The sole surviving RB-1 Conestoga twin-engined cargo transport. Built in 1944 for US Navy. Three prototypes and 17 production aircraft - this one as serial Bu39307. With increased US production of aluminium, the use of heavier stainless steel in aircraft became unnecessary and further large orders for the type by the USN and USAAF were cancelled. Flew as XB-DUZ postwar.