Developed by Beech in 1934, the unique "staggerwing" was an instant success in general aviation, and became a valuable asset to the Navy as an executive transport. One of the aircraft, a Beech Model C-17R, was purchased and served in this capacity for two years. In 1939, the Navy purchased ten D-17 models, designating them GB-1s, and acquired eight more impressed from civil sources. The GB-1s were powered by the Pratt & Whitney R-985-48 engines of 400 horsepower. Following that, the Navy purchased a total of 342 GB-2s powered by the R-985-50 engine of 450 horsepower. Named "Traveller," the GB-2 served as both a liaison aircraft and as a transport to take ferry pilots to aircraft factories around the U.S. for pick up and delivery of new aircraft to the fleet. Some were also given to Britain under Lend-Lease for use as liaison aircraft.