The wife of American adventurer Steve Fossett has filed a court petition to get him declared legally dead.
Steve Fossett has set many world records as pilot, balloonist and sailor
Mr Fossett has been missing for three months since his single-engine plane disappeared over the Nevada desert.
In a written statement Peggy Fossett said that it was a difficult day for her family, but that they now "must accept that Steve did not survive".
There has been no trace of the 63-year-old aviator since he took off from Yerington, NV, on 3 September.
The flight had been expected to last about three hours and Mr Fossett was not required to, and did not, file a flight plan.
"As painful as it is for Mrs Fossett, other members of the family and his many friends, it is time to initiate this process," lawyer Michael A LoVallo, who filed the petition in Cook County Circuit Court, was quoted by the Associated Press as saying.
The move is a step towards taking control of Mr Fossett's estate. The court papers said Mr Fossett's "wealth is vast, surpassing eight figures in liquid assets, various entities and real estate".
The petition said there was no chance that he could have survived in the soaring desert temperatures, even if he lived through a crash.
No trace was found in the mountainous, inhospitable terrain
"Fossett did not have any reason to disappear," AP quoted the petition as saying. "Fossett was happy and passionately involved in his pursuit of adventure."
In the weeks after Mr Fossett's disappearance Nevada Civil Air Patrol carried out a series of extensive aerial searches in both Nevada and California.
At the height of the operation 45 planes were scouring the mountainous terrain.
The search, also joined by many private planes, did discover several previously undiscovered downed planes - some of which were decades old - but neither Mr Fossett, nor his plane, were found.
Mr Fossett reportedly took the flight to look for locations that could be used for an attempt on the land speed record.
Mr Fossett has racked up about 100 world records. In March 2005, he became the first to fly a plane solo, non-stop around the globe.