The Cirrus and Hermes or Cirrus-Hermes are a series of British aero engines manufactured, under various changes of ownership, from the 1920s until the 1950s. The engines were all air-cooled, four-cylinder inline types, with earlier ones upright and later designs inverted.
26-527: General Aircraft Limited was a British aircraft manufacturer from its formation in 1931 to amalgamation with Blackburn Aircraft in 1949 to become Blackburn and General . Its main products were military gliders and light transport aircraft. On 27 February 1931, General Aircraft Limited (GAL) was formed to undertake production of aircraft using the 'monospar' wing designs of the Monospar Wing Company Ltd. Both firms were headed by Helmut J. Stieger,
52-451: A powerplant suited to a light two-seat sports biplane which would become the de Havilland Moth . No suitable engine, combining a suitable power output with light weight, low cost and high reliability existed at the time. The Aircraft Disposal Company (also known as Airdisco and ADC) were producing the low-cost Airdisco V8 which had been developed by Frank Halford from their large stocks of war surplus Renault V8 aero engines. The Renault
78-568: The Civilian Repair Organisation , to repair Supermarine Spitfires at Hanworth, and Beaufighters at Fairoaks. It also modified Hawker Hurricanes to enable catapult-launching from convoy escort ships. In 1943, Sikorsky helicopters were imported from the US for experimental work. Supplied in crates, they were assembled and flown at Hanworth Aerodrome – one squadron for the RAF, and two squadrons for
104-684: The Dumbarton ship building company, and Robert Blackburn resulted in the building of a new Blackburn factory at Barge Park, Dumbarton where production of the Blackburn Botha commenced in 1939. Blackburn amalgamated with General Aircraft Limited in 1949 as Blackburn and General Aircraft Limited, reverting to Blackburn Aircraft Limited by 1958. As part of the rationalisation of British aircraft manufacturers, its aircraft production and engine operations were absorbed into Hawker Siddeley and Bristol Siddeley respectively in 1960/1961. The Blackburn name
130-667: The Sopwith Cuckoo (1918) and the Fairey Swordfish (1942), both of which were built at Blackburn's Sherburn-in-Elmet factory. Related lists Blackburn Cirrus The first Cirrus design was created for the planned de Havilland Moth light aeroplane and, when it appeared in 1925, created the market for private flying. It and its successors were widely used for private and light aircraft from that moment on. The Cirrus engine originated in Geoffrey de Havilland 's 1924 quest for
156-618: The Cirrus III. Overall slightly shorter but with much the same overall weight, it delivered 105 horsepower (78 kW). American Cirrus Engines, Inc. was a subsidiary of Allied Motor Industries, Inc. set up at Belleville, N.J. in November 1928, initially to manufacture the Cirrus III under license. Having developed the American Cirrus III engine at New Jersey, the company moved to Marysville, Michigan, where it set up production. The engine
182-568: The Fleet Air Arm. Major overhauls were carried out at Hanworth on the helicopters, plus experimental work in Air Sea Rescue, limited by the weight-lifting capacity of the helicopters. After World War II, GAL diversified into the construction of pre-fabricated houses and car bodies. The company had designed and built a large transport aircraft, the GAL.60 Universal . However, GAL realised it did not have
208-517: The Hermes II B introduced a major change with the cylinders being inverted for the first time. The resulting high propeller line allowed the top of the engine to be lowered, which significantly improved the pilot's view in a single-engined type. All subsequent models would be inverted. By this time C. S. Napier, son of Montague Napier , had joined as technical director and engine designer. He began work on two new engines but before they could be finished
234-534: The Renault engines in 1928, Cirrus Aero Engines Limited was formed at Croydon to manufacture the Cirrus models from scratch. Although Halford was no longer associated with it (having gone off to develop the next-generation but otherwise similar de Havilland Gipsy series), the Cirrus company continued to develop new models, with the uprated Hermes appearing in 1929. It had been developed by ADC to provide more power than even
260-529: The Swiss inventor of the technique. GAL produced about 28 examples of the Monospar series of twin-engined light transport aircraft at Croydon Aerodrome between 1932 and 1934. In October 1934, both companies were re-capitalised by investment group British Pacific Trust, and were re-formed in a new company also named General Aircraft Limited. Also included in the new company were the assets of National Flying Services Ltd,
286-705: The UK company at cost. The company had factories at Olympia in Leeds, Sherburn-in-Elmet , Brough (East Yorkshire) and Dumbarton. In the early days, Blackburn himself flew aircraft on the beaches at Marske and Filey , with the company also using the former RAF Holme-on-Spalding Moor . Before production shifted to Sherburn-in-Elmet and Brough from the Leeds site, aircraft were flown in and out of Olympia works by an adjacent airstrip in Roundhay Park. The company also produced aircraft from other aircraft companies' specifications, such as
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#1733066171111312-626: The company came under new management. In 1934 the company was taken over by the Blackburn Aeroplane & Motor Company and moved to Brough in Yorkshire. Napier remained technical director and, while he completed the development and initial sales of the Cirrus Minor and Cirrus Major , Blackburn kept Cirrus Hermes as a separate company (though without the hyphen in its name). Although completely new designs, they were of broadly similar layout to
338-455: The conversion of 125 Hawker Hinds into trainers. In 1938, the company bought the design of the Cygnet light aircraft from the foundering C.W. Aircraft Ltd and it was further developed as the GAL.42 Cygnet II . GAL also operated an RAF elementary flying training school at Fairoaks Aerodrome , Surrey. During World War II, GAL became an important designer and manufacturer of gliders. It was part of
