The
Curtiss P-40 Warhawk
The Curtiss P-40 Warhawk is an American single-engined, single-seat, all-metal fighter and ground-attack aircraft that first flew in 1938. The P-40 design was a modification of the previous Curtiss P-36 Hawk which reduced development time an ...
was a WWII fighter aircraft that was developed from the
P-36 Hawk
The Curtiss P-36 Hawk, also known as the Curtiss Hawk Model 75, is an American-designed and built fighter aircraft of the 1930s and 40s. A contemporary of the Hawker Hurricane and Messerschmitt Bf 109, it was one of the first of a new generatio ...
, via the P-37. Many variants were built, some in large numbers, under names including the Hawk, Tomahawk and Kittyhawk.
Allison-engined Model 75
XP-37
![Curtiss XP-37 060908-F-1234P-010](https://upload.wikimedia.org/wikipedia/commons/a/a2/Curtiss_XP-37_060908-F-1234P-010.jpg)
In early
1937, after realizing the Hawk 75 was inferior to more modern European designs, the
USAAC
The United States Army Air Corps (USAAC) was the aerial warfare service component of the United States Army between 1926 and 1941. After World War I, as early aviation became an increasingly important part of modern warfare, a philosophical r ...
ordered one P-36 to be modified with an
Allison V-1710 inline engine. The prototype Hawk was fitted with a turbo-supercharged 1,150 hp (860 kW) Allison V-1710-11 engine as the XP-37 (company designation Model 75I). The cockpit was moved back towards the tail to make room for the massive supercharger, and the engine was cooled by two radiators on either side of the nose. Armament was one .30
M1919 Browning MG and one .50
M2 Browning MG mounted in the nose. The XP-37 was plagued with supercharger and visibility problems.
YP-37
![Curtiss YP-37 SN 38-472 060908-F-1234P-012](https://upload.wikimedia.org/wikipedia/commons/6/69/Curtiss_YP-37_SN_38-472_060908-F-1234P-012.jpg)
A further 13 Model 75Is were ordered in
1938 under the designation YP-37. These differed from the XP-37 in having a V-1710-21 with a more reliable supercharger and an extended nose. The project was cancelled after continued supercharger and visibility problems.
XP-40
![Curtiss XP-40 in flight, circa in 1939](https://upload.wikimedia.org/wikipedia/commons/1/1a/Curtiss_XP-40_in_flight%2C_circa_in_1939.jpg)
In 1937, the 10th P-36A was fitted with a 1,150 hp (860 kW) V-1710-19. Unlike the Model 75I, the resulting XP-40 (Model 75P) did not have a turbo-supercharger, thus the cockpit was not moved back, and the radiator was moved to the ventral position. Later the landing gear was redesigned and the radiator was moved under the nose. Armament was two .50 M2 Brownings mounted in the nose.
The new engine conferred a 50 mph speed advantage over the already popular Hawk, and export orders from England and France came in quickly. In April 1939, the
United States Army Air Corps
The United States Army Air Corps (USAAC) was the aerial warfare service component of the United States Army between 1926 and 1941. After World War I, as early aviation became an increasingly important part of modern warfare, a philosophical r ...
also put in a domestic order for 524 Model 75Ps, which was the largest single order for a US fighter aircraft at the time.
Model 81
P-40
![Curtiss P-40 (SN 39-156, first production P-40) 061019-F-1234P-026](https://upload.wikimedia.org/wikipedia/commons/3/32/Curtiss_P-40_%28SN_39-156%2C_first_production_P-40%29_061019-F-1234P-026.jpg)
The production P-40 (Model 81A) were nearly identical to the XP-40, but was built with a 1,040 hp (780 kW) V-1710-33s and one .30 M1919 Browning in each wing. The company designation was changed to Model 81 due to the extensive changes from the standard Model 75. France, who was a large operator of the P-36, was interested in this fighter and ordered 140 aircraft as Hawk 81A-1s. However, following the 1940
French Armistice the
Royal Air Force
The Royal Air Force (RAF) is the United Kingdom's air and space force. It was formed towards the end of the First World War on 1 April 1918, becoming the first independent air force in the world, by regrouping the Royal Flying Corps (RFC) an ...
acquired these aircraft as Tomahawk Mk.Is. This variant was not considered combat-ready, as they lacked heavy armament and armor, but as there was a shortage of decent fighter aircraft after the
Battle of Britain
The Battle of Britain, also known as the Air Battle for England (german: die Luftschlacht um England), was a military campaign of the Second World War, in which the Royal Air Force (RAF) and the Fleet Air Arm (FAA) of the Royal Navy defende ...
