Draft:Curtis H81 Hawk

References

Curtiss H-81 Hawk

The Curtiss H-81 Hawk was the export designation for early variants of the Curtiss P-40 Warhawk fighter aircraft produced by the Curtiss-Wright Corporation in the United States. Known in British Commonwealth service as the Tomahawk, the H-81 became one of the first American-built fighters to see extensive combat during the Second World War and is particularly associated with the American Volunteer Group (AVG), the "Flying Tigers," in China.

Development

In 1938, Curtiss began developing a fighter based on the P-36 Hawk airframe but powered by the liquid-cooled Allison V-1710 engine. The resulting aircraft, designated P-40 by the U.S. Army Air Corps, attracted significant foreign interest before the United States entered the war.

Export aircraft were assigned the manufacturer designation Model 81, and military export contracts used the designation H-81. Britain became the principal early customer, ordering hundreds of aircraft in 1940 as losses mounted during the Battle of Britain. Although the H-81 arrived too late to participate significantly in that battle, it entered service with the Royal Air Force as the Tomahawk Mk I and Mk II. National Museum of the U.S. Air Force: P-40 Warhawk Imperial War Museums: Tomahawk / P-40 collections

Design

The H-81 was a single-seat, all-metal monoplane fighter with a retractable landing gear and an Allison V-1710 V-12 engine. Early export variants carried two synchronized .50 in (12.7 mm) machine guns in the nose and additional wing-mounted guns.

Pilots generally considered the aircraft:

Rugged and capable of absorbing battle damage

Fast at low and medium altitudes

Less effective at high altitude than contemporary European fighters such as the Supermarine Spitfire and Messerschmitt Bf 109F

The aircraft's relatively heavy structure and good diving characteristics made it effective in boom-and-zoom tactics. Smithsonian National Air and Space Museum: P-40 Warhawk

Operational history Royal Air Force

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The RAF received its first Tomahawks in 1940. Because the type lacked a suitable high-altitude supercharger, RAF commanders initially used it for tactical reconnaissance, army cooperation, and low-altitude interception. In the North African Campaign, Tomahawk squadrons operated against Italian and German forces and gained a reputation for durability in harsh desert conditions. RAF Museum: Curtiss Tomahawk

Flying Tigers

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The most famous H-81 operators were the American Volunteer Group, commanded by Claire Lee Chennault. Beginning combat operations in December 1941, AVG pilots flew H-81A-2 aircraft supplied originally under British contracts.

Using Chennault's tactics of diving attacks, mutual support, and avoiding turning combat with Japanese fighters, the AVG achieved a notable combat record during the defense of China and the Burma Road. The distinctive shark-mouth nose art applied to AVG H-81s became one of the most recognizable aircraft markings of the war. The National WWII Museum: Flying Tigers HistoryNet: Flying Tigers overview

Soviet service

A smaller number of early P-40/H-81 aircraft reached the Soviet Union through Lend-Lease. Soviet pilots valued the aircraft's strong construction and radio equipment, though performance at high altitude remained a limitation on the Eastern Front.

Variants

Variant

Description

H-81A-1

Early export version comparable to the P-40B.

H-81A-2

Export fighter delivered to the AVG and RAF; equivalent to the P-40C/Tomahawk IIB.

Tomahawk Mk I

RAF designation for the initial British batch.

Tomahawk Mk IIA/IIB

Improved RAF variants with additional armament and equipment.

Specifications (H-81A-2 / Tomahawk IIB)

Crew

1

Length

9.66 m (31 ft 8 in)

Wingspan

11.38 m (37 ft 4 in)

Height

3.76 m (12 ft 4 in)

Powerplant

1 × Allison V-1710-33 V-12

Maximum speed

≈ 352 mph (567 km/h)

Range

≈ 730 mi (1,175 km)

Service ceiling

≈ 29,000 ft (8,800 m)

Armament

2 × .50 in nose MGs, 4 × .30 in wing MGs, bombs up to 500 lb

Legacy

Although later P-40 variants such as the Kittyhawk received more powerful engines and heavier armament, the H-81/Tomahawk occupies a unique place in aviation history. It represented:

One of the earliest large-scale exports of a modern American fighter.

The principal aircraft of the Flying Tigers during their most famous operations.

A key Allied fighter in the opening months of the Pacific and China-Burma-India campaigns.

Surviving H-81 aircraft are preserved in museums in the United States, United Kingdom, and other countries, and several airworthy restorations continue to appear at major airshows.

See also

Curtiss P-40 Warhawk

Flying Tigers

Claire Lee Chennault

North African campaign

References

National Museum of the U.S. Air Force — Curtiss P-40 Warhawk. museum fact sheet

Smithsonian National Air and Space Museum — Curtiss P-40E Warhawk. collection entry

RAF Museum — Curtiss Tomahawk. RAF collections and research

The National WWII Museum — The Flying Tigers.