The Hawker Horsley was a British single-engined

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 ...

bomber A bomber is a military combat aircraft designed to attack ground and naval targets by dropping air-to-ground weaponry (such as bombs), launching aerial torpedo, torpedoes, or deploying air-launched cruise missiles. The first use of bombs dropped ...

of the 1920s. It was the last all-wooden aircraft built 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 ...

, and served as a medium day bomber and

torpedo bomber A torpedo bomber is a military aircraft designed primarily to attack ships with aerial torpedoes. Torpedo bombers came into existence just before the First World War almost as soon as aircraft were built that were capable of carrying the weight ...

with Britain's

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) and ...

between 1926 and 1935, as well as the navies of Greece and Denmark.

Design and development

The Horsley (named after Sir

Thomas Sopwith Sir Thomas Octave Murdoch Sopwith, CBE, Hon FRAeS (18 January 1888 – 27 January 1989) was an English aviation pioneer, businessman and yachtsman. Early life Sopwith was born in Kensington, London, on 18 January 1888. He was the eig ...

's home of

Horsley Towers Horsley Towers, East Horsley, Surrey, England is a country house dating from the 19th century. The house was designed by Charles Barry for the banker William Currie. The East Horsley estate was later sold to William King-Noel, 1st Earl of Lovelac ...

) was originally designed to meet Air Ministry Specification 26/23 for a day bomber powered by a single

Rolls-Royce Condor The Rolls-Royce Condor aircraft piston engine was a larger version of the Rolls-Royce Eagle developing up to 675 horsepower (500 kW). The engine first ran in 1918 and a total of 327 engines were recorded as being built. Variants ''Note:'' ...

engine.. While the specification called for any production aircraft to be of metal construction, Hawker proposed to build the prototype of wooden construction, gradually switching to a metal structure during production. This was acceptable to 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 State ...

, and an order for a single prototype was placed. The first prototype was flown in March 1925, powered by a engine, and was 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 ...

Martlesham Heath Martlesham Heath village is situated 6 miles (10 km) east of Ipswich, in Suffolk, England. This was an ancient area of heathland and latterly the site of Martlesham Heath Airfield. A "new village" was established there in the mid-1970s and th ...

on 4 May 1925. Meanwhile, the Air Ministry revised its requirements, producing Specification 23/25 which increased the required payload from one to two bombs. At the same time, it also issued Specification 24/25 for a torpedo bomber, required to carry a

torpedo A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, su ...

.. The Horsley's ability to cope with the increased loads required to meet these new specifications led to the design being favoured by the RAF, with an initial order of forty aircraft, consisting of ten wooden Mk Is and 30 Mk IIs of mixed metal and wood construction, being placed..

Description

The Horsley was a large single-engined two-bay

. It had a crew of two, comprising a pilot and a gunner/bomb-aimer/radio operator, who had a .303 in (7.7 mm) Lewis gun mounted in a

Scarff ring The Scarff ring was a type of machine gun mounting developed during the First World War by Warrant Officer (Gunner) F. W. Scarff of the Admiralty Air Department for use on two-seater aircraft. The mount incorporated bungee cord suspension in eleva ...

in the rear cockpit and a prone position for bomb aiming. The rear cockpit was also fitted with dual controls. The payload included two bombs, one bomb or a torpedo weighing . The structure was originally all wood, but before production was complete an all-metal structure was introduced, made in what became the famous Hawker system of metal construction. The three methods of construction were designated: Horsley Mk I for the all-wooden aircraft, Horsley Mk II for the mixed material, and (unofficially) Horsley III for the all-metal aircraft. Some aircraft were fitted with floats. Two aircraft, known as the Hawker Dantorp and powered by Leopard II engines were sold to the Danish Government. They had a slightly different fuselage, accommodating a third crew member. The Danes also purchased a licence to build a further ten aircraft at the Danish Naval Workshops (Orlogsvaerftet), but these were not built owing to a shortage of funds. Production aircraft were powered by the Condor IIIA, but the Horsley was also much used as a flying testbed for other engines, including the

Napier Lion The Napier Lion is a 12-cylinder, petrol-fueled 'broad arrow' W12 configuration aircraft engine built by D. Napier & Son from 1917 until the 1930s. A number of advanced features made it the most powerful engine of its day and kept it in produ ...

