E-1927 The Bell Aircraft Corporation X-1E in 1955 on the Rogers Dry Lakebed near the NACA High-Speed Flight Station, Edwards, California. The X-1E was notable for being shorter, with a thinner wing than the X-1A, -B, and -D. Aerodynamic heating caused the ailerons, rudder, and elevators to remain unpainted throughout the X-1E flight test program. When the ventral fins were added, they were left unpainted too. On August 31, 1956, the aircraft reached a top speed of 1,480 miles per hour Mach 2.24. 1955 NASA Photo / NACA/NASA