The Hawker Hart is a British two-seater

biplane A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While a ...

light bomber aircraft that saw service with 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 ...

(RAF). It was designed during the 1920s by Sydney Camm and manufactured by

Hawker Aircraft Hawker Aircraft Limited was a British aircraft manufacturer that was responsible for some of the most famous products in British aviation history. History Hawker had its roots in the aftermath of the First World War, which resulted in the bank ...

. The Hart was a prominent British aircraft in the inter-war period, but was obsolete and already side-lined for newer

monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing con ...

aircraft designs by the start of the Second World War, playing only minor roles in the conflict before being retired. Several major variants of the Hart were developed, including a navalised version for the

Royal Navy The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against Fr ...

aircraft carrier An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. Typically, it is the capital ship of a fleet, as it allows a ...

s. Beyond Britain, the Hart would be operated by a number of foreign nations, including Sweden,

Yugoslavia Yugoslavia (; sh-Latn-Cyrl, separator=" / ", Jugoslavija, Југославија ; sl, Jugoslavija ; mk, Југославија ;; rup, Iugoslavia; hu, Jugoszlávia; rue, label= Pannonian Rusyn, Югославия, translit=Juhoslavij ...

Estonia Estonia, formally the Republic of Estonia, is a country by the Baltic Sea in Northern Europe. It is bordered to the north by the Gulf of Finland across from Finland, to the west by the sea across from Sweden, to the south by Latvia, an ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...

, and Canada.

Design and development

In 1926, the

Air Ministry The Air Ministry was a department of the Government of the United Kingdom with the responsibility of managing the affairs of the Royal Air Force, that existed from 1918 to 1964. It was under the political authority of the Secretary of Stat ...

stated a

requirement In product development and process optimization, a requirement is a singular documented physical or functional need that a particular design, product or process aims to satisfy. It is commonly used in a formal sense in engineering design, includ ...

for a two-seat high-performance light day-bomber, to be of all-metal construction and with a maximum speed of 160 mph (258 km/h). Designs were tendered by Hawker,

Avro AVRO, short for Algemene Vereniging Radio Omroep ("General Association of Radio Broadcasting"), was a Dutch public broadcasting association operating within the framework of the Nederlandse Publieke Omroep system. It was the first public broa ...

and

de Havilland The de Havilland Aircraft Company Limited () was a British aviation manufacturer established in late 1920 by Geoffrey de Havilland at Stag Lane Aerodrome Edgware on the outskirts of north London. Operations were later moved to Hatfield in H ...

. Fairey, who had sold a squadron's worth of its wooden Fox bomber in 1925, was not at first invited to tender to the specification, and was sent a copy of the specification only after protesting to the Chief of the Air Staff,

Hugh Trenchard Marshal of the Royal Air Force Hugh Montague Trenchard, 1st Viscount Trenchard, (3 February 1873 – 10 February 1956) was a British officer who was instrumental in establishing the Royal Air Force. He has been described as the "Father of the ...

.Jarrett ''Aeroplane Monthly'' May 1995, p. 13.Taylor 1974, p. 196. Hawker's design was a

single-bay A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While a ...

V12 engine A V12 engine is a twelve-cylinder piston engine where two banks of six cylinders are arranged in a V configuration around a common crankshaft. V12 engines are more common than V10 engines. However, they are less common than V8 engines. The f ...

(the engine that later became known as the Rolls-Royce Kestrel). It had, as the specification required, a metal structure, with a fuselage structure of steel-tube covered by

aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It ha ...

panels and fabric, with the wings having steel

spars The United States Coast Guard (USCG) Women's Reserve, also known as the SPARS (SPARS was the acronym for "Semper Paratus—Always Ready"), was the women's branch of the United States Coast Guard Reserve. It was established by the United States ...

and

duralumin Duralumin (also called duraluminum, duraluminium, duralum, dural(l)ium, or dural) is a trade name for one of the earliest types of age hardening, age-hardenable aluminium alloys. The term is a combination of ''Dürener'' and ''aluminium''. Its ...

ribs The rib cage, as an enclosure that comprises the ribs, vertebral column and sternum in the thorax of most vertebrates, protects vital organs such as the heart, lungs and great vessels. The sternum, together known as the thoracic cage, is a semi- ...

, covered in fabric. The crew of two sat in individual tandem cockpits, with the pilot sitting under the wing trailing edge, and operating a single .303 in (7.7 mm)

Vickers machine gun The Vickers machine gun or Vickers gun is a water-cooled .303 British (7.7 mm) machine gun produced by Vickers Limited, originally for the British Army. The gun was operated by a three-man crew but typically required more men to move and o ...

mounted on the port side of the cockpit. The observer sat behind the pilot, and was armed with a single Lewis gun on a ring mount, while for bomb-aiming, he lay prone under the pilot's seat.Jarrett ''Aeroplane Monthly'' June 1995, pp. 30–32. Up to 520 pounds (240 kg) of bombs could be carried under the aircraft's wings.Mason 1991, p. 170. '' J9052'', the prototype Hart, first flew in June 1928, being delivered to the

Aeroplane and Armament Experimental Establishment The Aeroplane and Armament Experimental Establishment (A&AEE) was a research facility for British military aviation from 1918 to 1992. Established at Martlesham Heath, Suffolk, the unit moved in 1939 to Boscombe Down, Wiltshire, where its work ...