, the RAF pressed these into service for use in
North Africa
North Africa, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in ...
anyway.
Sub-variants and modifications
* P-40, 524 aircraft ordered, only 200 produced.
* P-40A, one P-40 that was fitted with cameras for
photo reconnaissance
Aerial reconnaissance is reconnaissance for a military or strategic purpose that is conducted using reconnaissance aircraft. The role of reconnaissance can fulfil a variety of requirements including artillery spotting, the collection of ima ...
missions.
* P-40G, 44 P-40s that were fitted with four-gun P-40B/C wings, the first of which being unofficially designated XP-40G.
* Hawk 81A-1, export version, 140 aircraft ordered by the
Armée de L'air
The French Air and Space Force (AAE) (french: Armée de l'air et de l'espace, ) is the air and space force of the French Armed Forces. It was the first military aviation force in history, formed in 1909 as the , a service arm of the French Arm ...
, but were delivered to the
Royal Air Force
The Royal Air Force (RAF) is the United Kingdom's air and space force. It was formed towards the end of the First World War on 1 April 1918, becoming the first independent air force in the world, by regrouping the Royal Flying Corps (RFC) an ...
as Tomahawk Mk.Is. A number of minor changes were made, including replacing the .30 Browning MGs in the wings with .303 Browning MGs, which was done on most Tomahawk marks.
P-40B
Of the remaining 324 aircraft of the initial order, 131 were built as P-40Bs.
Though strongly built, the first P-40 variant was poorly protected and lacked armor and self sealing tanks. This was partly rectified with the P-40B, which had additional armor behind the cockpit, but fuel system and control line vulnerability remained a problem to some extent with all Tomahawk types. The P-40B also had an additional .30 MG in each wing.
Sub-variants
* P-40B, 131 aircraft built.
* Hawk 81A-2, export version, 110 aircraft produced for the RAF as Tomahawk Mk.IIs and Mk.IIAs, the latter equipped with .303 Brownings.
P-40C
![P-40C 29th Fighter Squadron May 1942](https://upload.wikimedia.org/wikipedia/commons/f/f7/P-40C_29th_Fighter_Squadron_May_1942.jpg)
The last 193 aircraft of the original P-40 order were completed as P-40Cs.
In an attempt to further rectify the problem of poor protection, the P-40C was given
self-sealing fuel tank
A self-sealing fuel tank is a type of fuel tank, typically used in aircraft fuel tanks or fuel bladders, that prevents them from leaking fuel and igniting after being damaged.
Typical self-sealing tanks have multiple layers of rubber and reinfo ...
s. The obsolete SCR-283 radio of the earlier P-40s was replaced with an
SCR-274N and provisions were made for a 52 gal
drop tank
In aviation, a drop tank (external tank, wing tank or belly tank) is used to describe auxiliary fuel tanks externally carried by aircraft. A drop tank is expendable and often capable of being jettisoned. External tanks are commonplace on modern ...
.
The latter change increased the combat radius dramatically, and was a standard feature in all subsequent P-40s.
Sub-variants and modifications
* P-40C, 193 aircraft built.
* Hawk 81A-3, export version, 930 aircraft built for the RAF as Tomahawk Mk.IIBs, many of which were diverted to other allies.
* Hawk 81A-2/3, export version, 100 Hawk 81A-3 aircraft were diverted from an RAF order and delivered to the
Nationalist Chinese Air Force for use by the
American Volunteer Group. Although they were officially Hawk 81A-3s, they lacked the provisions for a drop tank.
