twa contracted its five stratoliners to the army air force's air transport command after pearl harbor. designated as c-75s, they flew 3000 transatlantic flights to africa and europe. twa also contracted to fly its c-54s and lockheed c-69 constellations. hughes and twa had developed the constellation in secret with lockheed, and hughes purchased 40 for twa's use in 1939, through his hughes tool company. on april 17, 1944, hughes and frye flew the twa constellation from burbank, california, to washington, d.c., in 6 hours 58 minutes. by war's end, 20 constellations had been built.