Pobjoy Airmotors and Aircraft was a British

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 manufacturer of small aircraft engine

Aircraft engine

An aircraft engine is the component of the propulsion system for an aircraft that generates mechanical power. Aircraft engines are almost always either lightweight piston engines or gas turbines...

s. The company was purchased by Short Brothers

Short Brothers

Short Brothers plc is a British aerospace company, usually referred to simply as Shorts, that is now based in Belfast, Northern Ireland. Founded in 1908, Shorts was the first company in the world to make production aircraft and was a manufacturer of flying boats during the 1920s, 1930s, and 1940s...

 shortly before the start of World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, production continuing until the end of the war.

History

Douglas Rudolf Pobjoy started in the engine business working with Roy Fedden

Roy Fedden

Sir Alfred Hubert Roy Fedden MBE was an engineer who designed most of Bristol Engine Company's successful aircraft engine designs.-Early life:...

 at Cosmos Engineering

Cosmos Engineering

Cosmos Engineering was a company that manufactured aero-engines in a factory in Fishponds, Bristol during World War I. Sir Roy Fedden, the company's principal designer, developed the 14-cylinder radial Mercury engine during this period...

 just after the end of World War I

World War I

World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

. Cosmos went bankrupt shortly after the war, and its assets were picked up by the Bristol Aeroplane Company

Bristol Aeroplane Company

The Bristol Aeroplane Company, originally the British and Colonial Aeroplane Company, was both one of the first and one of the most important British aviation companies, designing and manufacturing both airframes and aero engines...

, where Fedden would go on to produce a line of extremely successful engines.

Pobjoy also spent time in the RAF

Royal Air Force

The Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...

 as an education officer. Here he met Flt. Lt. Nicholas Comper

Nicholas Comper

Nicholas Comper was an English aviator and aircraft designer, whose most notable success was the 1930s Comper Swift monoplane racer.-Early life:...

 who went on to design the Comper Swift

Comper Swift

-See also:-References:*Boughton, Terence. 1963. The Story of The British Light Aeroplane. John Murray*Meaden, Jack & Fillmore, Malcolm. . The Comper Lightplanes. Air-Britain Archive . Air-Britain. ISSN 02624923...

, that would later fly from London to Australia in 9 days 2 hours. Pobjoy partnered with Parnall

Parnall

Parnall was a British aircraft manufacturer, that evolved from a wood-working company before the First World War to a significant designer of military and civil aircraft into the 1940s. It was based in the west of England.-History:...

 to develop an engine for the Swift. Although they felt that a cast-block inline engine like the ones being produced by Cirrus

Cirrus Engine

Cirrus Aero-Engines Limited was a British aircraft engine manufacturer, known for their line of 4-cylinder air-cooled vertical inline engines for general aviation use. The company traded between 1927 and 1931.-History:...

 and de Havilland

De Havilland

The de Havilland Aircraft Company was a British aviation manufacturer founded in 1920 when Airco, of which Geoffrey de Havilland had been chief designer, was sold to BSA by the owner George Holt Thomas. De Havilland then set up a company under his name in September of that year at Stag Lane...

 would always be less expensive, they nevertheless selected the radial

Radial engine

The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders point outward from a central crankshaft like the spokes on a wheel...

 layout for their design, feeling that the cost would be more than offset by the lighter weight and higher performance his designs would offer. Douglas Pobjoy later took over the design, and started a company of his own to produce it at Hooton Park

Hooton Park

RAF Hooton Park, on the Wirral Peninsula, Cheshire, was a Royal Air Force station originally built for the Royal Flying Corps in 1917 as a training aerodrome for pilots in World War I. During the early/mid 1930s, it was one of the two airfields handling scheduled services for the Merseyside...

 in the Wirral

Wirral Peninsula

Wirral or the Wirral is a peninsula in North West England. It is bounded by three bodies of water: to the west by the River Dee, forming a boundary with Wales, to the east by the River Mersey and to the north by the Irish Sea. Both terms "Wirral" and "the Wirral" are used locally , although the...

.

The Parnall/Pobjoy design, the 7-cylinder 67 hp Pobjoy P, received its 50-hour type rating in 1928. This was followed in 1929 by the 75/80 hp Pobjoy R

Pobjoy R

|-See also:-Bibliography:* Guttery, T.E. The Shuttleworth Collection. London: Wm. Carling & Co, 1969. SBN 901319-01-5* Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6....

, that became very successful, notably on the General Aircraft Monospar

General Aircraft Monospar

-Bibliography:*The Illustrated Encyclopedia of Aircraft . Orbis Publishing, 1985, p. 2158.*Jackson, A.J. 1973. British Civil Aircraft since 1919, Volume 2. Putnam ISBN 0370100107....