Model 87
P-40D
![P-40d 02 172](https://upload.wikimedia.org/wikipedia/commons/b/b7/P-40d_02_172.jpg)
Soon after P-40 production started, Curtiss began development of its intended successor, the
XP-46. This aircraft was based on the P-40, but was an almost entirely different aircraft. While retaining the rear fuselage of the P-40, the XP-46 had a new wing with wider track landing gear. The nose was redesigned too, as it housed a new 1,150 hp (860 kW) V-1710-39 engine. This "F-series" engine differed from the "C-series" engine of the Model 81 in having a more compact external spur gear-type
reduction gear box
An epicyclic gear train (also known as a planetary gearset) consists of two gears mounted so that the center of one gear revolves around the center of the other. A carrier connects the centers of the two gears and rotates the planet and sun gea ...
. The production version of the P-46 was to have four .30 MGs in each wing and two .50 MGs in the nose for a total of ten guns. This would have been the heaviest armament for a US fighter at the time. Both the USAAF and RAF placed orders for this aircraft, with the latter naming it "Kittyhawk".
Due to delays in the P-46 program, the USAAF asked Curtiss to prioritize development of an improved P-40. Curtiss did so, and reworked the P-40 to accommodate the V-1710-39 of the XP-46. The resulting P-40D (Model 87A) had a shorter nose with a larger radiator, four .50 Brownings in place of the .30 units, a revised windscreen, and provisions for two
20 mm cannons (one in each wing, never used). The nose guns were deleted as there wasn't room for them in the final design.
Upon testing both the P-40D and XP-46 prototypes, the USAAF found that the XP-46 offered no significant improvement over the P-40C, and was inferior to the P-40D. Both the USAAF and RAF cancelled their orders for the P-46 and the name "Kittyhawk" was given to the P-40D.
Sub-variants
* P-40D, 2 aircraft built for testing purposes, both were later modified into the prototypes of subsequent variants.
* P-40D-1, 21 aircraft built for service with the USAAF.
* Hawk 87A-1, export version, 560 were built for the RAF as Kittyhawk Mk.Is. The first 20 of these aircraft were built with the standard four guns, but the rest had six, making them almost identical to the later Mk.IA. Some were diverted to other allies.
P-40E
![Curtiss Kittyhawk Mk1A AN1096502](https://upload.wikimedia.org/wikipedia/commons/b/b5/Curtiss_Kittyhawk_Mk1A_AN1096502.jpg)
Starting with the 24th Model 87, an additional .50 MG was added to each wing and the carburetor intake was moved forward 6 in. Although these changes were relatively minor, this new variant was given the designation P-40E.
When the P-40D and E went into service, several problems were discovered. When maneuvering in high G turns the guns would often jam due to the way the ammunition was stored. Another problem was that engine and trim management were both somewhat complex and taxing with earlier P-40's required strong rudder pressure to offset engine torque and frequent trim adjustments were needed during rapid speed changes. Both these problems were remedied sometime late in production by enlarging the vertical stabilizer and changing how the ammunition was stored.
P-40's were more a powerful, faster-flying aircraft than the primary and advanced trainers most pre-war and early-war Allied pilots were familiar with, and transition training was often inadequate or neglected altogether in the early years of the war. The landing gear was also more narrow and not as strong as in fixed gear aircraft (like the Gladiator) or on some other retractable gear fighters such as the Hurricane. As a result novice pilots had a hard time adjusting to the new fighter and there were many accidents on landing and takeoff in the early years of the war, with both Tomahawk and Kittyhawk types. Therefore, two P-40Es were fitted with a second seat to be used as
trainer aircraft
A trainer is a class of aircraft designed specifically to facilitate flight training of pilots and aircrews. The use of a dedicated trainer aircraft with additional safety features—such as tandem flight controls, forgiving flight characteristi ...
under the designation P-40ES. With these aircraft and improved training techniques these problems subsided.
Sub-variants and modifications
* Prototype P-40E, the second P-40D fitted with a six-gun wing.
* P-40E, 820 aircraft built. Somewhere along the production line flared "fishtail" exhaust stacks appeared, and an unknown number of late production aircraft had larger vertical stabilizers.