RAF Martlesham Heath Royal Air Force Martlesham Heath or more simply RAF Martlesham Heath is a former Royal Air Force station located southwest of Woodbridge, Suffolk, England. It was active between 1917 and 1963, and played an important role in the development o ...

on 8 September. It demonstrated good performance and handling, reaching 176 mph (283 km/h) in level flight and in a vertical dive.Jarrett ''Aeroplane Monthly'' May 1995, p. 14.Mason 1994, p. 205. The competition culminated in the choice of the Hawker Hart in April 1929. The

de Havilland Hound The de Havilland DH.65 Hound was a 1920s British two-seat day bomber built by de Havilland at Stag Lane Aerodrome. History The Hound was designed as a two-seat general purpose biplane, a private venture to meet Air Ministry Specification 12/ ...

was rejected due to handling problems during landing and because of its part-wooden primary structure. While the Avro Antelope demonstrated similar performance and good handling, the Hart was preferred as it was far cheaper to maintain, a vital aspect to a programme during defence budget constraints that the British armed forces faced during the 1920s. The Fairey Fox IIM (which despite the name was a new aircraft), delayed by Fairey's late start on the design compared to the other competitors, only flew for the first time on 25 October 1929, long after the Hart had been selected. A total of 992 aircraft were built as Harts. It became the most widely used light bomber of its time and the design would prove to be a successful one with a number of derivatives, including the Hawker Hind and

Hector In Greek mythology, Hector (; grc, Ἕκτωρ, Hektōr, label=none, ) is a character in Homer's Iliad. He was a Trojan prince and the greatest warrior for Troy during the Trojan War. Hector led the Trojans and their allies in the defense o ...

. There were a number of Hart variants, though only slight alterations were made to the design. The Hart India was a tropical version, the Hart Special was a tropical

Hawker Audax The Hawker Hart is a British two-seater biplane light bomber aircraft that saw service with the Royal Air Force (RAF). It was designed during the 1920s by Sydney Camm and manufactured by Hawker Aircraft. The Hart was a prominent British aircra ...

, a Hart variant with desert equipment; a specialised Hart Trainer was also built which dispensed with the gunner's ring. Vickers built 114 of the latter model at Weybridge between 1931 and June 1936. The production Hart day bomber had a 525 hp (390 kW)

Rolls-Royce Kestrel The Kestrel or type F is a 21 litre (1,300 in³) 700 horsepower (520 kW) class V-12 aircraft engine from Rolls-Royce, their first cast-block engine and the pattern for most of their future piston-engine designs. Used during the interwar ...

IB 12-cylinder V-type engine; a speed of 184 mph (296 km/h) and a range of 470 mi (757 km). It was faster than most contemporary fighters, an astonishing achievement considering it was a light bomber. It also enjoyed excellent manoeuvrability, making the Hart one of the most effective biplane bombers ever produced for the Royal Air Force. In particular, it was faster than the

Bristol Bulldog The Bristol Bulldog is a British Royal Air Force single-seat biplane fighter designed during the 1920s by the Bristol Aeroplane Company. More than 400 Bulldogs were produced for the RAF and overseas customers, and it was one of the most fam ...

, which had recently entered service as the RAF's front line fighter. This disparity in performance led the RAF to gradually replace the Bulldog with the

Hawker Fury The Hawker Fury is a British biplane fighter aircraft used by the Royal Air Force in the 1930s. It was a fast, agile aircraft, and the first interceptor in RAF service capable of speed higher than 200 mph (321 kmh). It was the fighter co ...

. Demand was such that production was spread out among a wide selection of aircraft companies. Of the 962 built in the United Kingdom, Hawker produced 234,

Armstrong Whitworth Sir W G Armstrong Whitworth & Co Ltd was a major British manufacturing company of the early years of the 20th century. With headquarters in Elswick, Newcastle upon Tyne, Armstrong Whitworth built armaments, ships, locomotives, automobiles and ...

456, Gloster 46,

Vickers Vickers was a British engineering company that existed from 1828 until 1999. It was formed in Sheffield as a steel foundry by Edward Vickers and his father-in-law, and soon became famous for casting church bells. The company went public i ...

226 and 42 were produced in Sweden under licence by ASJA who built 18,

Götaverken Götaverken was a shipbuilding company that was located on Hisingen, Gothenburg. During the 1930s it was the world's biggest shipyard by launched gross registered tonnage. It was founded in 1841, and went bankrupt in 1989. History The company wa ...

who built three and the Central Workshops of the Air Force (CVM) who built 21."Hawker Hart."
''aeroflight.co.'' Retrieved: 4 December 2012. 1004 Harts were produced.

Operational history

The Hart entered service with No. 33 Squadron RAF in February 1930, replacing the larger and slower

Hawker Horsley The Hawker Horsley was a British single-engined biplane bomber of the 1920s. It was the last all-wooden aircraft built by Hawker Aircraft, and served as a medium day bomber and torpedo bomber with Britain's Royal Air Force between 1926 and 1935 ...