Rolls-Royce Buzzard The Rolls-Royce Buzzard was a British piston aero engine of capacity that produced about . Designed and built by Rolls-Royce Limited it is a V12 engine of Bore and Stroke. Only 100 were made. A further development was the Rolls-Royce R e ...

Rolls-Royce Eagle The Rolls-Royce Eagle was the first aircraft engine to be developed by Rolls-Royce Limited. Introduced in 1915 to meet British military requirements during World War I, it was used to power the Handley Page Type O bombers and a number of oth ...

, the

Armstrong Siddeley Leopard The Armstrong Siddeley Leopard was a British 14-cylinder twin-row air-cooled radial aero engine developed in 1927 by Armstrong Siddeley. It was the most powerful radial engine in the world when introduced. Variants ;Leopard I :700 hp, medium ...

radial engine, the

Junkers Jumo Junkers Flugzeug- und Motorenwerke AG (JFM, earlier JCO or JKO in World War I, English: Junkers Aircraft and Motor Works) more commonly Junkers , was a major German aircraft and aircraft engine manufacturer. It was founded there in Dessau, Ge ...

diesel engine The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-call ...

and early versions of the

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 later ...

Operational history

The first aircraft were delivered to No 100 (Bomber) Squadron of the

in September 1927, with two more squadrons, No. 15 and No. 11 Squadrons receiving Horsleys by the end of the year, replacing the

Fairey Fawn The Fairey Fawn was a British single-engine light bomber of the 1920s. It was designed as a replacement for the Airco DH.9A and served with the Royal Air Force between 1924 and 1929. Development The Fairey Fawn was designed by F Duncanson ...

. The Horsleys proved greatly superior to the Fawn, carrying up to three times the bomb load over greater ranges and at higher speeds, while also being agile for their size, and were popular with their pilots. In October 1928, No. 36 Squadron formed at

Donibristle Donibristle ( sco, also Dunibirsle) was a house and estate in Fife, Scotland, on the coast of the Firth of Forth. Only the wings of the house remain, within the modern settlement of Dalgety Bay. They are now protected as a category A listed buil ...

Fife Fife (, ; gd, Fìobha, ; sco, Fife) is a council area, historic county, registration county and lieutenancy area of Scotland. It is situated between the Firth of Tay and the Firth of Forth, with inland boundaries with Perth and Kinross (i ...

, Scotland as a torpedo-bomber squadron. It was transferred to

Singapore Singapore (), officially the Republic of Singapore, is a sovereign island country and city-state in maritime Southeast Asia. It lies about one degree of latitude () north of the equator, off the southern tip of the Malay Peninsula, borde ...

in 1930, helping to suppress a rebellion in

Burma Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John Wells explai ...

as well as maintaining its torpedo bombing skills. 100 Squadron converted to the torpedo bombing role in 1930 to fill the gap in home-based defences. The Horsley was chosen to attempt a non-stop flight to India, with a specially modified aircraft, carrying much more fuel and taking off at a weight of over 14,000 lb (6,350 kg) took off from

RAF Cranwell Royal Air Force Cranwell or more simply RAF Cranwell is a Royal Air Force station in Lincolnshire, England, close to the village of Cranwell, near Sleaford. Among other functions, it is home to the Royal Air Force College (RAFC), which trai ...

on 20 May 1927, flown by

Flight Lieutenant Flight lieutenant is a junior commissioned rank in air forces that use the Royal Air Force (RAF) system of ranks, especially in Commonwealth countries. It has a NATO rank code of OF-2. Flight lieutenant is abbreviated as Flt Lt in the India ...

Roderick Carr Air Marshal Sir Charles Roderick Carr, (31 August 1891 – 15 December 1971) was a senior Royal Air Force commander from New Zealand. He held high command in the Second World War and served as Chief of the Indian Air Force. Education and mi ...

and L.E.M Gillman. It ran out of fuel ''en route'', however, ditching in the

Persian Gulf The Persian Gulf ( fa, خلیج فارس, translit=xalij-e fârs, lit=Gulf of Persis, Fars, ), sometimes called the ( ar, اَلْخَلِيْجُ ٱلْعَرَبِيُّ, Al-Khalīj al-ˁArabī), is a Mediterranean sea (oceanography), me ...

near

Bandar Abbas Bandar Abbas or Bandar-e ‘Abbās ( fa, , , ), is a port city and capital of Hormozgān Province on the southern coast of Iran, on the Persian Gulf. The city occupies a strategic position on the narrow Strait of Hormuz (just across from Musan ...

Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...

. Despite this it had covered a distance of , which was sufficient to set a new world distance record, but was beaten in turn within a few hours by

Charles Lindbergh Charles Augustus Lindbergh (February 4, 1902 – August 26, 1974) was an American aviator, military officer, author, inventor, and activist. On May 20–21, 1927, Lindbergh made the first nonstop flight from New York City to Paris, a distance o ...

, whose solo Atlantic flight between New York and Paris in the ''

Spirit of St. Louis The ''Spirit of St. Louis'' (formally the Ryan NYP, registration: N-X-211) is the custom-built, single-engine, single-seat, high-wing monoplane that was flown by Charles Lindbergh on May 20–21, 1927, on the first solo nonstop transatlant ...

'' covered ). The Horsleys remained in service in the day-bombing role until 1934, with 504 Squadron's Horsleys being replaced by

Westland Wallace The Westland Wallace was a British two-seat, general-purpose biplane of the Royal Air Force, developed by Westland as a follow-on to their successful Wapiti. As the last of the interwar general purpose biplanes, it was used by a number of frontl ...

s in March 1934. No 36 Squadron at Singapore retained the Horsely in the Torpedo bomber role until July 1935. The last Horsley, a Merlin-powered testbed flew its final flight at

RAE Farnborough The Royal Aircraft Establishment (RAE) was a British research establishment, known by several different names during its history, that eventually came under the aegis of the UK Ministry of Defence (MoD), before finally losing its identity in mer ...

on 7 March 1938. A total of 124 Horsleys were built, including six aircraft for the Hellenic Naval Air Service and the two related Dantorps built for Denmark.

Operators

; * Marinens Flyvevæsen ; *

Hellenic Air Force , colours = , colours_label = , march = , mascot = , anniversaries = 8 November , equipment = , equipment_label ...

Hellenic Naval Air Service The Naval Air Service ( el, Ναυτική Αεροπορική Υπηρεσία, ΝΑΥ) was the air arm of the Hellenic Navy from 1915 to 1930. The first aviation units in the Greek Armed Forces were formed in June 1912. In the subsequent Bal ...

; *

** No. 11 Squadron RAF **

No. 15 Squadron RAF Number 15 Squadron, sometimes written as No. XV Squadron, was a squadron of the Royal Air Force. It most recently operated the Panavia Tornado, Panavia Tornado GR4 from RAF Lossiemouth as No. XV (Reserve) Squadron. It was the RAF's Operational ...

** No. 25 Squadron RAF **

No. 33 Squadron RAF Number 33 Squadron of the Royal Air Force operates the Westland Puma HC.2 from RAF Benson, Oxfordshire. History First World War No. 33 Squadron of the Royal Flying Corps was formed from part of No. 12 Squadron at Filton on 12 January 1916. ...

** No. 36 Squadron RAF **

No. 100 Squadron RAF Number 100 Squadron is a former Royal Air Force squadron. It last operated the British Aerospace Hawk T1, providing 'aggressor' aircraft for air combat training from RAF Leeming in North Yorkshire, UK. History First World War No. 100 was est ...

No. 504 Squadron RAF No. 504 (County of Nottingham) Squadron was one of the Special Reserve Squadrons of the Auxiliary Air Force, and today is a reserve force of the RAF Regiment. It was integrated into the AAF proper in 1936. Based at RAF Cottesmore, Rutland, 504 Sq ...

No. 1 Flying Training School RAF The No. 1 Flying Training School (1 FTS) is the oldest military pilot training school in the world, currently used to deliver rotary training to aircrew of the British armed forces. History First formation (1919 – 1928) On 23 December 1919 ...

Royal Air Force College Cranwell The Royal Air Force College (RAFC) is the Royal Air Force military academy which provides initial training to all RAF personnel who are preparing to become commissioned officers. The College also provides initial training to aircrew cadets and ...

** Anti-Aircraft Cooperation Flight

Specification (Horsley II day bomber)

References

Notes

Bibliography

* * * * * Thomas, Andrew. "In the Footsteps of Daedulus: Early Greek Naval Aviation". ''Air Enthusiast'', No. 94, July–August 2001, pp. 8–9.

External links

A history of Greek military equipment (1821-today): Hawker Horsley MkII

– British Aircraft of World War II {{Hawker Aircraft aircraft 1920s British bomber aircraft Horsley Single-engined tractor aircraft Aircraft first flown in 1925 Biplanes