* P-40ES, two aircraft modified into two-seat
trainer aircraft
A trainer is a class of aircraft designed specifically to facilitate flight training of pilots and aircrews. The use of a dedicated trainer aircraft with additional safety features—such as tandem flight controls, forgiving flight characteristi ...
.
* P-40EF, a number of P-40Es and Ks modified by the
Soviet Air Force
The Soviet Air Forces ( rus, Военно-воздушные силы, r=Voyenno-vozdushnyye sily, VVS; literally "Military Air Forces") were one of the air forces of the Soviet Union. The other was the Soviet Air Defence Forces. The Air Forces ...
as two seat photo reconnaissance aircraft.
The "EF" designation was unofficially given to the aircraft by the Soviets, with the F standing for "Foto", the Russian word for photo.
* Hawk 87A-2, export version, the RAF received 1,500 Kittyhawk Mk.IAs under
Lend-Lease. These were given the USAAF designation P-40E-1. Some were diverted to other allies.
P-40J
The main problem with the P-40 was its effective altitude ceiling of about 12,000 feet. Above that altitude the single-stage Allison V-1710 engine started to perform poorly. As a result, unless combat was taking place at low altitude, P-40 pilots often faced attack from above in the opening stages of an interception, a chronic problem which cost many lives. In response, Curtiss proposed the P-40J, which was basically a P-40E with a
turbo-supercharged V-1710. Although a good idea on paper, there were many problems with fitting a turbo-supercharged V-1710 into the P-40. One of the main problems was the size of the turbocharger, which would not fit in the standard P-40 airframe. On top of that the intended engines were reserved for
P-38
The Lockheed P-38 Lightning is an American single-seat, twin piston-engined fighter aircraft that was used during World War II. Developed for the United States Army Air Corps by the Lockheed Corporation, the P-38 incorporated a distinctive twi ...
production. In May 1942 the project was cancelled without anything being built.
P-40F
![Warhawk Curtiss P-40F (16140386735)](https://upload.wikimedia.org/wikipedia/commons/3/39/Warhawk_Curtiss_P-40F_%2816140386735%29.jpg)
Another solution to the high altitude performance problem was to fit the P-40 with a supercharged
Rolls-Royce Merlin
The Rolls-Royce Merlin is a British liquid-cooled V-12 piston aero engine of 27-litres (1,650 cu in) capacity. Rolls-Royce designed the engine and first ran it in 1933 as a private venture. Initially known as the PV-12, it was late ...
engine. This idea came from the British, as they noticed that their Allison powered Kittyhawks and
Mustangs
The mustang is a free-roaming horse of the Western United States, descended from horses brought to the Americas by the Spanish. Mustangs are often referred to as wild horses, but because they are descended from once-domesticated animals, they ...
had poor performance at high altitudes, while their own Merlin powered
Hurricanes
A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depend ...
and
Spitfires
The Supermarine Spitfire is a British single-seat fighter aircraft used by the Royal Air Force and other Allied countries before, during, and after World War II. Many variants of the Spitfire were built, from the Mk 1 to the Rolls-Royce Grif ...
did not have the same problems. Curtiss fitted the second P-40D with a 1,300 hp (969 kW) Merlin 28. Production aircraft had the American-made 1,390 hp (1,040 kW)
Packard V-1650-1 Merlin. The resulting P-40F (Model 87B) was the first variant to carry the "Warhawk" name.
Along with the added power of the Merlin engine came a decrease in directional stability. Curtiss attempted to fix this by fitting a dorsal fillet to the tail of a single P-40F; however, this was not adopted into production. Starting with the P-40F-5, the tail was lengthened by about 20 in.
Although the P-40F was superior to the Allison powered P-40s, there was a shortage of Merlin engines due to the vast number of aircraft that used them. Parts for these engines were becoming scarce, and maintenance became an issue. As a result, at least 70 P-40Fs were re-engined with V-1710-81s of 1,360 hp.
These aircraft became known as P-40R-1s.
Sub-variants and modifications
*XP-40F, the second P-40D fitted with a 1,300 hp Rolls-Royce Merlin 28.