. Later designs included the 85/90 hp Pobjoy Cataract, replacing the Pobjoy R, and the 130 hp Pobjoy Niagara

Pobjoy Niagara

|-See also:-Bibliography:* Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9...

 of 1934. The Niagara was used on a number of designs by Shorts designers, notably the Short Scion Senior

Short Scion Senior

|-See also:-Bibliography:* Barnes, C.H. with revisions by Derek N. James. Shorts Aircraft since 1900. London: Putnam, 1989 . ISBN 0-85177-819-4....

 and the original half-scale prototype for the Short Stirling

Short Stirling

The Short Stirling was the first four-engined British heavy bomber of the Second World War. The Stirling was designed and built by Short Brothers to an Air Ministry specification from 1936, and entered service in 1941...

, the S.31. The Niagara's compact size and excellent performance led to it being used on the Air Ministry

Air Ministry

The Air Ministry was a department of the British Government with the responsibility of managing the affairs of the Royal Air Force, that existed from 1918 to 1964...

's S.23/27 extremely long-endurance prototypes, the General Aircraft GAL.38 and Airspeed AS.39 Fleet Shadowers.

In 1934, Pobjoy Airmotors moved its plant to Rochester, Kent, to be closer to its largest customer, Shorts. The move, and the ongoing effects of the Great Depression

Great Depression

The Great Depression was a severe worldwide economic depression in the decade preceding World War II. The timing of the Great Depression varied across nations, but in most countries it started in about 1929 and lasted until the late 1930s or early 1940s...

, drove the company into financial difficulty, and it was eventually bought outright by Shorts.the company was made public in 1935. Douglas Pobjoy then moved on to designing de-icing equipment for high-altitude flights.

During the Second World War, Pobjoy ran a section of Rotol Airscrews

Dowty Rotol

Dowty Rotol is a British engineering company based in Cheltenham specialised in the manufacture of propellers and propeller components. It is owned by General Electric, forming part of its GE Aviation Systems division.-History:...

 of Gloucester, England, and was responsible for the design and development of an airborne generator, intended for use on the Short Shetland

Short Shetland

-See also:-Bibliography:* Barnes, C.H. and James, D.N. Shorts Aircraft since 1900. London, Putnam, 1989. ISBN 0-85177-819-4.* Bowyer, Michael J.F. Aircraft for the Royal Air Force: The "Griffon" Spitfire, The Albemarle Bomber and the Shetland Flying-Boat. London: Faber & Faber Ltd., 1980. ISBN...

 flying boat. The unit consisted of a flat-six sleeve-valve air-cooled petrol engine driving the generator. This was installed inboard on the aircraft, and due to the incorrect closure of the cooling ducts the engine overheated and the resulting fire destroyed the prototype Shetland. It seems that the project was abandoned at this stage.

After the war Pobjoy designed a new tractor. On 4 July 1948, he was returning from a sales trip to Helsinki

Helsinki

Helsinki is the capital and largest city in Finland. It is in the region of Uusimaa, located in southern Finland, on the shore of the Gulf of Finland, an arm of the Baltic Sea. The population of the city of Helsinki is , making it by far the most populous municipality in Finland. Helsinki is...

 when the Scandinavian Airlines Douglas DC-6

Douglas DC-6

The Douglas DC-6 is a piston-powered airliner and transport aircraft built by the Douglas Aircraft Company from 1946 to 1958. Originally intended as a military transport near the end of World War II, it was reworked after the war to compete with the Lockheed Constellation in the long-range...

 he was flying in collided with an Avro York

Avro York

The Avro York was a British transport aircraft that was derived from the Second World War Lancaster heavy bomber, and used in both military and airliner roles between 1943 and 1964.-Design and development:...

 in clouds over RAF Northolt

RAF Northolt

RAF Northolt is a Royal Air Force station situated in South Ruislip, east by northeast of Uxbridge in the London Borough of Hillingdon, West London. Approximately north of London Heathrow Airport, the station also handles a large number of private civil flights...

. All 38 passengers in both aircraft were killed.

Engine designs

• Pobjoy P (1928)

7-cylinder radial, air-cooled, geared, 2,480 cc, 67 hp (50 kW)

• Pobjoy R
  Pobjoy R
  |-See also:-Bibliography:* Guttery, T.E. The Shuttleworth Collection. London: Wm. Carling & Co, 1969. SBN 901319-01-5* Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6....
  
   (1933)

7-cylinder radial, air-cooled, geared, 2,835 cc, 85 hp (63 kW)

• Pobjoy Cataract I-III (1934-6)

7-cylinder radial, air-cooled, geared, 2,835 cc, three marks with take-off powers from 80-98 hp (60-73 kW)

• Pobjoy Cascade (1934)

7-cylinder radial, air-cooled, direct drive version of Cataract I, 2,835 cc, take-off power 70 hp (52 kW)

• Pobjoy Niagara I-IV
  Pobjoy Niagara
  |-See also:-Bibliography:* Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9...
  
   (1936-7)

7-cylinder radial, air-cooled, geared, cowled, 2,835 cc, four marks with take-off powers from 84-98 hp (63-73 kW)

• Pobjoy Niagara V
  Pobjoy Niagara
  |-See also:-Bibliography:* Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9...
  
  (1937)

7-cylinder radial, air-cooled, geared, cowled, 3,138 cc cc, take-off power 142 hp (106 kW)