An experimental VTOL aircraft, intended to take off and land as seen here. The identity of this aircraft is uncertain. Most say that it is the first prototype 138657, mysteriously painted as 138658. But reliable sources state that only parts (engine and props) of 138657 survived testing by Hiller Aircraft in the late 1950s. The second prototype 138658, left incomplete and without an engine when the design project was cancelled, went on display at NAS Los Alamitos and later at NOLF Imperial Beach until it disappeared in the early 1990s. Then in the mid 1990s the aircraft in this photo suddenly popped up in Florida. It seems likely then that this is in fact the real 138658 (with the props from 138657) and that it was painted correctly.
This photo was added on 18 July 2017, and has since been viewed 339 times.