. No. 12 Squadron replaced its Foxes with Harts in January 1931, with a further two British-based Hart light bomber squadrons forming during 1931.Thetford ''Aeroplane Monthly'' July 1995, p. 51. Harts were deployed to the Middle East during the

Abyssinia Crisis The Abyssinia Crisis (; ) was an international crisis in 1935 that originated in what was called the Walwal incident during the ongoing conflict between the Kingdom of Italy and the Empire of Ethiopia (then commonly known as "Abyssinia"). The Le ...

of 1935–1936. The Hart saw extensive and successful service on the North-West Frontier,

British India The provinces of India, earlier presidencies of British India and still earlier, presidency towns, were the administrative divisions of British governance on the Indian subcontinent. Collectively, they have been called British India. In one ...

during the inter-war period. Four Hawker Harts from the

Swedish Air Force The Swedish Air Force ( sv, Svenska flygvapnet or just ) is the air force branch of the Swedish Armed Forces. History The Swedish Air Force was created on 1 July, 1926 when the aircraft units of the Army and Navy were merged. Because of the e ...

saw action as dive bombers during the 1939–1940

Winter War The Winter War,, sv, Vinterkriget, rus, Зи́мняя война́, r=Zimnyaya voyna. The names Soviet–Finnish War 1939–1940 (russian: link=no, Сове́тско-финская война́ 1939–1940) and Soviet–Finland War 1 ...

as part of a Swedish volunteer squadron, designated F19, fighting on the Finnish side. Though obsolete compared to the United Kingdom's opposition at the start of the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ...

, the Hart continued in service, mainly performing in the communications and training roles until being declared obsolete in 1943. The Hart proved to be a successful export, seeing service with the Royal

Egyptian Air Force The Egyptian Air Force (EAF) ( ar, القوات الجوية المصرية, El Qūwāt El Gawīyä El Maṣrīya), is the aviation branch of the Egyptian Armed Forces that is responsible for all airborne defence missions and operates all mili ...

, Royal

Indian Air Force The Indian Air Force (IAF) is the air force, air arm of the Indian Armed Forces. Its complement of personnel and aircraft assets ranks third amongst the air forces of the world. Its primary mission is to secure Indian airspace and to conduct ...

South African Air Force "Through hardships to the stars" , colours = , colours_label = , march = , mascot = , anniversaries = , equipment ...

Estonian Air Force The Estonian Air Force ( et, Õhuvägi, ) is the aviation branch of the Estonian Defence Forces. The air force traces its history to 1918, and was re-established in its current form in 1991. As of 2016, the Estonian Air Force has a strength of ...

Southern Rhodesia Southern Rhodesia was a landlocked self-governing colony, self-governing British Crown colony in southern Africa, established in 1923 and consisting of British South Africa Company (BSAC) territories lying south of the Zambezi River. The reg ...

, Sweden (where it was designated B4) and the

Kingdom of Yugoslavia The Kingdom of Yugoslavia ( sh-Latn-Cyrl, separator=" / ", Kraljevina Jugoslavija, Краљевина Југославија; sl, Kraljevina Jugoslavija) was a state in Southeast and Central Europe that existed from 1918 until 1941. From 191 ...

. The Rhodesian Hardys saw service on the Allied side during the opening moves of the East African theatre of World War II. Swedish Air Force General Björn Bjuggren wrote in his memoirs how his squadron developed

dive-bombing A dive bomber is a bomber aircraft that dives directly at its targets in order to provide greater accuracy for the bomb it drops. Diving towards the target simplifies the bomb's trajectory and allows the pilot to keep visual contact througho ...

techniques in the mid-1930s for their B4s. When the Hawker engineers found out, they issued a formal objection, saying that the aircraft had not been designed for that purpose. However, the Swedish pilots proved that the aircraft was up to the task and dispelled their concerns.

Variants

Hart

;Hart I :Two-seat light bomber aircraft for the RAF. 525 hp Kestrel IB engine.Mason 1991, p. 488. ;Hart SEDB :Two-seat single-engined light bomber aircraft for the RAF, powered by a 525 hp Rolls-Royce Kestrel IB, or a 510 hp Kestrel X (DR) piston engine.Mason 1991, p. 492. ;Hart (India) :Tropicalised version for the RAF, used by RAF in the North West Frontier of India, with larger radiator and extra equipment.Jarrett ''Aeroplane Monthly'' May 1995, p. 15. ;Hart (C) :Two-seat unarmed communications aircraft for the RAF, a small number were used by No. 24 Squadron RAF; eight built.Mason 1991, pp. 490, 494. ;Hart Trainer (Interim) :Hart light bombers converted into training aircraft. Two built.Mason 1991, p. 160. ;Hart Trainer :Two-seat dual-control trainer aircraft, with reduced sweepback on top wings to compensate for movement in center of gravity caused by removal of military equipment.Mason 1991, p. 161. ;Hart Fighter :Two-seat fighter version for the RAF used by No. 23 Squadron RAF, with Kestrel IIS. Later redesignated as the Demon; six built.Mason 1991, p. 489. ;Hart (Special) :Tropicalised version for the RAF, used by the RAF in the Middle East. Based on Audax airframe with desert equipment, and de-rated Kestrel X engine.Wixey ''Air Enthusiast'' January/February 2002, pp. 57–58.Mason 1991, p. 159. ;Hart (Testbeds) :Several Harts were used as engine testbeds, including ''G-ABMR'' and ''G-ABTN'' which were used to test several variants of Kestrel engines. ''K2434'' was used by Napier to test the Napier Dagger I, II and III. ''K3036'' was used by Rolls-Royce to test the Merlin C and E, complete with a ventral radiator. ;Estonian Hart :Export version for Estonia, equipped with an interchangeable wheel or float undercarriage; eight built.Mason 1991, p. 165.Wixey ''Air Enthusiast'' November/December 2001, pp. 28–29. Hawker Hart, B 4

