Acme Sierra

The Acme Aircraft Co S-1 Sierra was an experimental aircraft of unusual configuration built in the US in 1948 to investigate the advantages of a pusher propeller configuration.<ref name=FLIGHT/><ref name=SIERRA/> Apart from this engine installation, the aircraft was unusual in having an Y-shaped tail incorporating ruddervators on the upper fins. The wing was shoulder-mounted on the fuselage and was unswept.

During the 1960s, the US aerospace manufacturer Northrop used the aircraft as a technology demonstrator for boundary layer control concepts.<ref name=SIERRA/><ref name=AEROFILES/>