The Bell L-39-2 used by the U.S. Navy to study swept wings in its second configutation with fully swept wings for the X-2 program. The USN contracted with Bell for the modification of two P-63C-5 Kingcobras which would be fitted with a pair of wings swept back at 35 degrees, with a short inboard straight section. The wings carried adjustable leading edge slats and trailing-edge flaps. All armament was deleted and the rear canopy was faired over. These two planes were redesignated L-39-1 and L-39-2 respectively. The rather odd designation for a Navy aircraft was gotten by using the Navy's code letter for Bell (L) and the company's model number (39). The L-39-1 flew for the first time on April 23, 1946. Both aircraft tested a series of leading edge slat configurations of different designs. L-39-1 went to the NACA for continuing flight tests, whereas L-39-2 remained at Bell. L-39-2 was later fitted with a completely swept wing of a design planned for the X-2 experimental rocket-powered research aircraft.
{{Information |Description=The Bell L-39-2 used by the U.S. Navy to study swept wings in its second configutation with fully swept wings for the X-2 program. The USN contracted with Bell for the modification of two P-63C-5 ''Kingcobra''s which would be fi