;Swedish Hart :Light bomber for Swedish Air Force. Four Hawker-built pattern aircraft, powered by a Bristol Pegasus IM2 radial piston engine were delivered in 1934. Following successful evaluation, 42 were built under licence in Sweden by AB Götaverken of Göteborg, powered by a Swedish-built

NOHAB NOHAB (Nydqvist & Holm AB) was a manufacturing company based in the city of Trollhättan, Sweden. History The company was founded by Antenor Nydqvist, Johan Magnus Lidström and Carl Olof Holm in 1847 as ''Trollhättans Mekaniska Verkstad'' as ...

Pegasus IU2.

Audax

The Hawker Audax was a Hart variant, designed for army cooperation, seeing much service in the

British Empire The British Empire was composed of the dominions, colonies, protectorates, mandates, and other territories ruled or administered by the United Kingdom and its predecessor states. It began with the overseas possessions and trading posts e ...

. The first Audax flew in late 1931 and over 700 Audaxes were produced (including export). The Audax was similar to the Hart, though had some modifications, including a hook to pick up messages. It was armed with a single .303 in (7.7 mm) Lewis light machine gun and a .303 in (7.7 mm) Vickers machine gun and was powered by a version of the Kestrel engine and had a maximum speed of . A number of variants of the Audax were produced, including the Audax India, a tropicalised version of the Audax for service in India and the Audax Singapore for service there. HAudax

Other air forces which also used the Audax included the

Royal Canadian Air Force The Royal Canadian Air Force (RCAF; french: Aviation royale canadienne, ARC) is the air and space force of Canada. Its role is to "provide the Canadian Forces with relevant, responsive and effective airpower". The RCAF is one of three environm ...

, the

Royal Indian Air Force The Royal Indian Air Force (RIAF) was the aerial force of British India and later the Dominion of India. Along with the Indian Army, and Royal Indian Navy, it was one of the Armed Forces of British Indian Empire. The Indian Air Force was offi ...

, the

South African Air Force "Through hardships to the stars" , colours = , colours_label = , march = , mascot = , anniversaries = , equipment ...

, the

Royal Egyptian Air Force The Egyptian Air Force (EAF) ( ar, القوات الجوية المصرية, El Qūwāt El Gawīyä El Maṣrīya), is the aviation branch of the Egyptian Armed Forces that is responsible for all airborne defence missions and operates all milit ...

, the

Royal Iraqi Air Force The Iraqi Air Force (IQAF or IrAF) ( ar, القوات الجوية العراقية, Al Quwwat al Jawwiyah al Iraqiyyah}) is the aerial warfare service branch of the Iraqi Armed Forces. It is responsible for the defense of Iraqi airspace as well ...

, the

Imperial Iranian Air Force The history of the Iranian Air Force, currently known as the Islamic Republic of Iran Air Force, can be divided into two phases—before the Islamic Revolution, and after it. Imperial era The Imperial Iranian Air Force (IIAF) was a branch ...

, the

Straits Settlements The Straits Settlements were a group of British territories located in Southeast Asia. Headquartered in Singapore for more than a century, it was originally established in 1826 as part of the territories controlled by the British East India Com ...

and the

Southern Rhodesian Air Force The Rhodesian Air Force (RhAF) was an air force based in Salisbury (now Harare) which represented several entities under various names between 1935 and 1980: originally serving the British self-governing colony of Southern Rhodesia, it was the ...

. During the Second World War the Audax saw limited service in Africa on the

Kenya ) , national_anthem = " Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...

–

Abyssinia The Ethiopian Empire (), also formerly known by the exonym Abyssinia, or just simply known as Ethiopia (; Amharic and Tigrinya: ኢትዮጵያ , , Oromo: Itoophiyaa, Somali: Itoobiya, Afar: ''Itiyoophiyaa''), was an empire that historica ...

border during the

Second Italo-Ethiopian War The Second Italo-Ethiopian War, also referred to as the Second Italo-Abyssinian War, was a war of aggression which was fought between Fascist Italy (1922–1943), Italy and Ethiopian Empire, Ethiopia from October 1935 to February 1937. In Ethio ...

. The Audax also saw service in Iraq, at RAF Habbaniya, west of

Baghdad Baghdad (; ar, بَغْدَاد , ) is the capital of Iraq and the second-largest city in the Arab world after Cairo. It is located on the Tigris near the ruins of the ancient city of Babylon and the Sassanid Persian capital of Ctesiphon ...

, after the uprising there, during the

Anglo-Iraqi War The Anglo-Iraqi War was a British-led Allied military campaign during the Second World War against the Kingdom of Iraq under Rashid Gaylani, who had seized power in the 1941 Iraqi coup d'état, with assistance from Germany and Italy. The ca ...

