Developed originally as the Porterfield Zephyr, under Approved Type Certificate (ATC) 2-530,[2] it is a light-weight version of the earlier Model 35 Flyabout for use as a pilot trainer.

Though roughly in the same general class with the tandem-seat Piper Cub, Aeronca Champ, and Interstate Cadet -- and the side-by-side seating Aeronca Chief, Taylorcraft BC-12D and Luscombe 8 -- the tandem-seat Porterfield is visually distinguishable from them by its twin parallel wing struts on each side (compared to the V-shaped struts on the other planes), and by its largely symmetrical airfoil wing (similar curvature top and bottom).

In 1940, under ATC 720,[2] the power was again upped to the popular 65-horsepower Continental A-65, pushing cruise to 100 mph, with a 500-pound useful load permitting a 300-statute-mile range.

Over 100 Porterfields remained active with private pilot owners in the United States and other countries in 2001.

Data from The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985), 1985, Orbis Publishing, Page 2760 and Simpson, 2001, p.442.General characteristics Performance