On April 13, 2005, about 0800 Pacific daylight time, a Firefly Balloons, Inc., Firefly 11, N15001, made a hard landing in an open field near Saint Helena, California. The balloon was not damaged. Neither the commercial certificated pilot nor seven of the eight fare-paying passengers were injured. The eighth passenger was seriously injured during the touchdown sequence of the hard landing. The balloon was owned and operated by Calistoga Balloons, LLC., Calistoga, California. Visual meteorological conditions prevailed during the sightseeing flight, and no flight plan had been filed. The flight was performed under the provisions of 14 CFR Part 91, and it originated from Calistoga about 0700. The pilot reported to the National Transportation Safety Board investigator that during the flight he had varied the balloon's altitude from 500 to 3,000 feet above ground level, and the cruise portion of the flight had been uneventful. The pilot indicated that upon entering a wider area of the Napa Valley the winds aloft should have slowed, but they did not. Therefore, he decided to land as soon as possible, having the belief that the wind speed might increase if he continued the flight. During the descent to an open field, the balloon drifted over a row of estimated 30- to 40-foot-tall trees. The wind speed suddenly increased to between 10 and 12 miles per hour. The pilot reported that he advised the passengers to prepare for a possible hard touchdown, and during the final seconds of flight he used both burners at maximum power to slow the descent rate. However, a wind shear was encountered upon drifting downwind over the trees. The balloon abruptly descended, and the touchdown was "firm." The basket remained upright, and it stopped dragging on the ground in about 30 feet.