. In the days leading up to that battle crews began to upgrade the Audaxes stationed there, despite having received orders forbidding such actions. They fitted some to carry bombs instead of bombs. The Audax ended its service by 1945. A derivative of the Audax, the Hawker Hartebeest, a light bomber, was built for the South African Air Force with modifications made from the Audax. Sixty-five of these aircraft were built, the majority in South Africa. The aircraft saw action in East Africa during clashes against Italy who occupied Abyssinia. Hawker Audax K3077 26 Sq BTN 08

A.V. Roe built 287 Audaxes as part of the RAF expansion scheme during 1935–1937. These did not warrant an Avro type number but between 1937 and 1938, Avro built 24 modernised Audaxes for the Egyptian government, powered by Armstrong Siddeley Panther VIA radials. Acknowledging the amount of redesign work done, these were designated the Avro Type 674. Audax I :Two-seat army cooperation aircraft for the RAF, powered by a 530 hp (395 kW) Rolls-Royce Kestrel IB, or 580 hp Kestrel X piston engine. Audax (India) :Tropicalised version for the RAF, used by the RAF in India. Audax (Singapore) :Tropicalised version for the RAF, powered by a Rolls-Royce Kestrel V piston engine, used by the RAF in Singapore and

British Malaya The term "British Malaya" (; ms, Tanah Melayu British) loosely describes a set of states on the Malay Peninsula and the island of Singapore that were brought under British hegemony or control between the late 18th and the mid-20th century. ...

. Canadian Audax :Modified version of the Audax I for the

RCAF The Royal Canadian Air Force (RCAF; french: Aviation royale canadienne, ARC) is the air and space force of Canada. Its role is to "provide the Canadian Forces with relevant, responsive and effective airpower". The RCAF is one of three environm ...

; one built for Canada. Egyptian Audax :Six aircraft fitted with the 750 hp

Armstrong Siddeley Panther The Armstrong Siddeley Panther was a 27-litre 14-cylinder twin-row air-cooled Radial engine, radial aero engine developed by Armstrong Siddeley. It was originally named the Jaguar Major.Lumsden 2003, p.72. Applications * Armstrong Whitworth A ...

radial piston engine, plus 18 aircraft fitted with the Panther X radial piston engine; 34 built for Egypt. Iraqi Audax (Nisr) :24 aircraft fitted with the

Bristol Pegasus The Bristol Pegasus is a British nine-cylinder, single-row, air-cooled radial aero engine. Designed by Roy Fedden of the Bristol Aeroplane Company, it was used to power both civil and military aircraft of the 1930s and 1940s. Developed from t ...

IIM2 radial piston engine, plus ten aircraft fitted with the Pegasus VIP8 radial piston engine; 34 built for Iraq. Persian Audax :30 aircraft fitted with the

Pratt & Whitney Hornet The Pratt & Whitney R-1690 Hornet was a widely used American aircraft engine. Developed by Pratt & Whitney, 2,944 were produced from 1926 through 1942. It first flew in 1927. It was a single-row, 9-cylinder air-cooled radial design. Displacemen ...

S2B radial piston engine, plus 26 aircraft fitted with the Bristol Pegasus IIM or IIM2 radial piston engine; 56 built for Persia. Hartebeest :Hawker built pattern aircraft; four built and exported to South Africa. Hartebeest I :Two-seat general-purpose, ground support aircraft for the South African Air Force, powered by a 608 hp (453 kW) Rolls-Royce Kestrel VFP piston engine; 65 aircraft built under licence in South Africa.

Demon

The Hawker Demon was a fighter variant of the Hart light bomber. During air defence exercises the RAF's

Siskin The name siskin when referring to a bird is derived from an adaptation of the German dialect words ''sisschen'', ''zeischen'', which are diminutive forms of Middle High German (''zîsec'') and Middle Low German (''ziseke'', ''sisek'') words, which ...

s and

Bulldogs The Bulldog is a British breed of dog of mastiff type. It may also be known as the English Bulldog or British Bulldog. It is of medium size, a muscular, hefty dog with a wrinkled face and a distinctive pushed-in nose.Thetford ''Aeroplane Monthly'' July 1995, p. 56. While the

offered better performance, lower production volumes made it more expensive and therefore it remained available only in small numbers, so when a fighter version of the Hart was suggested, the Air Ministry selected the type as an interim fighter until higher-performance fighters could be bought in larger numbers.Mason 1992, p. 234. The new fighter variant added a second Vickers machine gun, while the coaming of the rear cockpit was angled to give a better field of fire, and a

supercharged In an internal combustion engine, a supercharger compresses the intake gas, forcing more air into the engine in order to produce more power for a given displacement. The current categorisation is that a supercharger is a form of forced indu ...

Kestrel IS engine was fitted. Evaluation of an initial batch of six aircraft, known as Hart Fighters by one flight of 23 Squadron during 1931 was successful, and larger orders followed for the fighter Hart, now known as the Hawker Demon.Mason 1991, p. 219. The Demon's first flight was on 10 February 1933. 305 Hawker Demons were built, including 232 for the RAF. The Demon was powered by versions of the Kestrel engine. It had an armament of a single rear .303 in (7.7 mm) Lewis Gun with two fixed .303 in (7.7 mm) Vickers machine guns in the nose. Many were fitted with a hydraulically-powered turret in the rear gunner's position, which had been tested on the Hawker Hart. Demons were also sold to the

Royal Australian Air Force "Through Adversity to the Stars" , colours = , colours_label = , march = , mascot = , anniversaries = RAAF Anniversary Commemoration ...

