The Fairey P.24 Monarch was a British experimental 2,000 hp (1,490 kW) class H-24

aircraft engine An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Most aircraft engines are either piston engines or gas turbines, although a few have been rocket powered and in recent years many ...

designed and built by Fairey in the late 1930s. The engine did not go into production.

Design and development

The P.24 Monarch was a 24-cylinder development of the H-16 layout version of the

Prince A prince is a male ruler (ranked below a king, grand prince, and grand duke) or a male member of a monarch's or former monarch's family. ''Prince'' is also a title of nobility (often highest), often hereditary, in some European states. Th ...

, designed by chief engine designer Captain A.G. Forsyth. Similar in layout to the

Napier Dagger The Napier Dagger was a 24-cylinder H-pattern ''(or H-Block)'' air-cooled engine designed by Frank Halford and built by Napier before World War II. It was a development of the earlier Napier Rapier. Design and development The H-Block has a ...

, the

cylinders A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base. A cylinder may also be defined as an infini ...

were arranged vertically in two blocks, driving

contra-rotating propeller Aircraft equipped with contra-rotating propellers, also referred to as CRP, coaxial contra-rotating propellers, or high-speed propellers, apply the maximum power of usually a single piston or turboprop engine to drive a pair of coaxial propell ...

s using separate shafts and gears. Like the smaller Prince engine, one bank of cylinders could be stopped in flight with the other still driving its own propeller, an idea that was reused much later in the

Armstrong Siddeley Double Mamba The Armstrong Siddeley Double Mamba is a turboprop engine design developed in the late 1940s of around . It was used mostly on the Fairey Gannet anti-submarine aircraft developed for the Fleet Air Arm of the Royal Navy. Design and development ...

turboprop A turboprop is a turbine engine that drives an aircraft propeller. A turboprop consists of an intake, reduction gearbox, compressor, combustor, turbine, and a propelling nozzle. Air enters the intake and is compressed by the compressor. Fuel ...

. The idea came from the desire to deliver twin-engine power with twin-engine reliability in a single engine installation for naval use. A twin-engined aircraft would take up more space on an aircraft carrier. With two power blocks a failure in one of them would not necessarily lead to complete loss of engine power. The engine was test flown in a

Fairey Battle The Fairey Battle is a British single-engine light bomber that was designed and manufactured by the Fairey Aviation Company. It was developed during the mid-1930s for the Royal Air Force (RAF) as a monoplane successor to the Hawker Hart and Hi ...

, serial ''K9370'', with its first flight taking place on 30 June 1939. The engine was considered for use in the

Hawker Tornado The Hawker Tornado was a British single-seat fighter aircraft design of the Second World War for the Royal Air Force as a replacement for the Hawker Hurricane. The planned production of Tornados was cancelled after the engine it was designed to ...

and ''K9370'' was later shipped to

Wright Field Wilbur Wright Field was a military installation and an airfield used as a World War I pilot, mechanic, and armorer training facility and, under different designations, conducted United States Army Air Corps and Air Forces flight testing. Loca ...

in the US, where testing (Project MX-229) was carried out in 1942 with a view to using the potentially 3,000 hp of the P.24 in the

Republic P-47 Thunderbolt The Republic P-47 Thunderbolt is a World War II-era fighter aircraft produced by the American company Republic Aviation from 1941 through 1945. It was a successful high-altitude fighter and it also served as the foremost American fighter-bombe ...

, a total of around 250 hours of test flying in the Battle being completed at Wright Field before the idea was abandoned. Following cancellation, the engine provided three trouble-free years of service in ''K9370''."World Encyclopedia of Aero Engines - 5th edition" by

Bill Gunston Bill Gunston (1 March 1927 – 1 June 2013) was a British aviation and military author. He flew with Britain's Royal Air Force from 1945 to 1948, and after pilot training became a flying instructor. He spent most of his adult life doing research ...

, Sutton Publishing, 2006, P.71

Applications

Projected applications

P-47 Thunderbolt The Republic P-47 Thunderbolt is a World War II-era fighter aircraft produced by the American company Republic Aviation from 1941 through 1945. It was a successful high-altitude fighter and it also served as the foremost American fighter-bombe ...

Specifications (P.24 Monarch)

References

Notes

Bibliography

* Gunston, Bill. ''World Encyclopedia of Aero Engines''. Cambridge, England. Patrick Stephens Limited, 1989. * Lumsden, Alec. ''British Piston Engines and their Aircraft''. Marlborough, Wiltshire: Airlife Publishing, 2003. .

External links

Report on the P-24 by Experimental Engineering Section of the Power Plant Laboratory at Wright Field USA

US report on engineering considerations

US report on dual propeller
{{Fairey aeroengines

Monarch A monarch is a head of stateWebster's II New College DictionarMonarch Houghton Mifflin. Boston. 2001. p. 707. Life tenure, for life or until abdication, and therefore the head of state of a monarchy. A monarch may exercise the highest authority ...

1930s aircraft piston engines H engines