Subject: Number Seventy-Nine in the Series--Northrop XP-79B

From: [email-masked]
Date: 8 Jun 93 16:37:52 GMT

>From [email-masked]

The Northrop XP-79 originated in 1942 as an idea by John K. Northrop 
for a high-speed flying wing fighter aircraft powered by a rocket 
engine.  Near-sonic speeds were envisaged.  The idea was somewhat 
similar to that which eventually produced the Messerschmitt Me 163 
rocket-powered interceptor in Germany.  

The Northrop fighter project was to be powered by a 2000 pound thrust 
Aerojet rocket engine, with takeoff assisted by a pair of 1000 pound 
thrust rocket boosters which would be dropped after takeoff.  Northrop 
proposed that this airplane be flown by a pilot lying prone in the 
cockpit, since it was hoped that this would reduce strain on the pilot 
during violent maneuver and would present a minimum silhouette to 
enemy gunners.  

In January of 1943, the USAAF issued a contract for three prototypes 
under the designation XP-79.  The availability of jet engines led to a 
decision in March to use two Westinghouse 19-B turbojets in the third 
prototype, which was redesignated XP-79B.  

Since the layout of the fighter was so radical, it was thought that 
test glider prototypes be built to verify the validity of the concept.  
One of these was designated MX-324, and was fitted with a fixed 
tricycle landing gear.  The MX-324 was towed into the air by a P-38 on 
July 5, 1944, and became the first American-built rocket-powered 
aircraft to fly.  

Delays in the development of the Aerojet rocket engine caused the 
USAAF to cancel the two XP-79s, leaving only the XP-79B.  The serial 
number of the XP-79B was 43-52437.  The XP-79B was finally ready for 
flight testing in the summer of 1945.  The pilot lay prone in an 
unpressurized cockpit situated between the two turbojets.  The flying 
wing was of semimonocoque construction and was built largely of 
magnesium in order to save weight.  Instead of conventional ailerons, 
the wing had air intakes at the tips for lateral control, in much the 
same manner as the XP-56.  The aircraft was equipped with a pair of 
vertical tails, presaging the MiG-25 and the F-15.  The retractable 
landing gear consisted of four wheels, two each in tandem.  

The XP-79B was to use a rather unusual technique for destroying enemy 
aircraft.  The wing leading edge was reinforced so that it could slice 
off the wings or tails of enemy aircraft by ramming them!  And if that 
didn't work, the XP-79B was equipped with a more conventional armament 
of four 0.50-inch machine guns in the wing leading edge.  

The XP-79B was transferred to Muroc Dry Lake in June of 1945.  Flight 
testing was delayed by problems with bursting tires during ground 
taxiing trials.  On September 12, 1945, test pilot Harry Crosby 
finally took the XP-79B up in the air for the first time.  It flew all 
right for about fifteen minutes, but the plane then suddenly went into 
a spin from which it proved impossible to recover.  Crosby attempted 
to parachute to safety, but his chute failed to open and he was 
killed.  The XP-79B impacted in the desert and was destroyed in the 
resulting fire.  Magnesium burns very nicely.  :-).  

Although the mishap that cost Harry Crosby his life could have been 
corrected, the USAAF decided to abandon the project.  

Specification of the XP-79B:  Powered by a pair of 1365 lb. st.  
Westinghouse 19B turbojets.  Wingspan was 28 feet, length 14 feet, and 
height was 7 feet.   Wing area was 278 square feet.  Gross weight was 
8669 pounds.  Estimated performance included a maximum speed of 547 
mph at 20,000 feet, an initial climb rate of 4000 feet, a service 
ceiling of 40,000 feet, and a range of 993 miles.  The proposed 
armament of four 0.50-in machine guns was never fitted.  

Sources: 

  American Combat Planes, Ray Wagner, Third Enlarged Edition, Doubleday, 
  1982.  

  The American Fighter, Enzo Angelucci and Peter Bowers, Orion Books, 
  1987.  

Joe Baugher		AT&T Bell Laboratories   	
2000 North Naperville Road      Naperville, Illinois 60566-7033