What happened
On January 11, 2010, at approximately 09:39 UTC, a mid-air collision occurred between two hot air balloons near Praz sur Arly, France. The first aircraft, a Cameron A160 with registration F-GHKT, operated by Alpes Transport, was conducting a commercial flight. The pilot had previously contacted the flight director via the self-information frequency to obtain takeoff authorization. While flying toward Megève at an altitude of approximately 720 feet, the aircraft passed near the takeoff platform without providing traffic information.
Shortly after, the pilot of an Ultra Magic S1 30, registration F-GOBI, contacted the same frequency to request takeoff clearance. After receiving authorization, the F-GOBI departed the platform with four passengers on board. During the ascent, the envelope of the F-GOBI struck the basket of the F-GHKT. The impact caused the F-GOBI envelope to tear across six panels and ignited the base of the balloon. The pilot was forced to perform an emergency descent, during which the basket struck the ground with significant force.
The investigation
The investigation examined the flight sequences of both aircraft, the meteorological conditions, and the organizational structure of the "20th Montgolfiades" aerial event. Investigators reviewed radio communications on the 122.25 MHz frequency and analyzed GPS data from the F-GOBI to reconstruct the flight path. The investigation also looked into the roles of the flight director and deputy flight director, noting that both were in flight at the time of the accident. The weather was found to be stable with clear skies and light winds, providing good visibility.
Findings
- The collision was caused by the F-GOBI envelope striking the basket of the F-GHKT during its ascent.
- The pilot of the F-GHKT did not provide traffic information to other aircraft when passing near the takeoff platform.
- The impact resulted in one serious injury among the passengers of the F-GOBI and no fatalities.
- The F-GOBI envelope sustained extensive damage, including tearing and fire.