What happened
On October 6, 1962, a free balloon, registration HB-BIU, was conducting a flight near Schüpfen, Switzerland. The flight had departed from Schlieren near Zurich approximately three hours earlier. During the flight, the pilot decided to perform an early landing due to prevailing Bise winds, which were blowing at speeds between 35 and 40 km/h.
As the pilot attempted to bring the Augsburg N 8210 balloon to the ground at an altitude of roughly 6 to 7 meters, a sudden gust of wind caused the ground speed to increase significantly. The basket struck the ground hard and overturned, as the pilot had anticipated for such conditions. During the impact, one passenger was thrown from the basket, while the pilot was also ejected but remained momentarily caught by a rope loop at the basket edge. After the balloon ascended briefly, the pilot fell several meters onto the hard ground, sustaining severe spinal injuries.
Following the initial impact, the balloon—now significantly lightened by the loss of weight from the occupants—ascended to an altitude of approximately 100 to 150 meters. The unmanned balloon then drifted roughly 300 meters westward before descending into a young forest. During this final descent, another passenger remaining in the basket struck their back against the basket edge, resulting in further severe spinal injuries.
The investigation
The investigation examined the sequence of events leading to the basket overturning and the subsequent uncontrolled ascent and descent of the balloon. Investigators reviewed the weather conditions, noting northeast winds with gusts up to 20 knots and limited horizontal visibility. The inquiry also assessed the physical actions of the occupants during the landing maneuver and the structural state of the balloon's envelope following the impact.