Flight Testing at Edwards AFB in the 1950s

This article is a memoir of Harry Schmidt, a Pratt & Whitney test pilot at Edwards AFB during the mid-1950s. Schmidt recalls that the J57 was critical to P&W’s long-term success, so the testing program was vital both to the United States Air Force (USAF) as well as to P&W. Early in the testing program, the engine would stall even in a shallow bank; however, after a couple of months, the team was able to complete hard turns without a stall. To solve the high-speed stall problem, P&W engineers tweaked the engine turbine vanes to provide greater stall margin. In the fall of 1955, the team received its F-101, a twin-engine fighter with two J57s and a top speed of about Mach 1.5. Because the team was operating the fastest aircraft in the world, they figured they could also set an unofficial world’s altitude record by achieving max Mach at about 40,000’ and then climb trading airspeed for altitude.