Firefly Balloons, Inc FIREFLY 10 N1623L accident near Temecula, California

Probable cause

The pilot's failure to follow the Landing checklist and his inadvertent contact with the blast valve after landing, which released propane that was then ignited by an undetermined source.

NTSB analysis

After a 1-hour local sightseeing flight, the commercial pilot landed the balloon, disembarked some passengers, and kept a few passengers on board as he moved the balloon to a trailer. The pilot reported that, after setting the balloon down on the trailer, he extinguished the burner's pilot light and then took the burner down from the flight position to put it in the storage bag attached to the side of the basket. While putting the burner in the bag, he bumped the blast valve, and the burner then released propane, which ignited and resulted in a fire; the ignition source was not determined. The pilot and four passenger sustained serious injuries.

The Landing checklist in the Balloon Flight Manual stated, in part, that pilots should ensure that all of the valves were firmly closed before touchdown and should bleed all of the fuel lines after landing. However, a postaccident interview with the pilot revealed the he did not shut off the appropriate valves or bleed the system of gas after he extinguished the pilot light. Therefore, it is likely that the pilot's failure to follow the Landing checklist allowed the burner to release propane when he inadvertently bumped the blast valve after landing.

Text from the NTSB. Open the NTSB docket for WPR14LA049 for the full record.