From: Joseph F Baugher <jfb@ihlpl.att.com>
Subject: Number Forty in the Series--Curtiss P-40 (7 of 11)
Keywords: P-40K, back to the Allison
Organization: AT&T Bell Laboratories -  Naperville, Illinois
Date: Mon, 4 Jan 1993 17:35:52 GMT


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


Despite the success of the Merlin engine in the Warhawk, parallel 
production of the Allison-powered version continued owing to the 
limited supplies of the license-built British engine.  The P-40K 
series marked the introduction of the more powerful Allison V-1710-73 
(F4R) engine rated at 1325 hp for takeoff and 1150 hp at 11,800 feet.  
On October 28, 1941, 600 P-40Ks were ordered for Lend-Lease supply to 
China.  It was envisaged that this would be the last P-40 model to be 
built in quantity, the P-60 replacing the P-40 on the Curtiss 
production lines thereafter.  However, delays in the P-60 program 
caused the order for P-40Ks to be increased to a total of 1300 
aircraft on June 15, 1942.  

The first P-40K model rolled off the production line in August 1942.  
For some odd reason, the company model number used for the P-40K is 
unknown.  

The P-40K-1-CU and P-40K-5-CU were generally similar to 
late-production P-40Es except for the more powerful engine with an 
auto manifold pressure regulator.  The K-5 added rotary valve cooling.  
The K-1 and K-5 retained the short fuselage of the P-40E, but with the 
extra power there was a tendency to swing during takeoff and a dorsal 
fin was added to correct this problem.  The P-40K-10s and later 
production blocks had the longer fuselage introduced on the 
P-40F-5-CU.  The P-40K-15-CU was winterized.  

The maximum speed of the P-40K was 320 mph at 5000 feet and 362 mph at 
15,000 feet.  A climb to 15,000 feet took 7.5 minutes.  Range was 350 
miles with a 500-pound bomb attached.  Ferry range was 1600 miles.  
Weights were 6400 pounds empty, 8400 pounds gross, and 10,000 pounds 
maximum.  

Most of the P-40Ks served with the US forces in Asia and the Pacific 
and under Lend-Lease with the Chinese Air Force.  192 P-40K-1-CUs were 
diverted to England under Lend-Lease as Kittyhawk III.  RAF serials 
were FL875/905, FR111/115, FR210/361, and FL710/713.  Forty-two P-40Ks 
served with the RAAF under serials A-29-164/202 (P-40K-10-CU) and 
A-29-203/205 (P-40K-15-CU).  P-40Ks servicing with the RNZAF were 
NZ3045/3065, NZ3090, and NZ3099.  Nine P-40K-1-CUs served with the 
RCAF under US Army serial numbers 42-45921, 45944, 45945, 45951, 
45952, 45954, 45977, 46003, and 46004.  

The serials for the P-40Ks were as follows: 

42-9730/9929 	Curtiss P-40K-5-CU Warhawk 

42-9930/10264 	Curtiss P-40K-10-CU Warhawk 

42-10265/10429 	Curtiss P-40K-15-CU Warhawk 

42-45722/46321 	Curtiss P-40K-1-CU Warhawk 

The P-40K-1 had originally been assigned serials 42-65902/66501.  The 
P-40K-5 thru -15 were originally assigned serials 42-64502/65201.  
These were all cancelled and reassigned as shown above.  

One P-40K-10-CU, 42-10219, was fitted with an Allison V-1710-43 and 
used to develop P-40 improvements under the designation XP-40K.  
Experiments with cowling and relocated cooling systems altered the 
appearance from time to time.  One such modification produced an 
aircraft with radiators in a swollen wing center section and a slim, 
pointed nose.  

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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