. It saw only second-line operations during the Second World War. Hawker Demon ExCC

Production of the Demon was undertaken by Hawker and by

Boulton Paul Aircraft Boulton Paul Aircraft Ltd was a British aircraft manufacturer that was incorporated in 1934, although its origins in aircraft manufacturing began earlier in 1914, and lasted until 1961. The company mainly built and modified aircraft under co ...

at their Wolverhampton factory, where their last example of 106 to be completed was delivered to the RAF in December 1937. ;Hart Two-Seat Fighter :Two-seat fighter version of the Hart for the RAF. Later redesignated as the Hart Fighter. ;Demon I :Two-seat fighter aircraft for the

RAF 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) and ...

. ;Australian Demon I :Two-seat fighter aircraft for the

RAAF "Through Adversity to the Stars" , colours = , colours_label = , march = , mascot = , anniversaries = RAAF Anniversary Commemoration ...

, similar to RAF version but fitted with a 600 hp (447 kW) Rolls-Royce Kestrel V engine; 54 built (the first 18 delivered as general-purpose fighters in 1935 and an additional 36 for army co-operation duties delivered in 1936). ;Australian Demon II :Two-seat training version for the RAAF, standard Demon fitted with dual controls and provision for target towing, 10 built ;Turret Demon :Two-seat fighter version, fitted with a

Frazer-Nash Frazer Nash was a brand of British sports car manufactured from 1922 first by Frazer Nash Limited founded by engineer Archibald Frazer-Nash. On its financial collapse in 1927 a new company, AFN Limited, was incorporated. Control of AFN passed ...

gun turret in the rear cockpit.

Hardy

The Hawker Hardy was a general-purpose variant of the ''Hawker Hart'' tropicalised to meet

Air Ministry Specification This is a partial list of the British Air Ministry (AM) specifications for aircraft. A specification stemmed from an Operational Requirement, abbreviated "OR", describing what the aircraft would be used for. This in turn led to the specification ...

G.23/33 as a Wapiti replacement in Iraq. The prototype was a production Hart which was modified with a modified radiator, a message pick-up hook, water containers and a desert survival kit. The prototype first flew on 7 September 1934, and the first production aircraft were delivered to 30 Squadron in January 1935. The ''Hardy'' saw some service during the Second World War, in Africa and the Middle East; the ''Hardys'' performing a number of operations against Italian-occupied Abyssinia as well as other areas of Africa. The ''Hardy'' also saw service with Southern Rhodesia. The last operational sortie by a Hardy was on 9 May 1941 and most of the survivors were scrapped, although some continued in service as communications aircraft. On 14 May 1941, the Belgian Colonial authorities obtained a Hawker Hardy from the South African Air Force. Painted in Belgian colours, the machine was used for observation missions, but unfortunately overturned while landing at Gambela airfield on 26 May 1941, effectively writing off the aircraft. ;Hardy I :Two-seat general-purpose aircraft for the RAF, 47 built excluding one prototype modified from a Hart.

Hind

The Hawker Hind was a derivative of the Hart and was intended to replace it. The

Hawker Hector The Hawker Hector was a British biplane army co-operation and liaison aircraft of the late 1930s; it served with the Royal Air Force and saw brief combat in the Battle of France in May 1940. Some Hectors were later sold to Ireland. It was name ...

was a variant of the Hind and was used in the army co-operation role. It saw only limited service during the Second World War with the Royal Air Force. Hectors were also sold to

Ireland Ireland ( ; ga, Éire ; Ulster-Scots: ) is an island in the North Atlantic Ocean, in north-western Europe. It is separated from Great Britain to its east by the North Channel, the Irish Sea, and St George's Channel. Ireland is the s ...

Osprey

The Hawker Osprey was the navalised carrier-borne version of the Hart, performing in the fighter and reconnaissance roles. The Osprey had a single Rolls-Royce Kestrel II engine, and had a max speed of 168 mph (270 km/h). Its armament consisted of a single forward .303 in (7.7 mm) Vickers machine gun and one .303 in (7.7 mm) Lewis gun. The Osprey joined the

Fleet Air Arm The Fleet Air Arm (FAA) is one of the five fighting arms of the Royal Navy and is responsible for the delivery of naval air power both from land and at sea. The Fleet Air Arm operates the F-35 Lightning II for maritime strike, the AW159 Wi ...

(FAA) in 1932, with 103 being built, and ended its career in 1944 after serving as a trainer for FAA pilots during the Second World War. By December 1936, Ospreys were being deployed by 701 Squadron based at

RAF Kalafrana RAF Kalafrana was a seaplane operations centre on the southernmost tip of Malta between 1917 and 1946 when it was transferred to the Royal Navy. It played an important role in both world wars, starting as a base for anti-submarine and anti-pirac ...

in the anti-submarine and anti-piracy role. The Osprey was also sold to the

being used on the

seaplane cruiser A cruiser is a type of warship. Modern cruisers are generally the largest ships in a fleet after aircraft carriers and amphibious assault ships, and can usually perform several roles. The term "cruiser", which has been in use for several hu ...

