The Rolls-Royce Spey (company designations RB.163 and RB.168 and RB.183) is a low-bypass

turbofan A turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft engine, aircraft propulsion. The word "turbofan" is a combination of references to the preceding generation engine technology of the turbojet and the add ...

engine originally designed and manufactured by

Rolls-Royce Rolls-Royce (always hyphenated) may refer to: * Rolls-Royce Limited, a British manufacturer of cars and later aero engines, founded in 1906, now defunct Automobiles * Rolls-Royce Motor Cars, the current car manufacturing company incorporated in ...

that has been in widespread service for over 40 years. A co-development version of the Spey between Rolls-Royce and Allison in the 1960s is the Allison TF41. Intended for the smaller civilian

jet airliner A jet airliner or jetliner is an airliner powered by jet engines (passenger jet aircraft). Airliners usually have twinjet, two or quadjet, four jet engines; trijet, three-engined designs were popular in the 1970s but are less common today. Air ...

market when it was being designed in the late 1950s, the Spey concept was also used in various military engines, and later as a

turboshaft A turboshaft engine is a form of gas turbine that is optimized to produce shaft horsepower rather than jet thrust. In concept, turboshaft engines are very similar to turbojets, with additional turbine expansion to extract heat energy from the ex ...

engine for ships known as the Marine Spey, and even as the basis for a new civilian line, the Rolls-Royce RB.183 Tay. Aviation versions of the base model Spey have accumulated over 50 million hours of flight time. In keeping with Rolls-Royce naming practices, the engine is named after the River Spey.

Design and development

In 1954 Rolls-Royce introduced the first commercial bypass engine, the Rolls-Royce Conway, with 17,500 lbf (78 kN) of thrust aimed at what was then the "large end" of the market. This was far too large for smaller aircraft such as the Sud Caravelle,

BAC One-Eleven The BAC One-Eleven (BAC-111, BAC 1-11) is a retired early jet airliner produced by the British Aircraft Corporation (BAC). Conceived by Hunting Aircraft as a 30-seat jet, before its merger into BAC in 1960, it was launched as an 80-seat airl ...

or Hawker Siddeley Trident which were then under design. Rolls-Royce then started work on a smaller engine otherwise identical in design derived from the larger RB.140/141 Medway - which itself had been cancelled after British European Airways (BEA) had demanded the downsizing of the Trident,"World Encyclopedia of Aero Engines - 5th edition" by Bill Gunston, Sutton Publishing, 2006, p.197 the RB.163, using the same two-spool compressor arrangement and a smaller fan delivering

bypass ratio The bypass ratio (BPR) of a turbofan engine is the ratio between the mass flow rate of the bypass stream to the mass flow rate entering the core. A 10:1 bypass ratio, for example, means that 10 kg of air passes through the bypass duct for eve ...

s of about 0.64:1. Designed by a team under Frederick Morley, the first versions of what had become the 'Spey' entered service in 1964, powering both the 1-11 and Trident. Several versions with higher power ratings were delivered through the 1960s, but development was ended nearing the 1970s due to the introduction of engines with much higher bypass ratios, and thus better fuel economy. In 1980, Turbomecanica

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acquired the license for the Spey 512-14 DW version, which propelled the Romanian built

aircraft (Rombac One-Eleven). Spey-powered airliners remained in widespread service until the 1980s, when noise limitations in European airports forced them out of service.

Tailored for the Buccaneer and Corsair II

In the late 1950s the

Soviet Union The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

started the development of the Sverdlov-class cruisers that would put the

Royal Navy The Royal Navy (RN) is the naval warfare force of the United Kingdom. It is a component of His Majesty's Naval Service, and its officers hold their commissions from the King of the United Kingdom, King. Although warships were used by Kingdom ...

at serious risk. The Naval Air Warfare Division decided to counter this threat with a strike aircraft which would fly at very high speed at very low level. The winning design was the

Blackburn Buccaneer The Blackburn Buccaneer is a British aircraft carrier, carrier-capable attack aircraft designed in the 1950s for the Royal Navy (RN). Designed and initially produced by Blackburn Aircraft at Brough Aerodrome, Brough, it was later officially k ...

The first version of the Buccaneer, the S.1 powered by the de Havilland Gyron Junior, was underpowered in certain scenarios, although not in maximum speed, and the engine was unreliable. The Spey was chosen in 1960 as a re-engining option to give more thrust for a Buccaneer Mk.2. It was also predicted to increase range by 80%. The engine was a militarized version of the BAC 1-11 Spey, and called the RB.168-1. The Buccaneer S.2 served into the 1990s. A Spey derivative, designed and developed jointly by Rolls-Royce and Allison for the

LTV A-7 Corsair II The LTV A-7 Corsair II is an American carrier-capable subsonic light attack aircraft designed and manufactured by Ling-Temco-Vought (LTV). The A-7 was developed during the early 1960s as replacement for the Douglas A-4 Skyhawk. Its design was ...

