I don't know that USAF pilots ever had .45s. They had .38s at one time, since replaced by the M-9, 9mm. Many of course "requisitioned" .45s if they could, or supplied their own. I had a friend, not a pilot, but he did fly on occasion, who had his own .44 and/or .357 magnum wheelgun to keep him company at night over the Ho Chi Minh Trail.