NACA cowling
The company's final aircraft was a freighter conversion the PT-6F. Built during 1937 and flown in 1938, the passenger cabin was modified as a cargo compartment with of stowage space, an NACA cowling was fitted, along with a variable-pitch propeller. A freight door was fitted to the fuselage and a loading hatch fitted in the roof. It was powered by a Wright R-975E-1 radial engine of slightly greater power.