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
In an aircraft with a pusher configuration (as opposed to a tractor configuration), the propeller(s) are mounted behind their respective engine(s). Since a pusher propeller is mounted behind the engine, the drive shaft is in compression in nor ...
configuration. Apart from this
engine
An engine or motor is a machine designed to convert one or more forms of energy into mechanical energy.
Available energy sources include potential energy (e.g. energy of the Earth's gravitational field as exploited in hydroelectric power gen ...
installation, the aircraft was unusual in having an X-shaped
tail
The tail is the section at the rear end of certain kinds of animals’ bodies; in general, the term refers to a distinct, flexible appendage to the torso. It is the part of the body that corresponds roughly to the sacrum and coccyx in mammals, r ...
incorporating
ruddervators on the upper fins. The wing was mounted midway up the
fuselage
The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...
and was unswept. During the 1960s, the US aerospace manufacturer
Northrop used the aircraft as a technology demonstrator for
boundary layer control
Boundary layer control refers to methods of controlling the behaviour of fluid flow boundary layers.
It may be desirable to reduce flow separation on fast vehicles to reduce the size of the wake (streamlining), which may reduce drag. Boundary l ...
concepts.
Specifications (S-1 Sierra)
See also
References
{{reflist
External links
Aircraft Ab – Ak#Acme Aerofiles
1940s United States experimental aircraft
Aircraft manufactured in the United States
V-tail aircraft
Single-engined pusher aircraft