What happened
On August 16, 2018, a commercial hot air balloon flight, carrying a pilot and four passengers, was conducting filming operations for a movie crew. After ascending to approximately 3,300 meters to utilize predicted winds, the pilot encountered unexpected windless conditions at higher altitudes, deviating from the original flight plan. Consequently, the pilot decided to descend over the Heerbrugg area to land between Heerbrugg and Au.
During the landing phase, the pilot attempted to fly at a low altitude of approximately 10 meters above the ground to reduce speed and navigate a meadow occupied by the Circus Royal. As the Z-180 Cameron Balloons Ltd balloon approached the far end of the landing site, it encountered an unexpected gust of wind. Despite the pilot applying maximum burner power to counteract the sudden loss of altitude, the basket collided with a circus truck and its trailer, which stood 4.50 meters high. The impact caused the basket to become wedged between the truck and the trailer at roughly one meter above the ground. The pilot subsequently activated the rapid deflation valve to settle the envelope.
The investigation
The investigation examined the pilot's decision-making regarding the landing site and altitude. It was established that the pilot chose a lower approach altitude to manage the limited length of the available landing strip. The investigation also reviewed the meteorological conditions, noting that while the pilot had sufficient fuel to reach an alternative landing site, the sudden wind gust was unpredictable.
Findings
- The collision was caused by an unpredictable wind gust that dropped the balloon's altitude below the height of the obstacle.
- The pilot's decision to fly at a low altitude to reduce speed decreased the vertical clearance over obstacles.
- There was sufficient fuel available to divert to a safer, alternative landing location.
- The collision resulted in one minor injury to a passenger and damage to both the balloon envelope and basket, as well as dents and scratches to the truck and trailer.