Of the many aircraft models Cessna sold to the military over the years, perhaps the most successful (if success is measured in numbers sold) was the series based on the T-50 Bobcat light twin transport. Work on the original prototype, bearing c/n 1000 and registration number NX20784, began in 1938. Dwane Wallace completed the 20 minute initial test flight himself on 26 March 1939. The T-50 was a five place, retractable gear aircraft with a low wing and a pair of 225 horsepower Jacobs L 4MB radial engines driving Curtiss Reed fixed pitch propellers.

A feature unique to the prototype was the pronounced V shape of the windshield. The T-50 wing spars were constructed of laminated spruce with the truss style ribs fashioned from spruce and plywood. Plywood covered the wing leading edge and the outboard portions of the wing tips.

The T-50 prototype was tested for more than 100 flying hours and was eventually modified into the production configuration. The V shaped windshield was replaced with a curved one, rear windows with a curved trailing edge replaced the prototype's angular ones, and the vertical tail was resized and reshaped. Hamilton Standard 2B 20 213 hydraulically-actuated, constant speed, non featherable propellers replaced the original fixed pitch propellers. The 225 horsepower L 4MB engines were retained, albeit rated at 245 horsepower for takeoff. The prototype was eventually sold to Pan American Airways and registered in Mexico as XA BLU. In 1941, this aircraft was completely refurbished by the factory and reassigned c/n 1000A.