He joined Lockheed in 1957, and in 1959 was chosen by Kelly Johnson as chief test pilot for the Skunk Works.[5]
As such, he assisted in the design of the cockpit of the A-12 as well as conducting the unofficial and official first flights of the aircraft and contributing to the resolution of initial instability issues.[6][7][5] In his role as chief test pilot Schalk interfaced extensively and significantly with systems engineers for the A-12, YF-12, and SR-71, conducting the first thirteen flights of the A-12, the first four flights in excess of Mach 3.0, reaching a top speed of Mach 3.287, and conducting subsequent engineering test flights above Mach 3.0 as engine, inlet, afterburner and other critical systems were evaluated and fine-tuned, with altitudes in excess of 90,000 feet.[8][1]
12Brasswell, Arnold (2004). Taps: A Supplement to Assembly Magazine. West Point, New York: Association of Graduates, United States Military Academy. p.37. Retrieved 16 May 2020.
