Aerostar International Inc RX-9 N9116M accident near Marathon City, Wisconsin

Probable cause

A hard landing as a result of unexpected high winds and gusts.

NTSB analysis

The pilot and four paying passengers departed in a free air balloon. The local area surface weather observations indicated that the winds were consistently from the northwest at 6 – 8 knots. Around the time of the balloon launch, the winds were observed to be 300 degrees at 6 knots. About 3 minutes after liftoff, the balloon was heading 180 degrees at 10 knots about 800 feet above ground level. The winds on the ground suddenly increased to about 25 mph, and the balloon experienced strong wind gusts. The pilot reported that about 9 minutes after takeoff, a big wind gust “caved in” half the balloon and the mouth was “almost shut.” The pilot decided to get the balloon on the ground at the nearest suitable field, and instructed the passengers to prepare for a hard landing. The balloon hit hard, bounced in the air about 30 feet, and traveled about 200 feet before it hit the ground again. The balloon tipped on its side and one of the passengers partially fell out of the basket, but was restrained by the pilot and a passenger. The wind dragged the basket about 125 feet where the passenger fell out the basket and into a ditch. The basket was dragged about another 60 feet before it came to a stop in another field. The passenger was seriously injured. The balloon sustained minor damage.

Text from the NTSB. Open the NTSB docket for CEN09CA358 for the full record.