, was produced under licence in the United States as the TF41.

F-4K and M Phantom

The British versions of the

McDonnell Douglas F-4 Phantom II The McDonnell Douglas F-4 Phantom II is an American tandem two-seat, twin-engine, all-weather, long-range supersonic jet interceptor and fighter-bomber that was developed by McDonnell Aircraft for the United States Navy.Swanborough and Bower ...

(designated Phantom FG.Mk.1 and FGR.Mk.2) replaced the 16,000 lb wet thrust J79 turbojets with a pair of 20,515 lb wet thrust Spey 201 turbofans. These provided extra thrust for operation from smaller British aircraft carriers, and provided additional bleed air for the boundary layer control system for slower landing speeds. The air intake area was increased by twenty per cent, while the aft fuselage under the engines had to be redesigned. Compared to the original turbojets, the afterburning turbofans produced a ten and fifteen per cent improvement in combat radius and ferry range, respectively, and improved take-off, initial climb, and acceleration, but at the cost of a reduction in top speed because compressor outlet temperatures would be exceeded in an essentially subsonic civil design.

Reliability

During its lifetime the Spey has achieved an impressive safety record. Its relatively low maintenance costs provide one of the major reasons it remained in service even when newer designs were available. With the need for a 10,000 to 15,000 lbf (44 to 67 kN) thrust class engine, with better specific fuel consumption and lower noise and emission levels, Rolls-Royce used Spey turbomachinery with a much larger fan to produce the Rolls-Royce Tay.

AMX development

A fully updated version of the military RB.168 was also built to power the AMX International AMX attack aircraft.

Variants

;RB.141: ;RB.163-1: ;RB.163-2: ;RB.163-2W: ;RB.163 Mk.505-5: ;RB.163 Mk.505-14: ;RB.163 Mk.506-5: ;RB.163 Mk.506-14: ;RB.163 Mk.511-8: Gulfstream II and

Gulfstream III The Gulfstream III, a business jet produced by Gulfstream Aerospace, is an improved development of the Grumman Gulfstream II. The U.S. military uses versions of the Gulfstream III as the C-20A/B/C/D/E aircraft, though later C-20 F/G/H/J are Gu ...

(USAF designation F113-RR-100 for the Gulfstream C-20) ;RB.163 Mk.511-14:

;RB.163 Mk.512-14DW: BAC One-Eleven/Rombac One-Eleven ;AR 963: (RB.163)

Boeing 727 The Boeing 727 is an American Narrow-body aircraft, narrow-body airliner that was developed and produced by Boeing Commercial Airplanes. After the heavier Boeing 707, 707 quad-jet was introduced in 1958, Boeing addressed the demand for shorter ...

(proposed); it was to have been built under licence by Allison ;RB.168-62: ;RB.168 Mk.101: (Military Spey)

S2 ;RB.168 Mk.202: (Military Spey)

modified F-4J for British service ("Phantom FG1"). (Surplus engines were purchased and used by Richard Noble for the Thrust SSC land speed record car of 1997.) ;RB.168 Mk.250: (Military Spey) Hawker Siddeley Nimrod MR1/MR2 ;RB.168 Mk.251: (Military Spey) Hawker Siddeley Nimrod R1 and AEW ;RB.168 Mk.807: AMX International AMX, built under licence by FiatAvio ;AR 168R: Joint development with

Allison Engine Company The Allison Engine Company was an American aircraft engine manufacturer. Shortly after the death of James A. Allison, James Allison in 1929 the company was purchased by the Fisher Body, Fisher brothers. Fisher sold the company to General Motors ...

for the TFX competition (won by the

Pratt & Whitney TF30 The Pratt & Whitney TF30 (company designation JTF10A) is a military low-bypass turbofan engine originally designed by Pratt & Whitney for the subsonic F6D Missileer fleet defense fighter, but this project was cancelled. It was later adapted with ...

;RB.183 Mk 555-15 Spey Junior:

Fokker F28 Fellowship The Fokker F28 Fellowship is a twin-engined, short-range jet airliner designed and built by Netherlands, Dutch aircraft manufacturer Fokker. Following the Fokker F27 Friendship, an early and commercially successful turboprop-powered regional air ...

;WS-9 Qinling: Chinese license-produced version of the RB.168 Mk.202 manufactured by the Xi'an Aero-Engine Corporation, which was exported in 1975 violating the COCOM restrictions. It was used to power the Xian JH-7 and JH-7A. An improved WS-9A developing of thrust is reportedly in development.