Curtiss P-40 Warhawk

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.

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