Milburn Grant "Mel" Apt[1] (April 9, 1924 – September 27, 1956) was a U.S. Air Force test pilot, and the first man to attain speeds faster than Mach 3.

He graduated from the Experimental Flight Test Pilot School at Edwards Air Force Base (Class 54B) in September 1954.

The X-2, initially an Air Force program, was scheduled to be transferred to the civilian National Advisory Committee for Aeronautics (NACA) for scientific research.

The service requested and received a two-month extension to qualify another Air Force test pilot, Apt, in the X-2, and attempt to exceed Mach 3.

At 19,977 m (65,541 ft), the X-2 reached Mach 3.196, making Apt the first man to fly more than three times the speed of sound.

The additional time to slow before turning may have put him beyond safe gliding range of his planned runway.

Too late, Apt attempted to bail out and was killed when the capsule hit the Edwards bombing range.

Col. Frank K. Everest, an experienced X-2 pilot, had been critical of the relatively new detachable cabin: "Colonel Everest told reporters in Buffalo that a pilot using the detachable device would be thrown against the instrument panel with terrific force when the parachute braked it.

"[13][14][15] Prospective X-15 pilots were subsequently shown the on-board film of Apt's fatal crash, taken by a stop-frame camera mounted behind him in the cockpit.