Piper PA-19 / L-18
Early in 1948 Piper was developing the PA-19, which was a version of the PA-11 cub Special for the U.S. Army. Only three were built and the first of them, N5011H (Ser. No. 19-1), would serve as the certification test bed for the installation of the Continental C-90-12F, Lycoming O-235-C1 and O-290-D.
The PA-11 airframe was unchanged, except for a revised center section and the use of the more rounded rudder that was first used on the J-4 Cub Coupe. A sporty 90hp Continental-powered version of the Vagabond with Clipper wings, which was to be a mate with the 90hp PA- 11 for the 1949 model year.
Military orders for the PA-19 that Piper Aircraft hoped for did not immediately materialize, so the company decided to ''civilianize'' the design and market it as the Super Cub. Rather than advancing to the next model designation, which would have been PA-20, Piper chose to go backward and assign the unused PA-18 designation to the Super Cub.
Ot the three PA-19s were built: the first became the test bed for the PA-18-90 and -105 models; the second example became the test bed forthe PA-18-125 and -135; and the third was built and sold to the Department of the Interior and used by the Fish and Game Commission. This PA-19 existed in 2009 and was flying in Alaska.