US millionaire adventurer Steve Fossett, missing after taking-off from an airfield in Nevada, has set 116 world records in five different sports, 76 of which still stand.
In 2006, he broke the record for the longest flight, spending nearly 77 hours in the air and covering more than 40,000km (25,000 miles).
A year earlier, Mr Fossett made the first solo non-stop flight around the world without refuelling in 67 hours.
As skipper with a 13-member crew, he beat the round-the-world sailing record in 2004, completing the voyage in 59 days and nine hours.
But he is perhaps best known for becoming the first person to fly around the world in a balloon in 2002, covering 31,266km (19,428 miles).
Mr Fossett has cheated death a number of times, with his friend Sir Richard Branson describing him as "a tough old boot".
After being inducted into America's National Aviation Hall of Fame in July, Mr Fossett said he would continue flying "because I'm not done".