Curtiss P-40 Warhawk
The Curtiss P-40 Warhawk was an American single-seat, single-engine, all-metal fighter-bomber that first took to the skies in 1938.
Developed as a modification of the earlier Curtiss P-36 Hawk, the P-40 retained much of its predecessor’s airframe but incorporated a more powerful inline engine, enabling rapid development and swift introduction into active service.
Produced by Curtiss-Wright Corporation at its Buffalo, New York facility, the Warhawk became the third most-manufactured American fighter of World War II—behind only the North American P-51 Mustang and Republic P-47 Thunderbolt.
By the time production ceased in November 1944, 13,738 P-40s had been built.
Initially designated Warhawk by the United States Army Air Corps, the name became official across all models after mid-1941 with the establishment of the US Army Air Forces (USAAF).
Among its Allies, however, naming conventions varied.
The British Commonwealth and Soviet air forces referred to early variants (P-40, P-40B, P-40C) as Tomahawk, while later versions (P-40D onward) were known as Kittyhawk.
The aircraft saw its first combat in June 1941 with Royal Air Force squadrons in the Middle East and North Africa.
No. 112 Squadron RAF was among the first to field the Tomahawk in combat and became widely recognised for introducing the now-iconic “shark mouth” nose art, inspired by Luftwaffe Bf 110 fighters.
Due to its Allison V-1710 engine’s lack of a two-speed supercharger, the P-40 was outperformed at high altitude by German aircraft such as the Bf 109 and Fw 190.
As a result, it was seldom used over Northwest Europe.
Nevertheless, from 1941 to 1944, it was a vital asset in other theatres including North Africa, the South-west Pacific, and China.
It also played key roles in campaigns across the Middle East, South-east Asia, Eastern Europe, Alaska, and Italy, where its high-altitude limitations were less critical.
In these regions, the P-40 was employed effectively as a fighter, bomber escort, and fighter-bomber.
Though often overshadowed by more advanced designs and sometimes unfairly labelled as mediocre post-war, modern analyses of operational records tell a different story.
The P-40 frequently performed admirably in air superiority roles, enduring losses but also achieving significant success.
More than 200 Allied pilots became aces while flying the P-40, including at least 20 double aces.
These pilots hailed from the United States, United Kingdom, Australia, New Zealand, Canada, South Africa, and the Soviet Union, excelling particularly in the North African, Chinese, South-east Asian, and South-west Pacific theatres.
The P-40’s rugged construction, affordability, and reliability ensured its continued use even after it was technically outclassed.
It remained in service throughout the war as a dependable ground-attack platform long after its prime in the fighter role had passed.
During World War II, the Curtiss P-40 Warhawk served extensively across a wide range of operational theatres.
Its versatility, durability, and reliability made it a key asset for Allied forces, particularly in regions where its high-altitude limitations were less of a factor.
Here’s a breakdown of the major theatres where the P-40 saw combat:
North Africa and the Middle East
The P-40 played a prominent role with the Desert Air Force during the North African Campaign (1941–1943).
Pilots from the RAF, RAAF, SAAF, and USAAF flew the aircraft in operations across Libya, Egypt, and Tunisia.
This theatre saw the first major combat deployment of the Tomahawk and later Kittyhawk variants.
China-Burma-India (CBI) Theatre
The P-40 gained legendary status with the American Volunteer Group—the “Flying Tigers”—who defended China from Japanese incursions before the US formally entered the war.
Throughout the conflict, the USAAF continued to use P-40s in the region, where their ruggedness proved ideal for harsh terrain and airfield conditions.
South-west Pacific
In New Guinea, the Philippines, and surrounding islands, P-40s were employed by Australian and American forces.
The aircraft often operated from rough forward airstrips, defending against Japanese air and ground assaults and escorting bombers over dense jungle terrain.
South-east Asia
Commonwealth forces deployed the P-40 in the defence of British Malaya, Burma, and India.
It served as both a fighter and fighter-bomber, participating in defensive actions and later Allied offensives across the region.
Soviet Union (Eastern Front)
The Soviet Air Force received several hundred P-40s through the Lend-Lease program.
Though not as highly regarded as some Soviet-built types, it served effectively in a ground attack and air defence capacity, especially in secondary fronts.
Mediterranean and Italian Campaigns
P-40s supported Allied operations during the invasion of Sicily and the campaign up the Italian Peninsula.
Their role largely shifted toward close air support and tactical bombing missions as newer fighters replaced them in air superiority roles.
Alaska and Aleutian Islands
During the Aleutian Campaign, USAAF P-40s engaged Japanese forces occupying parts of the island chain.
The harsh Arctic environment tested the aircraft’s durability, and it performed admirably in difficult weather conditions.
