Ballonbau Worner Gmbh NL-1000/STU N801NM accident near Adriatic Sea, A1

Probable cause

The crew's intentional flight into known adverse weather conditions, which resulted in destruction of the balloon envelope by lightning strike and the subsequent uncontrolled descent to the sea.

NTSB analysis

The balloon race crew was participating in a cross-continent race in Europe. Despite the advice and counsel of a renowned meteorologist who specialized in balloon-race route planning, the crew chose a route of flight where thunderstorms and other adverse weather phenomenon were predicted. Communications transcripts from Italian air traffic control revealed that, in the last moments of the flight, the crew reported thunder and lightning in the vicinity of the balloon, that they were losing altitude due to the snow, and ultimately stated that they were descending very fast towards the sea. The Prosecutor's Office in the Court of Lucia, Italy, claimed jurisdiction over the wreckage and the crew's remains and appointed a technical advisor to conduct an investigation. His examination of the envelope revealed thermal damage in the lower half of the envelope consistent with a lightning strike. Further examination revealed shredding in the lower half, and slices in the upper half consistent with a hydrogen detonation. The basket was deformed by impact damage, but displayed no evidence of thermal damage.

Text from the NTSB. Open the NTSB docket for ERA10LA511 for the full record.