Northrop XP-79

The Northrop XP-79, USAAF project number MX-365, was a rocket and jet-powered flying wing fighter aircraft, designed by Northrop. The pilot operated the aircraft in a prone position, permitting much greater g-forces to be resisted by the pilot in pitch. The XP-79 also used a welded magnesium monocoque structure instead of riveted aluminum.

Design and development

thumb|The MX-334

In 1942, Jack Northrop conceived the XP-79 as a high-speed rocket-powered flying-wing fighter aircraft. In January 1943, a contract for two prototypes under the XP-79 designation was issued by the United States Army Air Forces (USAAF).

It was planned to use a thrust XCALR-2000A-1 "rotojet" rocket motor from Aerojet that used mono-ethylaniline fuel and red fuming nitric acid (RFNA) oxidizer. However, the rocket motor, which used canted rockets to drive turbo-pumps was unsatisfactory and the aircraft was fitted with two Westinghouse 19B turbojets and re-designated XP-79B.

The XP-79 was built using a welded magnesium alloy monocoque structure with a leading edge thickness of which thinned out to at the trailing edge.

The pilot controlled the XP-79 through a tiller bar and intakes mounted at the wingtips supplied air for the unusual bellows-boosted split elevons which opened differentially to provide lateral (yaw) control, by increasing drag on one side of the aircraft, in addition to providing roll and pitch. Flight testing was concluded by 1 August 1944 and the two remaining aircraft were disposed of. MX-334 no.3 was written off on its second flight, on 10 November 1943, after Harry Crosby lost control in the prop-wash of the P-38 tug.

Testing

Following delays due to burst tires and brake problems during taxiing trials at Muroc dry lake, the XP-79B made its first flight on 12 September 1945. 15 minutes into the flight, control was lost for unknown reasons while performing a slow roll. The nose dropped, and the roll continued with the aircraft impacting the ground in a vertical spin. Test pilot Harry Crosby had attempted to bail out but was struck by the aircraft and died. Shortly thereafter, the project was canceled along with work on the second prototype.

Variants

Data from: Northrop Flying Wings: a history of Jack Northrop's visionary aircraft

|prime units?=imp

|crew=1

|length ft=13.98|span ft=37.99|height ft=7.58

|wing area sqft=278

|aspect ratio=5.19

|airfoil=NACA 66,2-018

|empty weight lb=5842|gross weight lb=8669

|fuel capacity=

|eng1 number=2|eng1 name=Westinghouse 19B|eng1 type=axial flow turbojet|eng1 lbf=1150

|max speed mph=547|cruise speed mph=480

|range miles=993|endurance=2.45 hours

|ceiling ft=40000

|climb rate ftmin=4000

|wing loading lb/sqft=31|thrust/weight=0.27

|guns= 4 x machine-guns

References

Bibliography

Pelletier, Alain J. "Towards the Ideal Aircraft: The Life and Times of the Flying Wing, Part Two". Air Enthusiast, No. 65, September–October 1996, pp. 8–19. .

External links

National Museum of the USAF Fact Sheet: Northrop XP-79B
Northrop XP-79