On July 17, 2007, at 0715 mountain daylight time, an Aerostar International Inc. S81A, N5069B, was being operated as a sightseeing flight when a passenger sustained serious injuries during landing near Custer, South Dakota. Visual meteorological conditions prevailed on the day of the accident. The 14 Code of Federal Regulations Part 91 flight was not operating on a flight plan. The pilot and 11 other passengers were uninjured. The local flight originated at 0630 near Custer, South Dakota. The pilot provided a written statement in which he states that at the time of the balloon launch, the winds were calm, but during landing the winds were "a little stronger than forecast but nothing unusual for the Hills... ." He stated that he briefed the passengers for a windy landing, and the balloon landed "...going to 10-12 mph." The basket then tipped over on its side and slid 20 feet across grass and a "few" rocks. The passenger reportedly received a broken ankle during landing.