The Fairchild XC-31 was an experimental cargo aircraft built for the U.S. Army Air Corps. Note the retractable landing gear on this large, strut-braced monoplane. Fairchild XC-31 (Kreider-Reisner): The large XC-31, built by the Kreider-Reisner division of Fairchild aircraft was used, in part, for icing studies while with the NACA at Langley. This is the only example of the type ever built. Photo dated: 10/10/1938, from NASA Langley Research Center – Multimedia Repository.
From Aero Digest, April, 1935:
Fairchild Aircraft Corporation, Hagerstown, Maryland
• One-pilot high-wing monoplane. Wright Cyclone R-1820-25 engine, 750 horsepower. Span 84 feet. Length overall 55 feet. Height overall 15 feet 10 inches. Wing area 802 square feet. Power loading 17.4 pounds per horsepower. Wing loading 16.2 pounds per square foot.
Empty weight 7322 pounds. Useful load 5678 pounds. Payload 3720-4320 pounds. Gross weight 13,000 pounds. Fuel capacity 200 gallons. Oil capacity 14 gallons.
Maximum speed 167 miles per hour. Cruising speed 140 miles per hour. Landing speed 52 miles per hour. Cruising range 750 miles.
Fuselage: fabric covered; welded chrome molybdenum steel tubing; tie rod bracing in most of upper, lower and cross panels; gusset plates, tie rods, lugs and fittings welded to structure are of chrome molybdenum sheet and bar steel; superstructure for pilot’s windshield, floor, seat, instrument board support, etc., chrome moly tubing, welded to fuselage; all corrosion proof. Wing: cantilever stub wing chrome moly steel tubing with steel fittings throughout; main wing fabric covered, all-metal; spars of single solid web type with extruded angles as flanges; ribs of channel section cap strips and square aluminum alloy tubular truss members connected by aluminum alloy forgings and rivets; leading edge of metal; Zap-type flaps, all-metal construction; manually or electrically operated. Tail group: fabric covered; all-metal cantilever fin; aluminum alloy rudder with sheet metal nose; trim tab provided at trailing edge of rudder. Retractable landing gear equipped with 40 X 10 tires, hydraulic wheels and brakes. Plane controls operated by cables.
Standard equipment includes three-bladed Hamilton Standard controllable pitch propeller, Pyrene fire extinguisher, M8 airway flares. Plane equipped for transportation of engines, troop transporting, ambulance carrier and passenger carrying; has portable desk, and chute for dropping containers by parachute. Also see data in December, 1934, AERO DIGEST.