From: Joseph F Baugher <jfb@ihlpl.att.com>
Subject: Number Forty in the Series--Curtiss P-40 (4 of 11)
Keywords: P-40F Warhawk, Kittyhawk II
Organization: AT&T Bell Laboratories -  Naperville, Illinois
Date: Tue, 29 Dec 1992 17:24:49 GMT


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


In 1941, P-40D Ser No 40-360 was fitted with a 1300 hp British-built 
Rolls-Royce Merlin 28 engine with a single-stage two-speed 
supercharger.  It flew for the first time on June 30, 1941.  This 
experimental P-40D could be distinguished from the P-40E by the 
absence of the top-mounted carburetor air scoop.  The Merlin engine 
did much to overcome the limitations imposed by the Allison, and a 
total of 1311 Merlin-powered examples were ordered under the 
designation P-40F.  

The P-40F and later versions were known by the name *Warhawk* in US 
service.  In British and Commonwealth service, they were known as 
*Kittyhawk*.  

The first 699 planes of the P-40F series had no dash numbers.  The 
P-40F-5-CU and later models had their fuselages elongated from 31 feet 
2 inches to 33 feet 4 inches in order to improve directional 
stability.  The P-40F-10-CUs had manual instead of electric cowl flap 
controls.  The P-40F-15-CUs had winterizing equipment, and the 
P-40F-20-CUs had a revised oxygen flow system for the pilot.  

The P-40F was powered by a Packard-built Merlin V-1650-1 
twelve-cylinder Vee liquid-cooled engine rated at 1300 hp for takeoff 
and 1120 hp at 18,500 feet.  Maximum speed was 320 mph at 5000 feet, 
340 mph at 10,000 feet, 352 mph at 15,000 feet, and 364 mph at 10,000 
feet.  An altitude of 10,000 feet could be attained in 4.5 minutes, 
and an altitude of 20,000 feet could be reached in 11.6 minutes.  
Maximum range was 700 miles at 20,000 feet (clean), 875 miles (one 43 
Imp gal drop tank), and 1500 miles (141.5 Imp gal drop tank).  Service 
ceiling was 34,400 feet.  Weights were 6590 pounds empty, 8500 pounds 
normal loaded, and 9350 pounds maximum.  Dimensions were 37 feet 4 
inches wingspan, 33 feet 4 inches length (P-40F-5-CU and later), 10 
feet 7 inches high, 236 square feet wing area.  

One hundred and fifty P-40Fs were supplied to the RAF under 
Lend-Lease.  The RAF assigned them the name Kittyhawk II.  The 
Kittyhawk IIs were offset from USAAF allocations 41-13697/14599.  RAF 
serials were FL219/448.  Unfortunately, P-40Ls were also mixed in with 
this lot with no mark distinctions, so it is impossible to tell which 
planes were Fs and which were Ls by merely looking at the RAF serial 
number.  In the event, very few of these aircraft actually served with 
the RAF.  FL273 and FL369-448 were returned to the USAAF for use in 
North Africa in 1942/43.  FL230/232, 235,236, 239/240 were lost at sea 
before reaching the RAF.  FL263,270,276,280,383,305,and 307 were 
handed over to the Free French, who operated them in North Africa.  
100 were transferred to the USSR.  

The designation YP-40F was unofficially assigned to P-40F Ser No 
41-13602 used for experimental tests of the cooling system and the 
tail rudder.  The coolant system was moved aft in several different 
configurations, including inside a thickened wing-root section.  

USAAF serials of the P-40F were as follows: 

41-13600/13695 		Curtiss P-40F Warhawk 
41-13696 		Curtiss P-40F Warhawk (order cancelled) 
41-13697/14299 		Curtiss P-40F Warhawk 
41-14300/14422 		Curtiss P-40F-5-CU Warhawk 
41-14423/14599 		Curtiss P-40F-10-CU Warhawk 
41-19733/19932 		Curtiss P-40F-15-CU Warhawk 
41-19933/20044 		Curtiss P-40F-20-CU Warhawk 

A number of P-40Fs were selected at random and withdrawn from 
operational service and relegated to training duties and fitted with 
Allison V-1710-81 engines in place of their original Merlins.  These 
were redesignated P-40R-1.  At least 70 such conversions have been 
recorded.  

Sources:

  War Planes of the Second World War, Fighters, Volume Four, William Green,
  Doubleday, 1964.

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

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

  Curtiss Aircraft, 1907-1947, Peter M. Bowers, Naval Institute Press, 1979.

  The Curtiss P-40 Kittyhawk I-IV, Ray Wagner, Aircraft in Profile, 
  Volume 6, Doubleday, 1969.

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

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