, which carried six Ospreys. Ospreys were also sold to the

Portuguese Naval Aviation The Portuguese Naval Aviation ( pt, Aviação Naval Portuguesa) constituted the air component of the Portuguese Navy, from 1917 to 1957. The Portuguese Air Force maritime patrol units and the Navy's Helicopter Squadron (EHM, ''Esquadrilha de Heli ...

and the

Spanish Republican Air Force The Spanish Republican Air Force was the air arm of the Armed Forces of the Second Spanish Republic, the legally established government of Spain between 1931 and 1939. Initially divided into two branches: Military Aeronautics ('' Aeronáutica ...

. ;Osprey I :Two-seat fleet spotter and reconnaissance aircraft, powered by a 630 hp (470 kW) Rolls-Royce Kestrel IIMS inline piston engine; 37 built. ;Osprey II :Two-seat fleet spotter and reconnaissance aircraft, powered by a 630 hp (470 kW) Rolls-Royce Kestrel IIMS piston engine, equipped with redesigned floats; 14 built. ;Osprey III :Two-seat fleet spotter and reconnaissance aircraft, powered by a 630 hp (470 kW) Rolls-Royce Kestrel IIMS piston engine, equipped with a dinghy stowed away in the starboard upper wing; 26 built. ;Osprey IV :Two-seat fleet spotter and reconnaissance aircraft, powered by a 640 hp Rolls-Royce Kestrel V. Twenty-six built in 1935.Mason 1991, p. 228. ;Portuguese Osprey :Two aircraft equivalent to Osprey III built for Portugal and powered by Kestrel IIMS piston engine. Delivered in 1935. Six aircraft more in 1939. ;Spanish Osprey :One aircraft fitted with a Hispano-Suiza 12Xbrs engine; one built for the

. ;Swedish Osprey :Version for Sweden fitted with a Swedish-built

Bristol Mercury radial piston engine and interchangeable wheel and float landing gear. Six built. Given the designation ''S 9'' by the

.Wixley ''Air Enthusiast'' January/February 2002, p. 63.Layman and McLaughlin 1991, pp. 41–42.

Operators

Hawker Hart

* * * * * * * * * * *

Hawker Audax

* * * * - No. 3 Squadron IqAFPesach Malovany, "Wars of Modern Babylon", University Press of Kentucky, June 2017, / , fn. 2, p.813. * * * *

Hawker Demon

* *

Hawker Hardy

* * * (one aircraft, ex-RAF K4316) *

Hawker Hartebeest

Hawker Osprey

* * * *

Surviving aircraft

Hawker Demon K8203 (Suttleworth uncovered)

;Australia * A1-8 – Demon I on static display at the

RAAF Museum RAAF Museum is the official museum of the Royal Australian Air Force, the second oldest air force in the world, located at RAAF Williams Point Cook, Victoria, Australia which is the oldest continuously operating Military Air Base in the world. T ...

Point Cook, Victoria Point Cook is a suburb in Melbourne, Victoria, Australia, south-west of Melbourne's Central Business District, located within the City of Wyndham local government area. Point Cook recorded a population of 66,781 at the 2021 census. Point ...

. Delivered 1935, served with No. 3 Squadron RAAF until 1937 when it was wrecked in

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

and reduced to components. Restored 1987 by 2AD in Richmond, New South Wales. ;Sweden * 714 – B 4 on static display at the Swedish Air Force Museum near Linköping, Östergötland. ;United Kingdom * G-ABMR – Hart II on static display at the

Royal Air Force Museum London The Royal Air Force Museum London (also commonly known as the RAF Museum) is located on the former Hendon Aerodrome. It includes five buildings and hangars showing the history of aviation and the Royal Air Force. It is part of the Royal Air Fo ...

London London is the capital and List of urban areas in the United Kingdom, largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary dow ...

. The 13th off the production line, it first flew in 1931 but never saw military use. Under the civilian registration ''G-ABMR'', it was used by Hawker in various roles, including testbed, demonstration aircraft and a camera aircraft. It flew throughout the Second World War and continued flying until 1971. Still airworthy, it was then transferred to the RAF Museum, on loan from

Hawker Siddeley Hawker Siddeley was a group of British manufacturing companies engaged in aircraft production. Hawker Siddeley combined the legacies of several British aircraft manufacturers, emerging through a series of mergers and acquisitions as one of onl ...

, Hawker Aircraft's successor company. It remains there, painted to represent RAF Hart serial number ''J9941''. * K4972 – Hart Trainer on static display at the

Royal Air Force Museum Cosford The Royal Air Force Museum Cosford, located in Cosford in Shropshire, is a free (currently, 2022) museum dedicated to the history of aviation and the Royal Air Force in particular. The museum is part of the Royal Air Force Museum, a non-departme ...

Cosford, Shropshire Cosford is a village in Shropshire, England. It is located on the A41 road, which is itself just south of junction 3 on the M54 motorway. The village is very small and is mostly made up of dwellings that house Royal Air Force personnel who work ...

. Built in 1935 by Armstrong Whitworth, it flew as a training aircraft before being used as an instructional airframe. In 1943, it passed on to the

Air Training Corps The Air Training Corps (ATC) is a British volunteer-military youth organisation. They are sponsored by the Ministry of Defence and the Royal Air Force. The majority of staff are volunteers, and some are paid for full-time work – including C ...

unit at Nelson Tomlinson School,

Wigton Wigton is a market town in the Allerdale borough of Cumbria, England. Historically in Cumberland, it lies just outside the Lake District in the borough of Allerdale. Wigton is at the centre of the Solway Plain, between the Caldbeck Fells an ...

