process. The investigation established that the pilot had encountered difficult wind conditions, including turbulence and gusts up to 20 km/h, which had already forced two previous aborted landing attempts.
Investigators also looked into the status of the landing site. While the crew believed the military training ground was inactive, a misunderstanding regarding the specific activity schedule (KOSIF) meant that military operations were technically scheduled for that timeframe, though they were halted once the balloon became visible. The investigation also noted that the pilot had sufficient fuel reserves to continue searching for a more suitable landing site elsewhere in the Rhine Valley.
Findings
- The primary cause of the accident was the loss of control following inadequate flight tactics.
- The pilot failed to follow manufacturer recommendations regarding precautions for difficult landings.
- The pilot's decision to delegate the parachute valve operation to a passenger prevented the crew from maintaining proper control during the impact.
- The pilot failed to perform recommended burner shutdown procedures during the emergency landing.
- The pilot underestimated the height and scale of the earthen embankments at the landing site.
- Wind conditions at the time of the accident included gusts of up to 20 km/h.