*P-40F, (also P-40F-1) the first production batch of 699 aircraft with American-made Packard V-1650-1 engines.
*P-40F-5, 123 aircraft with an extended fuselage to counteract extra torque from the Merlin.
*P-40F-10, 177 aircraft with manually-operated cowl flaps replacing the electronic units of the earlier variants.
*P-40F-15, 200 aircraft with winterized equipment.
*P-40F-20, 112 aircraft with a revised cockpit oxygen flow system.
*YP-40F, the third production P-40F used for streamlining tests.
*P-40R-1, at least 70 P-40Fs that were fitted with V-1710-81 engines due to the shortage of Merlins.
*Hawk 87B-2, export version, 150 built for the RAF under Lend-Lease as Kittyhawk Mk.IIs.
P-40K
![Curtiss P-40K Kittyhawk](https://upload.wikimedia.org/wikipedia/commons/f/fc/Curtiss_P-40K_Kittyhawk.jpg)
The P-40K was intended to be the last P-40 production variant before replacement by the
P-60, and only 600 were ordered by the USAAF to supply to China.
However, with the cancellation of the P-60 the
attack on Pearl Harbor
The attack on Pearl HarborAlso known as the Battle of Pearl Harbor was a surprise military strike by the Imperial Japanese Navy Air Service upon the United States against the naval base at Pearl Harbor in Honolulu, Territory of Hawaii ...
led to this order being increased to 1,300 aircraft. A continuation of the Allison-powered Warhawk, the K was similar to the P-40E, but was powered by a 1,325 hp V-1710-73. It also featured improved machine gun ammunition storage reducing gun stoppages. These were the heaviest P-40 variants, but the extra horsepower on the P-40K gave it good performance particularly at low altitude (noticeably better than the P-40E).
As with the P-40F, the increase in power led to decreased directional stability, but Curtiss predicted this and incorporated an enlarged vertical stabilizer to early P-40Ks. On the K-10 sub-variant onward, this was replaced with the lengthened tail of the P-40F-5. This feature was standard on all subsequent Warhawks.
Sub-variants and modifications
*P-40K-1, the first 600 aircraft ordered for Lend-Lease to China but were taken over by the USAAF and RAF after
Pearl Harbor
Pearl Harbor is an American lagoon harbor on the island of Oahu, Hawaii, west of Honolulu. It was often visited by the Naval fleet of the United States, before it was acquired from the Hawaiian Kingdom by the U.S. with the signing of the R ...
.
*P-40K-5, 200 aircraft with rotary valve cooling.
*P-40K-10, 335 aircraft with the long tail of the P-40F-5.
*P-40K-15, 165 aircraft with winterized equipment.
*TP-40K, one P-40K modified as a two-seat trainer.
*XP-40K, one P-40K-10 with a V-1710-43 used to test wing root radiators.
*Kittyhawk Mk.III, 351 P-40Ks built for the RAF under Lend-Lease as Kittyhawk Mk.IIIs, about half which were diverted to other allies.
P-40L
A continued development of the Merlin powered Warhawk, the P-40L was a lightened version of the P-40F. Many weight saving changes were made to the aircraft, including removal of armor plating and reduction of rounds per gun. On the P-40L-5, weight was further reduced by removing two of the guns and reducing the internal fuel capacity from 157 gal. to 120 gal.
As with the P-40F, at least 53 P-40Ls were re-engined with V-1710-81s.
Sub-variants and modifications
*P-40L-1, 50 aircraft built similar to the P-40F-5 but with some equipment removed.
*P-40L-5, 220 aircraft with two wing guns removed and reduced fuel capacity.
*P-40L-10, 148 aircraft with electric aileron trim tabs and revised engine controls.
*P-40L-15, 112 aircraft with revised carburetor filters and signal lights.
*P-40L-20, 170 aircraft with radio and electrical system changes and provisions for an incendiary grenade.
*P-40L-25, 567 aircraft ordered, cancelled and never built.
*P-40L-30, 60 aircraft ordered, cancelled and never built.
*P-40R-2, at least 53 aircraft re-engined with V-1710-81s.
