National Museum of the USAF
Curtiss P-40E Warhawk
|Dimensions||37'4" by 31'9"
11.38m by 9.68m by 3.76m
|Wing area||236 square feet
21.9 square meters
|Weight|| 6350-9200 lbs
|Maximum speed||355 mph at 5,000 feet
571 km/h at 1520 meters
|Climb rate||30 feet per second
9.1 meters per second
|Service ceiling||29,000 feet
|Power plant||1 1150 hp (857 kW) Allison V-1710-39 vee-12 engine driving a three-bladed propeller|
|Armament||6 0.50 fixed
wing machine guns with 281 rounds per gun
|External stores||1 500 lb (227 kg) or 2 100 lb (45 kg) or 6 20 lb (9 kg) bombs or one 52 gallon (197 liter) drop
|Range||670 miles (1080 km) normal
900 miles (1450 km) with drop tank
|Fuel||157 gallons internal
594 liters internal
|Production||13,738 from 1940-3 at Curtiss-Wright
140 Tomahawk 1
110 Tomahawk IIA
930 Tomahawk IIB
560 Kittyhawk I
1500 Kittyhawk IA
1311 P-40F/Kittyhawk II
700 P-40L/Kittyhawk II
P-40 was produced in great variety throughout the war.
P-40B used a a 1040 hp (775 kW)
V-1710-33 engine and was armed
with two 0.50 machine guns in the cowling and two 0.30 machine guns in
The C used a 1040 hp (775 kW) V-1710-33
added two more 0.30s in the wings. Neither the B or C had any
provisions for bombs, but the C could accommodate a 52 gallon (197
liter) drop tank.
The F used a 1300 hp (969 kW) Packard V-1650-1 Merlin
engine with a two-speed supercharger. This improved the performance
somewhat at high altitude. Most of these aircraft were deployed to the
The K used a 1325 hp (988 kW) V-1710-73
engine that significantly improved performance.
The L was essentially an F with just four
0.50 machine guns and other weight saving measures, including a
reduction in fuel capacity to 120 gallons (450 liters). This failed to
improve performance significantly, and production was halted so that
the Merlin engines could be diverted to production of the P-51 Mustang.
The N used 1200 hp (895 kW) V-1710-81,
-99, or -115 engines and could carry three 500 lb (227 kg)
bombs. It had a maximum speed of 378 mph (608 km/h) at 15,000 feet
(4570 feet), but
sacrificed fuel capacity and was armed with just 4 0.50 machine guns.
The N-5 later reverted to six machine guns.
The –B and –C were known as the Tomahawk and the later models, which used a new series of Allison engines permitting a shorter nose, as the Warhawk.
Although generally regarded as outclassed by the Zero, the P-40 was the best fighter the U.S. Army Air Force had available in any quantity at the start of the Pacific War. It reflected an American design philosophy that called for heavily armed, rugged, fast fighter aircraft with self-sealing fuel tanks and armor for the pilot. The most serious defect of the earlier models was the lack of any kind of supercharger, which severely limited the high altitude performance. At the time, turbochargers were in short supply and all were reserved for bomber construction. The P-40 was much tougher than the Zero, and slightly faster at sea level, but it was also much less maneuverable at low speeds and had a poor climb rate.
The P-40 had its roots in the P-36
Hawk, which was an excellent aircraft in its day, but distinctly
obsolescent by 1939. Curtiss designer Donovan Berlin redesigned the
aircraft around the Allison V-1710 inline engine, which was just coming
into production in 1938, and the first prototype XP-37 achieved a speed
of 340 mph (550 km/h). However, the engine proved mechanically
unreliable and the cockpit had dismal visibility, and the design was
abandoned. Berlin tried again with the XP-40, doing away with the
super-turbocharging system of the XP-37 based on the Air Corps' belief
that maximum performance was needed at just 15,000 feet (4600 m). The
new aircraft was built around an improved V-1710 with ordinary
supercharging, greatly simplifying the design. The prototype flew on 14
October 1938. In spite of a disappointing top speed of 340 mph (550
km/h), the Air Corps liked its handling and dive rate. More important,
the aircraft would relatively cheap to manufacture using existing P-36
jigs and could be available relatively quickly in considerable numbers.
In 1939, the Air Corps was desperate to get new fighters quickly and in
large numbers, and more promising designs such as the P-38 were at least two years away from
The first production aircraft were delivered in early
1940 and proved able to reach 357 mph (575 km/h) at 15,000 feet (4600
m). However, this model lacked armor or self-sealing fuel tanks and was
relatively lightly armed, with two cowling 0.50 machine guns and two
wing 0.30 machine guns. Pilot armor and self-sealing tanks were added
in the P-40B, at significant cost in speed and climb rate. By the time
war broke out in the Pacific, Curtiss was producing the P-40E, which
used an improved Allison engine, gave better cockpit visibility,
improved the armament, and incorporated a number of other refinements.
Although it never became an official capability, some U.S. air units in China were improvising bomb racks for 1000lb (454 kg) bombs for the P-40 by 1943.
Because of its poor high-altitude performance, the P-40
almost always had to surrender the initiative to higher-flying
opponents. Here its ruggedness and protection were critical to allowing
it to survive the enemy's first pass. Pilots who understood its
strengths and weaknesses, such as Australian
Clive Caldwell (20.5 kills), were able to make good use of the
aircraft; but the consensus of aviation historians is that the P-40,
though it was continually improved, never became a great aircraft.
Those exported to the British were known as
About 63% of P-40 squadrons were deployed to the
Pacific, and the P-40 continued in service in China until the surrender.
Romanus and Sunderland (1953)
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