To speed up development, the first Constellation, c/n 1961, was purchased from Howard Hughes in May 1950 for $100,000 and modified as the Super Constellation prototype with the fuselage lengthened by 18ft 7 by (ca. 5,7m) with the addition of two sections, the first in front of the wing spar, and the second part behind the wing. Still powered by the Curtiss Wright R-3350 engines installed in 1945, the prototype made its first flight on October 13, 1950. After twenty-two hours of flight testing, the vertical stabilizers were enlarged by eighteen inches to increase directional stability.