*Hawk 87B-3, export version, 100 built for the RAF as Kittyhawk Mk.IIs, and a further 160 as Kittyhawk Mk.IIIs. Most of these had the three gun wings of the P-40F.
P-40M
![P-40M in Finnish markings in 1944](https://upload.wikimedia.org/wikipedia/commons/4/4a/P-40M_in_Finnish_markings_in_1944.jpg)
Due to the shortage of Merlins, development of the Allison powered Warhawk was again continued. The P-40K airframe was given a 1,360 hp V-1710-81 with a cooling grill forward of the exhaust stubs.
The P-40M was supposed to be a purely export variant of the K, although many ended up in USAAF units. In RAF service the aircraft was named Kittyhawk Mk.III, the same as the P-40K, which can cause some confusion.
Sub-variants and modifications
* P-40M-1, the first 60 aircraft.
* P-40M-5, 260 aircraft with carburetor air filter and aileron improvements.
* P-40M-10, 280 aircraft with changes to the fuel system and undercarriage warning system.
* TP-40M, a small number of aircraft converted to two-seat trainers.
* Kittyhawk Mk.III, 466 aircraft built for the RAF,
RAAF
"Through Adversity to the Stars"
, colours =
, colours_label =
, march =
, mascot =
, anniversaries = RAAF Anniversary Commemoration ...
, and
RNZAF
The Royal New Zealand Air Force (RNZAF) ( mi, Te Tauaarangi o Aotearoa, "The Warriors of the Sky of New Zealand"; previously ', "War Party of the Blue") is the aerial service branch of the New Zealand Defence Force. It was formed from New Zeal ...
.
Many were diverted to other allies.
P-40N
![Cavanaugh Flight Museum-2008-10-29-052 (4269836337)](https://upload.wikimedia.org/wikipedia/commons/9/96/Cavanaugh_Flight_Museum-2008-10-29-052_%284269836337%29.jpg)
The P-40N was the most produced variant of the Warhawk, with 5220 aircraft built.
In an attempt to increase performance, Curtiss lightened the P-40M by introducing a lightweight structure, lighter, smaller-diameter undercarriage wheels, removing two of the guns, and installing aluminum radiators and oil coolers. Head armor was also re-introduced. With these changes, the P-40N-1 (Model 87V) was the fastest production Warhawk, reaching a speed of 378 mph below 12,000 feet.
Starting with the P-40N-5 (Model 87W), the canopy was redesigned to give the pilot a better field of vision. This variant also reverted to the six gun wing and one rack was added to each wing, these could carry either bombs or drop tanks.
A more powerful V-1710-99 engine was introduced on the N-20, and a further improved V-1710-115 was introduced on the N-40. Curtiss attempted to further improve visibility and fitted one P-40N with a bubble canopy; this feature never made it to production.
Sub-variants and modifications
*P-40N-1, the first 400 aircraft with a lighter structure, 4 wing-mounted MGs, smaller diameter undercarriage tires, aluminum radiators and oil coolers, and head armor.
*
![Curtiss P-40N NL-1011N (5433030466)](https://upload.wikimedia.org/wikipedia/commons/0/06/Curtiss_P-40N_NL-1011N_%285433030466%29.jpg)
P-40N-5, 1,100 aircraft with a revised cockpit canopy, 6 wing-mounted MGs, and wing racks for bombs or drop tanks.
*P-40N-6, P-40N-5s modified in the field with fuselage mounted cameras for reconnaissance.
*P-40N-10, 100 winterized aircraft with 4 wing-mounted MGs.
*P-40N-15, 377 aircraft with 6 wing mounted MGs, a relocated battery,
and larger wing fuel tanks.
*P-40N-16, P-40N-15s modified for reconnaissance.
*P-40N-20, 1,523 aircraft with a V-1710-99.
*P-40N-25, 500 aircraft with a revised instrument panel and non-metal fuel tanks.
*P-40N-26, P-40N-25s modified for reconnaissance.
*P-40N-30, 500 aircraft with valve and electrical system changes.
