James S. McDonnell graduated Princeton 1921, qualified pilot at Army (Brooks) San Antonio, obtained MIT Master’s degree and spent inter-war years as designer—e.g. for Ford, Hamilton, Martin—before starting MAC (McDonnell Aircraft Corp.) on second floor of small building at Lambert Field, St Louis, 6 July 1939. With Garrett C. Covington (his former assistant at Martin) designed XP-67 fighter (6 January 1944) whilst building Fairchild AT-21 Gunners at Memphis. Navy awarded contract for XFD-1 twin-jet Phantom (26 January 1945) and F2H Banshee (11 January 1947, 895 built). Rotary-wing work included XHJD Whirlaway, in 1946 largest helicopter then flown outside Germany, XH-20 ramjet tip-drive, Army XV-1 (first aircraft to convert from rotor-supported to wing-supported flight) and Model 120 (1958) with payload 163% of empty weight. XF3H Demon (7 August 1951) was delayed by unsuitable engine but eventually matured as F3H-2/2M/2N. XF-88 Voodoo led to powerful F-101 Voodoo (29 September 1954) attack, recon and all-weather interception aircraft. Model 119 USAF UCX led to Model 220 4-jet executive aircraft, while new teams produced 1-man Mercury and 2-man Gemini space capsules and various missiles and decoys. XF4H-1 Phantom II (27 May 1958) led to biggest non-Soviet fighter programme since F-86 (5,157). While this was in full swing bid to merge with Douglas accepted, MAC becoming MCAIR, McDonnell Aircraft Company.