 Working in cooperation with the French Air Force, director Gérard  Pirès was able to get some of Frances top gun pilots to do the  aeronautic dogfights that were used in the film. Initially at the  start of the shoot, the Air Force had some particular rules  regarding the minimum distances the aircraft could be together or be  above the ground, but by the end of principle photography, the  daring pilots got permission to bend the normal safety rules, thus  allowing them to do maneuvers normally never seen (or possible)  outside of actual combat. By the final days of filming, the initial  minimum distance the pilots could fly above the ground (500 feet)  had dropped to a tiny 10 feet, and the distance between the planes  in the air (a varying range, usually of several hundred feet) had  been reduced to a minuscule 3 feet, thus allowing some amazing shots  that could otherwise never have been pulled off.