*P-40N-35, 500 aircraft with system changes and a new radio
*P-40N-40, 220 aircraft with a 1,360 hp V-1710-115 engine, metal covered ailerons, improved fuel tanks, new radio and oxygen system, and flame-dampening exhaust stacks. An order for 780 aircraft was cancelled.
*TP-40N, 30 various P-40Ns modified or factory built with a second seat for training purposes.
Other known designations included RP-40N-26 (TP-40N-25) and P-40N-31 (TP-40N-30).
*XP-40N (P-40XN), one P-40N aircraft modified with a
bubble canopy
A bubble canopy is an aircraft canopy constructed without bracing, for the purpose of providing a wider unobstructed field of view to the pilot, often providing 360° all-round visibility.
The designs of bubble canopies can drastically vary; s ...
. Designation was not official. One source states that this aircraft was converted from a P-40N-25 and later converted into the third XP-40Q.
However, another source states that the XP-40N was converted from a P-40K-1 and later converted into the second XP-40Q, but this is unlikely as photographic evidence shows that the XP-40N had the long tail that first appeared on the P-40K-10.
*Hawk 87V and 87W, export versions, 586 built for the RAF as Kittyhawk Mk.IVs. Some were diverted to other allies.
P-40P
The P-40P was a planned variant of the P-40N with a Merlin engine. The project was cancelled due to a shortage of Merlins and the aircraft were delivered as P-40Ns.
P-40Q
![Warhawk Curtiss XP-40Q 42-9987 (16140403045)](https://upload.wikimedia.org/wikipedia/commons/e/e7/Warhawk_Curtiss_XP-40Q_42-9987_%2816140403045%29.jpg)
In 1944, Curtiss attempted to bring the Warhawk to the standards of more modern fighters such as the
North American P-51 Mustang
The North American Aviation P-51 Mustang is an American long-range, single-seat fighter and fighter-bomber used during World War II and the Korean War, among other conflicts. The Mustang was designed in April 1940 by a team headed by James ...
. To do so, Curtiss installed a 1,425 hp
water injected V-1710-121 into the Hawk 87 airframe. The resulting aircraft became the fastest P-40 model at 422 mph.
Even with these modifications, the P-40Q (Model 87X) was still inferior to modern fighters and the project was cancelled.
Sub-variants
*
![Curtiss P-40K](https://upload.wikimedia.org/wikipedia/commons/a/a2/Curtiss_P-40K.jpg)
XP-40Q-1, originally a P-40K-10, this prototype bore a resemblance to the XP-40K, having similar wing root radiators. Apart from this, the aircraft had a lengthened nose and four-bladed propeller.
Armament consisted of four .50 Brownings, these were carried on all XP-40Q prototypes.
* XP-40Q-2, initial prototype after extensive modifications. The radiator intake was relocated to its original position under the nose, but was more streamlined. A bubble canopy similar to the one on the XP-40N was installed. The aircraft was originally flown with round wingtips, but these were later clipped by one foot, giving them a square appearance.
*XP-40Q-2A, the first P-40K-1 was converted into the second XP-40Q. This aircraft was similar to the XP-40Q-2, but with minor changes. One source states that this aircraft was converted from the XP-40N.
* XP-40Q-3, P-40N-25 was modified into the third prototype. This aircraft was almost identical to the XP-40Q-2 with the exception of a more streamlined canopy. One source states that this aircraft was converted from the XP-40N.
* P-40Q, proposed production version with either six .50 guns or four
20 mm
20 mm caliber is a specific size of popular autocannon ammunition. It is typically used to distinguish smaller-caliber weapons, commonly called "guns", from larger-caliber "cannons" (e.g. machine gun vs. autocannon). All 20 mm cartridges h ...
cannons. Never built.
Twin P-40
A single photo exists of a P-40 with two Merlin engines mounted on top of the wings over the landing gear. The apparent
serial number, 41-13456, belongs to a P-40C,
however, the canopy is from an early Hawk 87.
References
Notes
Bibliography
*
*
*
{{P-40 Warhawk family
P-40 variants
World War II Chinese fighter aircraft
World War II Soviet fighter aircraft