Subject: Number Eighty-Four in the Series--Republic P-84 Thunderjet

From: [email-masked]
Date: 15 Jul 93 16:16:28 GMT

>From [email-masked]

The Republic Thunderjet/Thunderstreak/Thunderflash family of 
jet-powered fighter-bombers and reconnaissance aircraft had its origin 
in a 1944 company-financed design study for a jet-powered replacement 
for the famed P-47 Thunderbolt.  At first, Alexander Kartveli and his 
team at the Republic Aircraft Corporation considered a straightforward 
jet adaptation of the P-47 airframe, but soon decided that such a 
design was impractical and began over again from scratch.  They 
settled on a cantilever low-wing monoplane with straight, laminar-flow 
wings and cantilevered horizontal tailplanes mounted halfway up the 
vertical tail.  A large airbrake was to be installed in the belly of 
the aircraft, just underneath the cockpit.  The engine selected was 
the General Electric TG-180 (J35) turbojet.  This engine had an axial 
flow, which offered less fuel consumption than that of the 
centrifugal-flow engines of earlier jet fighters such as the Lockheed 
P-80 Shooting Star.  The smaller diameter of the axial-flow engine had 
the additional advantage in that it allowed the use of a more 
streamlined, low drag fuselage.  The intake for the jet engine was to be 
mounted in the nose.  The pressurized cockpit was to have a teardrop 
canopy and was to be equipped with an ejector seat.  

Since range as well as high speed was an important consideration, it 
was necessary to forego a thin profile wing in favor of an airfoil 
section that was thick enough to carry fuel tanks and landing gear.  
The critical Mach number of this wing was considerably lower than that 
of the fuselage, and was the primary limiter of performance on early 
P-84 models.  

The USAAF liked what they saw, and ordered three prototypes and 400 
production examples in March of 1945.  The designation P-84 was 
chosen.  However, with the coming of victory in the Pacific, all 
existing military aircraft orders were suspended pending a review of 
postwar needs.  Most outstanding orders were cancelled in their 
entirety, but on January 15, 1946 the USAAF confirmed its order for 15 
YP-84A service test aircraft and 85 production P-84Bs.  

The first XP-84 (serial number 45-59475) was completed in December of 
1945, and was powered by a 3750 lb.st. General Electric J35-GE-7 
turbojet.  It was partially disassembled and flown from the factory at 
Farmingdale, New York to Muroc AFB in California aboard the Boeing 
XC-97 transport.  The XP-84 took off on its maiden flight on February 
28, 1946, piloted by Major William A. Lien.  It was the first new 
American fighter to have its maiden flight after the end of World War 
II.  

In tests, the XP-84 achieved a maximum speed of 592 mph at sea level.  
Normal range was 1300 miles, and an altitude of 35,000 feet could be 
attained in 13 minutes.  Weights were 9080 pounds empty, 13,400 pounds 
gross, and 16,200 pounds maximum.  

The second XP-84 flew in August 1946.  On September 7, 1946, this 
XP-84 set a new American speed record of 611 mph.  However, that very 
same day, the record was snatched away by the Gloster Meteor, which 
reached 616 mph.  

Sources:

  Fighters of the United States Air Force, Robert F. Dorr and David Donald,
  Temple Press Aerospace, 1990.

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

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

  United States Military Aircraft Since 1909, Gordon Swanborough and
  Peter M. Bowers, Smithsonian, 1989.

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