Variants and development stages
Curtiss XP-40 & P-40
XP-40 Prototype Origins
Designation
Curtiss XP-40 (Model 75P)
Development Date
Ordered July 1937
Conversion Basis
The XP-40 was derived from the tenth production P-36A airframe, modified to accommodate an inline engine.
Engine Configuration
Powered by the new Allison V-1710-19 liquid-cooled V-12 engine, replacing the original radial powerplant.
First Flight
October 1938
Cooling System Design
The prototype initially featured a radiator positioned beneath the rear fuselage, which led to suboptimal cooling performance.
This design was soon revised, relocating the radiator beneath the engine, improving aerodynamics and engine efficiency.
P-40
First Production Variant Model Designation
Curtiss Model 81A-1
Service Name
P-40 Warhawk
Production Quantity
199 units
Role
Fighter aircraft
Overview
The P-40 retained the XP-40’s streamlined design and engine configuration.
It became the foundation for an extensive lineage of Warhawk variants that served Allied air forces throughout World War II.
Curtiss P-40A and Early Variants
P-40A
Photo-Reconnaissance Prototype
Designation
P-40A
Role
Prototype photo-reconnaissance aircraft
Overview
A single P-40 airframe was modified to carry a camera installation in the rear fuselage for evaluation purposes.
This aircraft was retrospectively designated as the P-40A and did not enter series production.
Evolution of Early P-40 Variants
P-40B / Tomahawk IIA
Armament Upgrade
Introduced wing-mounted .30 in (7.62 mm) or .303 in (7.7 mm) machine guns depending on operator specification.
Protection Enhancements
Incorporated partial fuel system protection, improving survivability in combat.
Performance Note
The additional weight modestly affected overall manoeuvrability and climb rate.
P-40C / Tomahawk IIB
Expanded Capability
Equipped with underbelly drop tank and bomb shackles, enhancing range and ground attack utility.
Safety Improvements
Included self-sealing fuel tanks and structural revisions for operational resilience.
Performance Trade-off
While more versatile, increased weight continued to reduce speed and rate of climb.
Note
All early Warhawk variants—including the B and C models—were characterised by a relatively low power-to-weight ratio when compared to contemporary frontline fighters.
P-40D / Kittyhawk Mk I
Production Quantity
Fewer than 50 units produced.
Powerplant Upgrade
Fitted with a larger Allison V-1710 engine, requiring an enlarged chin air-scoop to manage additional cooling demands.
Airframe Modifications
Slightly narrowed fuselage for aerodynamic refinement.
Redesigned cockpit canopy and improved crew ergonomics.
Armament Revision
Eliminated nose-mounted .50 in (12.7 mm) guns in favour of two .50 in guns in each wing, totalling four.
P-40E / Kittyhawk Mk IA
Armament Increase
Retained P-40D’s configuration but added an extra .50 in gun per wing, bringing the total to six.
Payload Capability
Some aircraft featured small underwing bomb racks for tactical flexibility.
Combat Deployment
Widely used in early 1942, particularly by units transitioning from earlier P-40B/C models.
Played a pivotal role in air combat operations across various theatres:
China
Replaced AVG aircraft as the primary fighter of U.S. squadrons.
Australia
Engaged Japanese forces at Milne Bay, marking a key Allied victory.
New Zealand
Operated as the primary air-to-air combat fighter during the war.
North Africa
Flown by RAF/Commonwealth forces as Kittyhawk IA, forming the backbone of tactical fighter units.
Curtiss P-40F, P-40L, P-40G, and P-40K
P-40F / Kittyhawk Mk II
Engine Type
Packard-built V-1650 Merlin, replacing the standard Allison engine.
Design Characteristics
Elimination of the carburettor scoop on top of the nose due to revised engine layout.
Optimised for high-altitude performance, making it superior to earlier Allison-powered variants.
Operational Service
Extensively employed by U.S. fighter groups in the Mediterranean Theater.
Supplied to the Commonwealth under Lend-Lease as the Kittyhawk Mk II.
330 aircraft delivered to the RAF, with the first 230 units informally designated Kittyhawk Mk IIA.
P-40L / Kittyhawk Mk II
Derivative of the P-40F, sharing the same Merlin powerplant.
Structural Modifications
Some aircraft featured a stretched fuselage or a fillet ahead of the vertical stabiliser to counteract increased torque.
Often produced in a lightened configuration, with reduced armament and equipment for improved agility.
P-40G / RP-40G
Conversion
43 standard P-40s modified with Tomahawk Mk IIA wings for evaluation and utility roles.
Distribution
16 aircraft delivered to the Soviet Union under aid agreements.
Remaining units allocated to the U.S. Army Air Forces.
