DENISON, Tex. -- They have been performing stunts and high flying aerobatics for the past four days. Now ten pilots will be selected as the best in the nation.

The U.S. Aerobatics Competition started Sunday at the North Texas Regional Airport in Denison. On Thursday night, ten of the 22 pilots entered in the competition will be selected to compete in the World Championships next August.

Two national champions have already been determined in the categories of unlimited and advanced pilots. These pilots can do any kind of stunts, with airplanes of varying sizes.

"The best pilots in the world are here. Not only are they the best in the U.S. -- that's a given -- this is the U.S. National Championships, and the best pilots in the world. The flying quality has been superb. It has been just a game of inches,” emcee Mike Gallaway, coordinator, U.S. Aerobatics competition, said Thursday.

The aerobatics show is set for Friday, which will be the last day of the competition.