364-499: The factory at Hanworth was later closed. Blackburn Aircraft Blackburn Aircraft Limited was a British aircraft manufacturer from 1914 to 1963 that concentrated mainly on naval and maritime aircraft. Blackburn Aircraft was founded by Robert Blackburn and Jessy Blackburn , who built his first aircraft in Leeds in 1908 with the company's Olympia Works at Roundhay opening in 1914. The Blackburn Aeroplane & Motor Company
390-507: The first Cirrus engine, and the first air-cooled four-cylinder inline aero engine, to go into quantity production. The Cirrus was launched onto the market in the de Havilland Cirrus Moth , first in a long line of Moths, in 1925. The engine proved to be ideal for private light aircraft and it created a new era of private flying in the UK, in both the Cirrus Moth and other similar aircraft. It was simple enough to be understood and looked after by
416-583: The owner of London Air Park in Hanworth near Feltham, plus adjoining industrial premises built in 1917 by Whitehead Aircraft Ltd. In early 1935, the Croydon production facilities were transferred to the Hanworth site. Production then restarted with the Monospar ST-12, Monospar ST-18, and Monospar ST-25. In 1936, GAL received an order to build 89 Hawker Fury IIs ; this was followed by other subcontract work including
442-600: The previous inverted engines, with the Minor in the 70-80 hp class and the Major giving 125 hp in normal use. Coming to the market almost together in 1935, they rationalised and replaced the previous ranges. Once the new Cirrus engines were established, in 1937 the company became the Cirrus Engine Division of Blackburn, which itself had been incorporated into Blackburn Aircraft Limited . The Blackburn Cirrus Midget
468-476: The private owner, while its reliability made private flying safe for the first time. Moreover it achieved these at an affordable cost. The uprated Cirrus II, with slightly greater displacement, delivered 75 horsepower (56 kW) from 1926. Halford ended his association with ADC at the end of the year, but development continued. The Cirrus III was introduced in 1928 with even greater displacement and power of 85 horsepower (63 kW). As ADC began to run out of
494-483: The room or capacity to produce the aircraft in quantity, and approached Blackburn Aircraft Ltd , that was looking for work to keep its factory at Brough Aerodrome busy. On 1 January 1949, this led to the two companies merging to form the Blackburn and General Aircraft Ltd . The first GAL.60 was transported by road from Hanworth to Brough and chief test pilot Harold 'Tim' Wood made its first flight there on 20 June 1950, and
520-578: Was a smaller version developed in 1938 but it failed to enter production. During and after WWII Blackburn produced uprated versions of the Cirrus Minor and Major. In 1948 it introduced the Blackburn Cirrus Bombardier with fuel injection and a higher compression ratio, giving increased output. When Blackburn Aircraft merged with General Aircraft Limited (GAL) in 1949, becoming Blackburn & General Aircraft Limited, it continued to market
546-528: Was created in 1914 and established in a new factory at Brough , East Riding of Yorkshire in 1916. Robert's brother Norman Blackburn later became managing director. Blackburn acquired the Cirrus-Hermes Engineering company in 1934, beginning its manufacture of aircraft engines. However an updated range of engines was under development and Blackburn wanted to wait until it was established before giving its name to them, so Cirrus Hermes Engineering
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#1733066171111572-699: Was dropped completely in 1963. An American company, Blackburn Aircraft Corp., was incorporated in Detroit on 20 May 1929 to acquire design and patent rights of the aircraft of Blackburn Airplane & Motor Co., Ltd. in the USA. It was owned 90% by Detroit Aircraft Corp. and 10% by Blackburn Airplane & Motor Co., Ltd. Agreements covered such rights in North and South America, excepting Brazil and certain rights in Canada and provided that all special tools and patterns were to be supplied by
598-508: Was rated at 95 horsepower (71 kW) at 2100 revolutions per minute. The company became known as the A.C.E. Corporation. A new range of 95 horsepower (71 kW) inverted engines was branded Hi-Drive and appeared under names such as the Hi-Drive Cirrus III and Hi-Drive Ensign. The Hi-Drive was supplied in direct and geared drive options, and was designed to accept a de Palma supercharger for increased performance. In 1935 A.C.E.
624-540: Was renowned for its reliability. De Havilland realised that half of this engine would make an air-cooled four-cylinder inline engine of just the right size and at low cost. He persuaded Halford to undertake its design and development. The cylinders, pistons, con-rods and gearing were taken from the Renault, with the valve gear based on the Airdisco , and a new five-bearing crankshaft and cast crankcase were designed. Developing 60 horsepower (45 kW) in normal flight it became
650-569: Was retained as a separate company for the time being. The company's name was changed to Blackburn Aircraft Limited in 1936. In 1937, with the new Cirrus engines now well established, engine manufacturing was brought into the parent company as an operating division, giving rise to the Blackburn Cirrus name. By 1937, pressure to re-arm was growing and the Yorkshire factory was approaching capacity. A fortuitous friendship between Maurice Denny , managing director of William Denny and Brothers ,
676-505: Was taken over by Menasco , who developed the inverted engine as the Pirate , sold from 1936, and a six-cylinder derivative as the Buccaneer . The independent Cirrus-Hermes Engineering Company was formed in 1931. The Hermes models I, II, III and IV were produced ranging in power from 105 hp to 140 hp depending on type. While the Hermes II and III were uprights like their predecessors,
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