Warhawk, Kittyhawk III
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
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. This
engine had an automatic boost control.
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
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 Allison engine. 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
that was 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/FL905, FR111/FR115, FR210/FR361, and FL710/FL713. The
first examples were delivered to the Middle East in late 1942.
Forty-two P-40Ks served with
the RAAF under serials A29-164/202 (P-40K-10-CU) and A29-203/205
(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.
25 P-40Ks were diverted to Brazil
The serials for the P-40Ks were
42-9730/9929 Curtiss P-40K-5-CU
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 some proposed
P-40 improvements under the designation XP-40K. Experiments
with cowling and relocated cooling systems altered the appearance
of the aircraft from time to time. One such modification produced
an aircraft with radiators in a swollen wing center section
and a slim, pointed nose.
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 Tomahawk, Ray
Wagner, Aircraft in Profile, Volume 2, Doubleday, 1965.