From: Joseph F Baugher <jfb@ihlpl.att.com>
Subject: Twenty-third in the Series--the Curtiss XP-23
Keywords: modified P-6E, good-looking airplane
Organization: AT&T Bell Laboratories -  Naperville, Illinois
Date: Thu, 1 Oct 1992 12:29:23 GMT


From Joseph F Baugher <jfb@ihlpl.att.com>

The Curtiss XP-23 was the last biplane fighter design to be produced by 
the Curtiss company, and was perhaps one of the best-looking fighter 
biplanes ever produced by any manufacturer.  

The last P-6E in the USAAC order (Ser No 32-278) had been held back at 
the Curtiss factory for tests.  It was completed with an entirely new 
monocoque aluminum fuselage, new tail surfaces, a new nose, new 
landing gear, and a turbosupercharged and geared Curtiss G1V-1570-C 
engine.  A three-bladed propeller was fitted.  The nose was much 
sharper and more pointed than that of the P-6E, giving a much more 
aerodynamically-clean appearance.  The cooling radiator was mounted on 
the underside of the fuselage between the landing gear legs, just as 
it was on the P-6E.  The wings had the same design as the P-6E, but 
were of all-metal construction rather than wood.  However, the wings 
still had a fabric covering.  

The result was an airplane quite different in appearance from the 
P-6E.  Since it was essentially a new design, the aircraft was 
redesignated XP-23 by the USAAC.  The XP-23 was delivered to the USAAC 
on April 16, 1932.  Weights were 3274 lb empty, 4124 lb gross.  
Maximum speed was 180 mph at sea level, 223 mph at 15,000 feet.  
Initial climb was 1370 ft/min, service ceiling was 33,000 feet, and 
range was 435 miles.  Armament was one 0.50-cal and two 0.30-cal 
machine guns, all mounted in the nose.  

Although the XP-23 was the fastest biplane fighter yet produced and 
had an improved altitude performance, the USAAC recognized that the 
era of the biplane fighter had finally come to an end.  Since they had 
already ordered the Boeing P-26A monoplane fighter, the Army opted not 
to go ahead with an order for production examples of the P-23.  

Even though no production orders were forthcoming, tests still 
continued with the XP-23.  The XP-23 designation was switched to YP-23 
when the status changed from "experimental" to "service test".  As 
YP-23, it had its supercharger removed and the three-bladed propeller 
was replaced by a two-bladed unit.  This airplane was later used in a 
rather interesting test to determine the effects of radiator drag on 
high-speed aircraft.  For a brief period, the aircraft was flown 
without any radiator at all, the cooling water being pumped through 
the engine from an isolated tank and discharged overboard rather than 
being recirculated.  

Sources: 

  "United States Military Aircraft Since 1909", Gordon Swanborough and 
  Peter Bowers, Smithsonian Institution Press, 1989.  

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

  "Curtiss Aircraft: 1907-1947", Peter M. Bowers, Naval Institute Press, 
  1987.  

  "The Curtiss Army Hawks", Peter M. Bowers, Aircraft in Profile, 
  Doubleday, 1969.  

Joe Baugher       AT&T Bell Laboratories    2000 North Naperville Road 
		  Naperville, Illinois 60566-7033.   (708) 713-4548


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