The Boeing XP-9 (company Model 96) was the first monoplane
fighter aircraft
Fighter aircraft are fixed-wing military aircraft designed primarily for air-to-air combat. In military conflict, the role of fighter aircraft is to establish air superiority of the battlespace. Domination of the airspace above a battlefield ...
produced by the
United States aircraft manufacturing company
Boeing. It incorporated sophisticated structural refinements that were influential in later Boeing designs. The sole prototype exhibited unsatisfactory characteristics with its lack of pilot visibility directly leading to its cancellation.
Design and development
The XP-9 was designed in 1928 to meet the requirements of a
US Army request for a
monoplane fighter. Its primary contribution to aircraft design was its semi-
monocoque construction, which would become a standard for future aircraft. Boeing employed the structural features of the XP-9 into their contemporary P-12
biplane
A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While ...
fighter when the P-12E variant incorporated a semi-monocoque metal fuselage structure similar to that of the XP-9. The
undercarriage
Undercarriage is the part of a moving vehicle that is underneath the main body of the vehicle. The term originally applied to this part of a horse-drawn carriage, and usage has since broadened to include:
*The landing gear of an aircraft.
*The ch ...
arrangement of the P-12C had also been first tried out on the XP-9 and then transferred into the production model.
[''Pedigree of Champions: Boeing Since 1916'' 1969]
Operational history
The prototype XP-9, marked ''A 028-386'', was first flown on 18 November 1930. It had impressive stats on the specification sheet, but it quickly became apparent that its large (6 ft
chord
Chord may refer to:
* Chord (music), an aggregate of musical pitches sounded simultaneously
** Guitar chord a chord played on a guitar, which has a particular tuning
* Chord (geometry), a line segment joining two points on a curve
* Chord ( ...
) wing, which was placed atop the fuselage directly in front of the pilot, obstructed downward visibility so badly that simple landing maneuvers were hazardous.
Test pilots at the Army Test Centre at Wright Field found that the XP-9's inherent instability was so severe that immediate modifications were requested to increase the size of the vertical tail.
[Baugher, Joe. ''Boeing XP-9''. 6 June 1998. Access date: 17 March 2007.] An enlarged vertical tail surface with smooth metal skinning was introduced, but failed to effect any significant improvement, and this revised XP-9 was grounded for instructional airframe use in August 1931, after only 15 hours of test flying, due to the impossibility of its being landed safely.
[Eden and Moeng 2002, p. 74-77.]
Variants
;Model 96, XP-9: one built
;Y1P-9: option for five service test aircraft under the P-12D contract, option was not taken up
Operators (planned)
;
*
United States Army
Specifications (Boeing XP-9)
See also
References
Notes
Bibliography
* Eden, Paul and Moeng, Soph. ''The Complete Encyclopedia of World Aircraft''. London: Amber Books Ltd., 2002. .
* ''Pedigree of Champions: Boeing Since 1916, Third Edition'' (booklet). Seattle, WA: The Boeing Company, 1969.
External links
United States Air Force Museum: Boeing XP-9
{{Boeing model numbers
Boeing P-09
P-09, Boeing
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