The Rolls-Royce RB.93 Soar, also given the Ministry of Supply designation RSr., was a small, expendable

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies. ** Britishness, the British identity and common culture * British English, ...

axial-flow An axial compressor is a gas compressor that can continuously pressurize gases. It is a rotating, airfoil-based compressor in which the gas or working fluid principally flows parallel to the axis of rotation, or axially. This differs from othe ...

turbojet The turbojet is an airbreathing jet engine which is typically used in aircraft. It consists of a gas turbine with a propelling nozzle. The gas turbine has an air inlet which includes inlet guide vanes, a compressor, a combustion chamber, and ...

intended for

cruise missile A cruise missile is a guided missile used against terrestrial or naval targets that remains in the atmosphere and flies the major portion of its flight path at approximately constant speed. Cruise missiles are designed to deliver a large warhe ...

use and built by

Rolls-Royce Limited Rolls-Royce was a British luxury car and later an aero-engine manufacturing business established in 1904 in Manchester by the partnership of Charles Rolls and Henry Royce. Building on Royce's good reputation established with his cranes, they ...

in the 1950s and 1960s. Like all the company's gas turbine engines it was named after a British river, in this case, the

River Soar The River Soar () is a major tributary of the River Trent in the English East Midlands and is the principal river of Leicestershire. The source of the river is midway between Hinckley and Lutterworth. The river then flows north through Leicest ...

Design and development

The Soar was developed in the early 1950s, and was demonstrated at the

Farnborough Airshow The Farnborough Airshow, officially the Farnborough International Airshow, is a trade exhibition for the aerospace and defence industries, where civilian and military aircraft are demonstrated to potential customers and investors. Since its fir ...

in 1953 on each wingtip of a

Gloster Meteor The Gloster Meteor was the first British jet fighter and the Allies of World War II, Allies' only jet aircraft to engage in combat operations during the Second World War. The Meteor's development was heavily reliant on its ground-breaking turb ...

flying testbed. It was the smallest aero-engine ever made by Rolls-Royce and was an extremely simple engine with very few parts. Its starting and control systems were almost non-existent. Lessons learned in producing the Soar at low weight and cost would be applied to the next light-weight engine, the RB108 lift engine. As a cruise-missile expendable powerplant the Soar engine had a design life of 10 hours for a Red Rapier flight time of about 1 hour (range 400 nautical miles at 475 knots).

Applications

It was to be the intended powerplant for the "Red Rapier" missile project one of the projects coming from the

UB.109T UB.109T, better known as Red Rapier, was a British cruise missile project calling for a system able to deliver a 5,000 lb (2.27 tonne) conventional warhead within 100 yards of its target at over range while travelling at at . The con ...

operational requirement. Red Rapier was to be built by

Vickers-Armstrong Ltd Vickers-Armstrongs Limited was a British engineering conglomerate formed by the merger of the assets of Vickers Limited and Sir W G Armstrong Whitworth & Company in 1927. The majority of the company was nationalised in the 1960s and 1970s, wi ...

Weybridge Weybridge () is a town in the Borough of Elmbridge in Surrey, England, around southwest of central London. The settlement is recorded as ''Waigebrugge'' and ''Weibrugge'' in the 7th century and the name derives from a crossing point of the ...

Surrey Surrey () is a ceremonial and non-metropolitan county in South East England, bordering Greater London to the south west. Surrey has a large rural area, and several significant urban areas which form part of the Greater London Built-up Area. ...

as the Vickers 825. Development was cancelled in 1953. Three Soar engines were used on this design, two on the tips of the tailplane, and one on the tip of the fin. One-third scale models without engines were built and air launched from a Washington bomber (the Boeing

B-29 Superfortress The Boeing B-29 Superfortress is an American four-engined propeller-driven heavy bomber, designed by Boeing and flown primarily by the United States during World War II and the Korean War. Named in allusion to its predecessor, the B-17 Fl ...

in RAF service) on the Woomera missile range to test the aerodynamics and autopilot operation. As the Westinghouse J81 it was a powerplant for the US AQM-35 missile US designation systems
/ref> It was employed as an auxiliary powerplant for the Italian

Aerfer Ariete The Aerfer ''Ariete'' (Italian for ''Ram'') was a prototype fighter aircraft built in Italy in 1958. It was a refined derivative of the Aerfer Sagittario 2, and was an attempt to bring that aircraft up to a standard where it could be mass-produc ...

fighter design and also considered as a

JATO JATO (acronym for jet-assisted take-off) is a type of assisted take-off for helping overloaded aircraft into the air by providing additional thrust in the form of small rockets. The term ''JATO'' is used interchangeably with the (more specific ...

powerplant for other aircraft. The Soar project was cancelled in March 1965, at a reported total cost of £1.2 million.

Specifications (RB.93 Soar)

References

Notes

Bibliography

* Gunston, Bill. ''World Encyclopedia of Aero Engines''. Cambridge, England. Patrick Stephens Limited, 1989. * Gunston, Bill. ''Rolls-Royce Aero Engines''. Cambridge, England. Patrick Stephens Limited, 1989.

External links

Image of a Rolls-Royce SoarImage of the same engine from another angle
{{USAF gas turbine engines Soar 1950s turbojet engines