The new design was intended to be developed as a kit aircraft initially and then later to be type certified, although certification was never completed.
The official company designation for the production kit aircraft is SX300, although some owners have registered them as SX-300 and SX 300.
The engine cowling is made from composite material and is based on Swearingen's design he employed in the Piper PA-30 Twin Comanche.
The Lycoming IO-540 powerplant is mounted using a 7.25 in (18.42 cm) propeller extension and is offset 2° right and 1.5° down for P-factor effects.
The company indicated that production ended due to lack of progress in type certifying the design, but Apfelbaum indicates "the more likely reason is that a turboprop prototype shed its wings, leading to a fatal accident during a demonstration, which ultimately diminished the interest of the military.
[3] In a 2023 review for AVweb, Johnathan and Julia Apfelbaum concluded, "the SX300 doesn’t just look like a thoroughbred rocket ship of an aircraft—it really is.