12/31/2012. Remarks by Walter van Tilborg: "The S-1 Akromaster was a unlimited aerobatics aircraft designed and built by well-known aerobatic pilot Charlie Hillard (first American to become world champion aerobatics, in 1972). The project was sponsored by Maurice H. "Pappy" Spinks, hence the naming of the aircraft as the Spinks Akromaster.

The one-of-a-kind Akromaster first flew on 28 August 1968, registered as N7727, and was powered by a 200 hp Lycoming AIO-A1A engine. It was later reregistered N31SA and ended up in the EAA Museum. However, around 2011 it was sold to the Texan Air Museum at Slaton, Texas and a possible subject for a complete restoration."