Kubicek BB100 N355WC accident near St. Helena, California

Probable cause

The balloon pilot's encounter with unforecasted wind, which resulted in his decision to land in unsuitable terrain and a subsequent hard landing. Contributing to the severity of passenger injury was the pilot’s failure to provide a proper safety briefing.

NTSB analysis

The pilot departed on a routine flight, after reviewing the weather forecast, including wind and temperatures aloft. Additionally, he received weather information from his boss, who used pilot balloons to find prevailing winds, that the winds were favorable to their southern direction of flight. After an uneventful departure, the balloon started to drift northwest, but the accident pilot rapidly climbed to 3,000 ft at which point the balloon was diverted by winds from the northwest. According to passengers, the balloon pilot did not provide any safety instructions or emergency procedures prior to departure, nor did he during the accident flight until his first landing attempt. After about 1 hour and 45 minutes of flight the pilot decided to land on a small plot of terrain as he was unfamiliar with the terrain east of their position. The pilot did not recite any safety instructions prior to the balloon's impact with the ground, but instead he informed the passengers to brace for impact. The balloon impacted a blackberry bush, which likely absorbed some of the vertical energy. After a brief ascent, the balloon impacted the ground hard a second time and came to rest. One passenger was seriously injured.

It is likely that the pilot balloons released by the company owner to find the prevailing winds indicated desirable winds at lower altitudes. As the wind was not forecasted to be in a southeast direction below 3,000 ft.

The balloon pilot's encounter with unforecasted wind conditions likely resulted in his decision to land in unsuitable terrain, which resulted in a hard landing and serious injuries. Further, although he did deliver some safety instructions during the flight, several passengers were unclear on the emergency procedure and the pilot did not clarify his instructions when prompted. Thus, the pilot's lack of a thorough and clear safety briefing may have prevented some of the passengers from securing themselves properly for the abnormal landing.

Text from the NTSB. Open the NTSB docket for WPR19TA110 for the full record.