Re-designation
Later classified as RP-40G, indicating restricted or limited operational roles.
P-40K / Kittyhawk Mk III
Configuration
An Allison-powered alternative to the P-40L, retaining classic features:
Top-mounted carburettor scoop
Allison nose radiator intake
Cowl flaps
Fillet between fuselage and vertical stabilizer for stability
Operational Service
Delivered to Commonwealth air forces as the Kittyhawk Mk III.
Widely used by U.S. units in the China-Burma-India (CBI) Theater, where rugged reliability was a key advantage.
Curtiss P-40M, P-40N, and P-40P
P-40M / Kittyhawk Mk III
Engine
Allison V-1710-81, offering enhanced altitude performance over earlier Allison variants.
Design Features
Shared general configuration with the P-40K.
Featured a stretched fuselage, similar to that of the Merlin-powered P-40L, improving stability and handling.
Easily identified by two small air scoops located forward of the exhaust stacks.
Operational Use
Supplied extensively to Allied nations, particularly the United Kingdom and Soviet Union.
A number of units retained by the United States for use in advanced pilot training.
Distributed to Commonwealth forces under the designation Kittyhawk Mk III.
P-40N / Kittyhawk Mk IV
Production Period
1943–1944
Engine
Late-war Allison V-1710 series
Structural Enhancements
Lengthened rear fuselage to counter torque from the more powerful engine.
Cut-down rear deck behind the cockpit provided improved rearward visibility.
Substantial efforts made to reduce airframe weight in early production blocks to enhance climb rate.
Armament Variations
Early P-40N blocks reduced wing armament to four .50 in (12.7 mm) machine guns.
Later blocks reinstated six-gun configurations following field complaints regarding firepower.
Operational Highlights
Supplied to the Commonwealth air forces as the Kittyhawk Mk IV.
Widely employed in a variety of roles including air combat, ground attack, and training.
Royal Australian Air Force (RAAF) received 553 P-40Ns, making it the most widely used variant by Australia.
Subvariant Diversity
Ranged from lightweight, high-speed “hot rod” interceptors capable of up to 380 mph to heavily equipped fighter-bombers.
Notable Aircraft
The 15,000th P-40 produced was a P-40N painted with the insignia of 28 nations that had flown Curtiss-Wright aircraft—though not all had operated the P-40 series specifically.
Field Nicknames & Legacy
In European operations by 1944, the P-40N was largely relegated to ground attack missions, earning the informal nickname “B-40”.
Post-war survivors redesignated ZF-40N as of June 1948.
P-40P
Cancelled Subvariant
Planned Configuration
Intended to be powered by the V-1650-1 Merlin engine, consistent with P-40F/L lineage.
Order Quantity
1,500 aircraft authorised.
Production Outcome
Ultimately constructed as P-40Ns, utilising the Allison V-1710-81 engines instead.
Curtiss XP-40Q, P-40R, RP-40, TP-40 & “Twin P-40”
XP-40Q
Final Prototype Development
Prototype Count
Three modified P-40N airframes
Key Modifications
Four-bladed propeller
Cut-down rear fuselage paired with a bubble canopy for improved visibility
Squared-off wingtips and tail surfaces
Four wing-mounted .50 in (12.7 mm) machine guns
Upgraded Allison engine featuring a two-speed supercharger
Performance
Achieved a top speed of 422 mph (679 km/h), making it the fastest P-40 variant ever produced.
Evaluation Outcome
Despite considerable aerodynamic and engine enhancements, the XP-40Q did not offer sufficient performance gains compared to late-war production aircraft like the P-47D Thunderbolt and P-51D Mustang.
Consequently, the model was not approved for mass production.
Note
No P-40 variant equipped with a single-speed supercharger could exceed 400 mph (640 km/h), highlighting the XP-40Q’s advanced high-altitude capability.
P-40R
Field Retrofit Designation
Definition
Applied to P-40F and P-40L aircraft retrofitted with Allison engines in the field.
Purpose
Standardised engine types across squadrons to simplify logistics and maintenance.
RP-40 Reconnaissance Conversion
Usage
Selected U.S. Army Air Forces P-40s modified for reconnaissance roles.
Changes
Typically involved camera installations and removal of armament to reduce weight and improve range.
TP-40 Trainer Variant
Configuration
Conversion of standard P-40s into two-seat training aircraft.
Role
Used for advanced instruction and transition training for combat pilots.
Twin P-40
Experimental Mock-up
Concept
A unique visual mock-up featuring two Merlin engines mounted atop each wing, situated above the main landing gear.
Status
Only one photograph of this configuration is known to exist.
Purpose
Likely an experimental or promotional display, with no known operational use or flight trials.