, where it remained until recovered in 1962 by a group of aviation enthusiasts. They passed it on to the RAF Museum in 1962. * K8203 – Demon airworthy at the

Shuttleworth Collection The Shuttleworth Collection is a working aeronautical and automotive collection located at the Old Warden Aerodrome, Old Warden in Bedfordshire, England. It is the oldest in the world and one of the most prestigious, due to the variety of old ...

in Old Warden, Bedfordshire.

Specifications Hart (Kestrel IB powered day bomber)

References

Notes

Citations

Bibliography

* * * Crawford, Alex. ''Hawker Hart Family''. Redbourn, Hertfordshire, UK: Mushroom Model Publications Ltd., 2008. . * Gerdessen, Frederik. "Estonian Air Power 1918 – 1945". ''

Air Enthusiast ''Air Enthusiast'' was a British, bi-monthly, aviation magazine, published by the Key Publishing group. Initially begun in 1974 as ''Air Enthusiast Quarterly'', the magazine was conceived as a historical adjunct to ''Air International'' maga ...

'', No. 18, April – July 1982. pp. 61–76. . * Goulding, James and Robert Jones. ''Gladiator, Gauntlet, Fury, Demon'' (Camouflage & Markings 5: RAF Fighter Command Northern Europe, 1936 to 1945). London: Ducimus Books Ltd., 1971. OCLC 872045486 * Hannah, Donald. ''Hawker FlyPast Reference Library''. Stamford, Lincolnshire, UK: Key Publishing Ltd., 1982. . * James, Derek N. ''Hawker: An Aircraft Album No. 5''. New York: Arco Publishing Company, 1973. (first published in the UK by Ian Allan in 1972). * Jarrett, Philip. "By Day and by Night: Hawker Harts and Hinds: Part One". ''

Aeroplane Monthly ''Aeroplane'' (formerly ''Aeroplane Monthly'') is a British magazine devoted to aviation, with a focus on aviation history and preservation. __TOC__ ''The Aeroplane'' The weekly ''The Aeroplane'' launched in June 1911 under founding edito ...

'', May 1995, Vol. 23 No. 5, Issue No 265, pp. 12–18. London: IPC. ISSN 0143-7240. * Jarrett, Philip. "By Day and by Night: Hawker Harts and Hinds: Part Two". ''Aeroplane Monthly'', June 1995, Vol. 23 No. 6, Issue No 266, pp. 28–33. London: IPC. ISSN 0143-7240. * Layman, R. D. and Stephen McLaughlin. ''The Hybrid Warship: The Amalgamation of Big Guns and Aircraft''. London: Conway Maritime Press, 1991. . * Lewis, Peter. ''The British Bomber since 1914 Sixty Years of Design and Development.'' London: Putnam, 1974. . * * Mason, Francis K. ''The British Bomber Since 1914''. London: Putnam Aeronautical Books, 1994. . * Mason, Francis K. ''The British Fighter since 1912''. Annapolis, Maryland, USA:Naval Institute Press, 1992. . * Mason, Francis K. ''Hawker Aircraft since 1920.'' London: Putnam Aeronautical Books, 1991. . * Mason, Francis K. ''The Hawker Audax & Hardy'' (Aircraft in Profile 140). Leatherhead, Surrey, UK: Profile Publications, 1966. OCLC 45091982 * Rimell, Raymond Laurence. ''The Hart Family: Hawker Hart and Derivatives'' (Aeroguide Classics Number 5). Chipping Ongar, Essex, UK: Linewrights Ltd., 1989. . * Taylor, H. A. ''Fairey Aircraft since 1915''. London: Putnam, 1974. . * Thetford, Owen. "By Day and by Night: Hawker Hart and Hind": Operational History Part One. ''Aeroplane Monthly'', July 1995, Vol. 24 No. 1, Issue No 267, pp. 50–57. London: IPC. ISSN 0143-7240. * Wixey, Ken. "Hart of the Matter: Part One – Hawker's Hart 'Family': The Hart Bomber and the Army Co-Op Audax". ''

'', No 96, November/December 2001, pp. 24–33. Stamford UK:Key Publishing. ISSN 0143-5450 * Wixey, Ken. "Hart of the Matter: Part Two- Hawker's Hart 'Family': Demon, Hart Special, Trainer, Osprey, Hardy". ''Air Enthusiast'', No 97, January/February 2002, pp. 54–65. Stamford UK:Key Publishing. ISSN 0143-5450

External links

* {{Authority control Biplanes 1920s British bomber aircraft

Hart Hart often refers to: * Hart (deer) Hart may also refer to: Organizations * Hart Racing Engines, a former Formula One engine manufacturer * Hart Skis, US ski manufacturer * Hart Stores, a Canadian chain of department stores * Hart's Reptile Wo ...

Single-engined tractor aircraft Aircraft first flown in 1928

Design and development

Operational history

Variants

Hart

Audax

Demon

Hardy

Hind

Osprey

Operators

Hawker Hart

Hawker Audax

Hawker Demon

Hawker Hardy

Hawker Hartebeest

Hawker Osprey

Surviving aircraft

Specifications Hart (Kestrel IB powered day bomber)

See also

References

Notes

Citations

Bibliography

External links