The first C-33 built (S/N 36-70) was modified at the Douglas factory and became the sole C-38. The primary modification done to the plane was to replace the DC-2 style aft fuselage and tail with a DC-3 style tail section. The hybrid nature of this modification earned the plane the unofficial nickname "DC-2½".
Besides the changes to the tail, the C-38 was fitted with more a powerful version of the Wright R-1820 Cyclone radial engine. The new engines generated 930 hp each and were fitted with larger diameter constant speed propellers. A taller main landing gear was added to the plane to give the proper propeller ground clearance while taxiing.
The successful flight test program conducted with the C-38 led to a follow-on order for 35 production aircraft designated C-39s.
After testing was completed, the C-38 was used as a staff transport and served throughout World War II with the Army Air Forces until the spring of 1945.
TECHNICAL NOTES: Engines: Wright R-1820-45 radials of 930 hp each Maximum speed: 208 mph Cruising speed: 170 mph Range: 1,100 miles Service ceiling: Approx. 20,000 ft. Span: 85 ft. 0 in. Length: 61 ft. 6 in. Height: 19 ft. 7 in. Weight: 18,500 lbs. maximum gross weight Crew: Two (pilot and co-pilot) Passenger capacity: 12 passengers or 2,400 lbs. of cargo Serial number: 36-70