The Turbo-Union RB199 is a

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 ...

jet engine A jet engine is a type of reaction engine, discharging a fast-moving jet (fluid), jet of heated gas (usually air) that generates thrust by jet propulsion. While this broad definition may include Rocket engine, rocket, Pump-jet, water jet, and ...

designed and built in the early 1970s by Turbo-Union, a joint venture between

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 ...

, MTU and Aeritalia. The only production application was the

Panavia Tornado The Panavia Tornado is a family of twin-engine, variable-sweep wing multi-role combat aircraft, jointly developed and manufactured by Italy, the United Kingdom and Germany. There are three primary #Variants, Tornado variants: the Tornado IDS ...

, but it was used in the British Aerospace EAP whose 1st flight was on 8 August 1986 from Warton, without use of a spare engine on its total 259 flights, and is now in RAF Cosford Museum. It was also used in the first two Prototypes of the Eurofighter Typhoon, whose 1st flight, by DA1, was from Manching, Bavaria on 27 March 1994, and for a further two years before the EJ200 engines were installed - good reliability meant the spare RB199 engine supplied was never used.

Design and development

The RB199 originated with a requirement, in 1969, to power a new European multirole combat aircraft (MRCA) called the Panavia MRCA. The engine requirements to meet the Panavia MRCA specification were significant advances over current engines in thrust-to-weight ratio, fuel consumption and size. The final selection of the engine for the MRCA was made between a new European collaboration, Turbo Union, with the RB199, and Pratt & Whitney who proposed the JTF16. The Panavia MRCA would later be called the

. Advanced engine studies at Bristol Siddeley had already been done to support the BAC/Dassault AFVG and were based on the Pegasus two-spool arrangement. At

, where the three-shaft RB211 engine was in development, three shafts were considered better. Rolls-Royce took over Bristol Siddeley in 1967 so the configuration for the RB199 was decided, a three-shaft engine, but fundamentally to Bristol's design and Bristol's higher technology. The overall design concept for the international collaborative program, three shafts was decided by Rolls-Royce. The bypass ratio was chosen for long-range, with low fuel consumption, particularly when throttled back. The selected BPR also gave a higher reheat boost than with smaller values used on similar engines. The design of the individual modules was shared between Rolls-Royce, MTU and Fiat according to their existing expertise. Rolls-Royce designed the fan using scaled-down Pegasus knowledge, the combustor, the high pressure (HP) turbine and the

reheat An afterburner (or reheat in British English) is an additional combustion component used on some jet engines, mostly those on military aircraft, military supersonic aircraft. Its purpose is to increase thrust, usually for supersonic flight, ta ...

. The reheat used cold air combustion techniques, described by Arthur Sotheran and which were derived from their experience with ramjets and plenum chamber burning (PCB) in Pegasus front nozzles. Fiat had built turbines for the Viper so designed the low pressure (LP) turbine as well as the final nozzle. MTU designed the intermediate pressure(IP) and high pressure (HP) compressors, the IP turbine, and the thrust reverser. An interesting read from MTU's very early RB199 days can be found in https://aeroreport.de/en/aviation/rb199-development-the-engine-that-started-it-all. A three-spool arrangement reduces the pressure ratio on each compressor so no variable stators were needed. To meet the short afterburner requirement an arrangement known as mix-then-burn, as used in current engines, was not possible because it was too long and heavy. The RB199 used a much shorter arrangement known as mix/burn. The RB199 first ran on 27 September 1971 at Patchway, UK. It was flight-tested using an

Avro Vulcan The Avro Vulcan (later Hawker Siddeley Vulcan from July 1963) was a jet-powered, tailless, delta-wing, high-altitude, strategic bomber, which was operated by the Royal Air Force (RAF) from 1956 until 1984. Aircraft manufacturer A.V. Roe ...

with the engine installed in a

nacelle A nacelle ( ) is a streamlined container for aircraft parts such as Aircraft engine, engines, fuel or equipment. When attached entirely outside the airframe, it is sometimes called a pod, in which case it is attached with a Hardpoint#Pylon, pylo ...

that was representative of the Tornado aircraft. The Vulcan first flew with the RB199 in 1972. Service flying with the Royal Air Force, German Navy and German and Italian Air Forces in the European environment showed normal failure mechanisms for turbine blades,

thermal fatigue A thermal column (or thermal) is a rising mass of buoyant air, a convective current in the atmosphere, that transfers heat energy vertically. Thermals are created by the uneven heating of Earth's surface from solar radiation, and are an example ...

, creep and high cycle fatigue ( HCF) so development started on replacing the initial production equiaxed blades with single-crystal ones which last longer at high temperatures. Sand ingestion tests had been done and passed as part of the qualification for service introduction but operating in desert conditions with the Royal Saudi Air Force produced new problems. Frequent flying in air carrying different sizes of sand particles caused deposits on the HP turbine blades from sand passing through the combustor. In addition, sand carried with the cooling air through the blades blocked the cooling holes. Single crystal blades were being introduced to improve the life of the blades for the European operating conditions and revised cooling hole arrangements were introduced at the same time to reduce the detrimental effect of sand on blade cooling. With incorporation of these blade processing and cooling changes "Desert Storm Tornado aircraft flew some of the most arduous missions of any Allied aircraft with reliability no worse than peacetime and no engines were rejected for HP Turbine blade defects." Looking back on the RB199 program in 2002 Chief Engineer for the RB199, Dr.Gordon Lewis, concluded "The final production standard provided satisfactory reliability and performance."

Variants and applications

;RB199 Mk 101 :Initial variant powered first Tornado IDS deliveries, with a 38.7kN (8700lbf) dry thrust, 66.01kN (14840lbf) with afterburner.Taylor 1996, pp. 610–611 ;RB199 Mk 103 :Powering Tornado IDS strike versions, with a thrust rating of 40.5 kN (dry) 71.2 kN (reheat) ;RB199 Mk 104 :Powering the Tornado F3 Air Defence Variant, with a thrust rating of 40.5 kN (dry) 73 kN (reheat) ;RB 199 Mk104D :Derivative used on the BAe EAP. ;RB199 Mk 105 :Powering Tornado ECR versions and applicable to IDS, with a thrust rating of 42.5 kN (dry) 74.3 kN (reheat) ;RB199-122 :A derivative of the Mk104 (originally designated Mk 104E), powering the first two prototypes of the Eurofighter Typhoon (DA1 and DA2) until the initial versions of the Eurojet EJ200 were available.

Engines on display

*A Turbo-Union RB199 is on public display at the Royal Air Force Museum Cosford and Brooklands Museum Weybridge. *A Turbo-Union RB199 is on public display at the Morayvia Centre in Kinloss. *A Turbo-Union RB199 is on public display at the Montrose Air Station Museum * A Turbo-Union RB199 Mk.103 is on public display at the City of Norwich Aviation Museum in Horsham St Faith, Norfolk. * An RB199 Mk 101 and an RB199 Mk104 are on display in the Deutsches Museum - Flugwert Schleissheim near Munchen.

Specifications (RB199-104)

References

;Notes ;Bibliography *

External links