History of Flight
On September 29, 2010, at 0606 coordinated universal time, the Ballonbau Worner hydrogen-filled balloon N801NM, operated by Peak Express Balloon as an entry in the Coupe Aeronautique Gordon Bennett 2010 International Gas Balloon Race, was lost from Italian air traffic control radar over international waters of the Adriatic Sea. The balloon and its two pilots were located on December 6, 2010. The balloon was destroyed and both pilots were killed. The flight had originated at Bristol, England, on September 25, 2010, at 2329 coordinated universal time, and meteorological conditions varied over the four days.
The last radio and radar contact between the Brindisi, Italy, air traffic control center and the balloon occurred at 0606. The radar target, identified as the missing balloon, was descending at a high rate when lost at approximately 42 degrees 10 minutes north latitude and 16 degrees 8 minutes east longitude.
Communication transcripts from Italian air traffic control showed the crew reported thunder and lightning near the balloon in the final minutes. At 0602, the pilot stated, "we are now being pushed down by the snow quite fast so just to put you aware of, we don’t have a problem just yet but it’s not a real good situation for us so we’ll keep you posted." At 0606, the pilot reported tracking 187 degrees magnetic at 13 knots and "we are going down quite fast towards the sea." No further transmissions were received.
The Italian Coast Guard coordinated a six-day search using their ships, U.S. Navy aircraft, and a remotely-piloted underwater vehicle, but no evidence was immediately discovered. On December 6, 2010, a commercial fishing vessel snagged and recovered the balloon's basket, envelope, and the remains of the crew. The Prosecutor's Office in the Court of Lucia, Italy, claimed jurisdiction and appointed a Technical Advisor to conduct an investigation.
Personnel Information
The pilot held a commercial pilot certificate with a lighter-than-air-balloon rating. His most recent FAA third class medical certificate was issued July 9, 2009, and he reported 1,850 total flight hours. On his race entry application, he declared 2,087 total hours, including 1,450 hours in gas-filled balloons.
The copilot held a commercial pilot certificate with a lighter-than-air-balloon rating. Her most recent FAA second class medical certificate was issued December 12, 1984, and she reported 0 total hours at that time. On her entry application, she declared 1,250 total flight hours and 30 flights in gas-filled balloons, but did not specify total gas balloon hours.
Media reports and anecdotal evidence indicated the pilots were a renowned, champion balloon racing crew who held several world records.
Aircraft Information
According to FAA records, the balloon was manufactured in 2001 and issued a standard airworthiness certificate on June 6, 2005. Original maintenance records were not immediately available, but a copy of the most recent annual inspection showed it was completed July 28, 2010, at 195 total aircraft hours.
Meteorological Information
The crew consulted a meteorologist well known for providing forecasts and route-planning to record-setting balloonists. On the evening before the accident, the crew stated their intention to maintain a southeasterly track, but the meteorologist attempted to dissuade them due to forecast bad weather, saying "I tried to change their mind because of the forecast bad weather in the South but...without results." On the morning of the accident, the crew reported drifting slowly in light winds and observed large cumulonimbus clouds with showers south of their position drifting eastward.
According to a Senior Meteorologist at the National Transportation Safety Board, infrared and visible satellite images at 0600 UTC on September 29 depicted an area of cumulonimbus clouds developing near the last coordinates. Radiative cloud top temperatures between -28 to -30 degrees Celsius corresponded to cloud tops of 25,000 to 26,000 feet. Visible imagery showed signs of transverse banding on the anvil, implying strong vertical shears, turbulence, and thunderstorms.
Wreckage and Impact
The basket and envelope were examined by the Technical Advisor to the Italian Prosecutor. The envelope exhibited thermal damage in the lower half consistent with a lightning strike. Shredding in the lower half and "slices" in the upper half were consistent with a hydrogen detonation. The basket was deformed by impact damage but showed no evidence of thermal damage.
Because the last radar contact placed the balloon over international waters, the country of registry (United States) was responsible for the investigation under International Civil Aviation Organization rules.