HISTORY OF FLIGHT On September 29, 2010, at 0606 coordinated universal time, a 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 (ATC) radar over international waters of the Adriatic Sea. The balloon and the pilots were located on December 6, 2010. The balloon was destroyed and the commercial pilot and commercial-rated copilot were killed. A range of meteorological conditions prevailed over the 4 days of the flight that originated at Bristol, England, on September 25, 2010, at 2329 coordinated universal time. According to the Italian Agenzia Nazionale Per La Scurezza del Volo (ANSV), the last radio and radar contact between the Brindisi, Italy, air traffic control center and the balloon occurred at 0606. The target identified as the missing balloon was descending at a high rate when it was lost from radar about 42 degrees, 10 minutes north latitude, and 16 degrees, 8 minutes east longitude. Examination of communications transcripts from Italian air traffic control revealed that the crew reported thunder and lightning in the vicinity of their balloon in the final minutes of the flight. At 0602, the pilot reported, " 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 the balloon was tracking 187 degrees magnetic at 13 knots, and "we are going down quite fast towards the sea.” There were no further transmissions from the balloon's crew. The Italian Coast Guard coordinated a six-day search using their ships, U.S. Navy aircraft, and a remotely-piloted underwater vehicle. No evidence of the balloon or its crew was immediately discovered. On December 6, 2010, a commercial fishing vessel snagged, and then recovered the balloon's basket, envelope, and the remains of the crew. 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 the Court to conduct an investigation for the Court. The Technical Advisor provided a comprehensive report at the completion of his investigation. PERSONNEL INFORMATION The pilot held a commercial pilot certificate with a rating for lighter-than-air-balloon. His most recent FAA third class medical certificate was issued July 9, 2009. The pilot reported 1,850 total hours of flight experience on that date. On his entry application prior to the race, the pilot declared 2,087 total hours of flight experience, 1,450 hours of which were in gas-filled balloons. The copilot held a commercial pilot certificate with a rating for lighter-than-air-balloon. Her most recent FAA second class medical certificate was issued December 12, 1984. The copilot reported 0 total hours of flight experience on that date. On her entry application prior to the race, the copilot declared 1,250 total hours of flight experience. The copilot did not declare her total hours of flight experience in gas-filled balloons, but instead declared her experience as 30 flights in gas-filled balloons. Media reports, as well as anecdotal evidence from the staff at the Gordon Bennett Race and the Albuquerque International Balloon Fiesta, Inc., revealed that the pilots were a renowned, champion, balloon racing crew who held several world records. AIRCRAFT INFORMATION According to Federal Aviation Administration (FAA) records, the balloon was manufactured in 2001, and issued a standard airworthiness certificate on June 6, 2005. Original maintenance records for the balloon were not immediately available; however a copy of the balloon's most recent annual inspection record revealed the inspection was completed July 28, 2010, at 195 total aircraft hours. METEOROLOGICAL INFORMATION A meteorologist well known for providing forecasts, route-planning, and advice to record-setting balloonists was consulted by the crew during the accident flight by telephone. In a conversation 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 the forecast weather. He said, "I tried to change their mind because of the forecast bad weather in the South but...without results." In a conversation on the morning of the accident, the crew reported they were drifting slowly in light winds, and that large, cumulonimbus clouds with showers were 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, 2010, depicted an area of cumulonimbus clouds developing in the vicinity of the last coordinates. The radiative cloud top temperature was between -28 to -30 degrees Celsius which corresponded to cloud tops in the range of 25,000 to 26,000 feet. The visible imagery indicated some signs of transverse banding on top of the anvil, which also implied strong vertical shears, turbulence, and thunderstorms in the area. WRECKAGE AND IMPACT INFORMATION The basket and the envelope of the balloon were examined by the Technical Advisor to the Italian Prosecutor. The 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. Additional Information The last radar contact with the flight placed the balloon over international waters. In accordance with the International Civil Aviation Organization rules, the country of registry of the accident aircraft is responsible for investigation of aircraft accidents occurring in international waters.