Designed and flown by Ron Beattie
and Walt Fellers, two North American Engineers who came to work
for the Northrop Division. The aircraft was built by the Acme
Aircraft Company (Sierradyne Inc.) Crawford and Keeney, at the
Torrance Airport in late 1948. The first flight was on 23 November
1953. It was built according to Goodyear
Racing Plane specifications. Although it was never entered in
any races, extensive data was obtained during its many flights.
This experimental aircraft was
built to investigate the advantages of a pusher propeller configuration.
It has a "Y" shaped tail incorporating ruddervators
on the upper fins, an unswept wing mounted midway up the fuselage,
an engine mounted directly behind the cockpit, and large air
scoops mounted in the forward end of both wing roots.
Artist's conception of the Northrop
A-9A
The aircraft was used by Sierradyne
in the 1960's to test and promote Northrop's and Dr Werner Pfenninger's
boundary layer control concepts. Northrop used it as a flying
technology demonstrator for the Air Forces AX close-support
aircraft design competition in 1972. The plane was never officially
considered a Northrop aircraft.