Trust in thriving thrust. (Technology).

Powerplant developments continue to emphasise increased thrust/ weight ratios, reduced mission fuel demands, lower life-cycle costs and improved surge-free control. Major advances are also taking place in the fields of turboprops for military transports and innovative concepts to provide combat aircraft with vertical/short take-off and landing capability, which may become more important as ballistic missiles and weapons of mass destruction proliferate.

Starting this review with fighter engines, one of the most widely used turbojets is the General Electric F404. Over 3700 have been delivered and the series has now accumulated over eight million engine flight hours. The F404 began life with an afterburning thrust of just over 70 kN, making it a suitable basis for single-engined lightweights such as the Gripen (now equipped with the 80 kN RM12 version developed by Volvo Aero) and twin-engined medium combat aircraft such as the F/A-18 Hornet. The top of the General Electric-built range is the 78.73 kN F400-GE-402 Enhanced Performance Engine, originally developed for Kuwait's F/A-18C/D and subsequently fitted to Swiss and US Navy Hornets. A non-afterburning F404 is used in some attack aircraft, as exemplified by the F-117A, which has two 48 kN F404-GE-F1D2s. For the much heavier F/A-18E/F Super Hornet, the F404 series has been replaced with the 98 kN F414-GE-400, which has 16 per cent more mass flow. Mass production began in 1998 and deliveries to the US Navy are planned to continue until at least 2012. The service will buy 1096 F414s for 548 Super Hornets. The F414 has recently been selected for the single-engined Eads Mako advanced trainer and light combat aircraft.

The closest Russian equivalent to the F404 is the 81.4 kN Klimov RD-33 used in the twin-engined MiG-29. It is also scheduled to power the single-engined Chengdu FC-1/Super 7, which is being developed with some assistance from Pakistan, and is due to fly in late_2003. The RD-33 has also been flight tested in a South African Mirage F1C, a number of which are available for export. The current development emphasis is on increasing maintenance intervals and service life. The RD-33 Series 3 will run 1000 hours between overhauls and provide a life of 2000 hours. Later developments of the MiG-29 are expected to see the introduction of the 91.2 kN RD-133 or the 98.1 kN RD-333 (also referred to as the RD-43) with thrust-vectoring. The RD-93 is a derivative proposed for the Chengdu J-10 project, based on the IAI Lavi.

In mechanical terms, the simplest fighter engine is currently the single-shaft Snecma M53 used in the Mirage 2000 series. The latest version is the 95.2 kN M53-P2 that was developed primarily to increase the low level non-after-burning penetration speed of the Mirage 2000N. Recent contracts have included a United Arab Emirates order for 36 M53-P2s for its 30 Mirage 2000-9s. The Snecma M88 engine for the Rafale, on the other hand, adopts a conventional two-shaft layout. The 75 kN M88-2 is the standard powerplant for Rafales in French service, but potential export customers are demanding the 87 kN M88-3, which is being developed at Snecma's expense and is predicted to increase the maximum speed of the Rafale from around Mach 1.8 to 2.0.

The increased thrust of the M88-3 is required to allow the Rafale to compete with the performance of the slightly heavier Typhoon, which is powered by two 89 kN Eurojet EJ200s. The E J200 is produced by Rolls-Royce, MTU-Munich, FiatAvio of Italy and ITP of Spain. It is anticipated that approximately 1500 EJ200s will be required to fulfil the four-nation domestic market for over 600 Typhoons. The EJ200 may also be used in later export Gripens.

Moving to more powerful fighter engines, the Pratt & Whitney Fl00 family equips approximately 68 per cent of all F-16s and all current F-15s. The series began with the 104.3 kN F100-PW-100 for the twin-engined F-15A/B and the 105.7 kN F100-PW-200 for the single-engined F-16A/B. The latest variant is the 144.5 kN F100-PW-232, which is available as an upgrade for fighters equipped with the 129 kN F100-PW-229. Since entering service in 1974, more than 6800 F100s have accumulated over 16 million engine flight hours in the service of 18 nations.

The only direct rival to the F100 is the General Electric F110, which was based on the core of the Fl01 developed for the B-1B bomber, and was first applied to the F-16C/D. The F110 has been adopted for some US Air Force F-16s and the F-16s of six overseas services (as well as Japan's F-2). The 122.8 kN F110-GE-100 was followed by the 129 kN Fl10-GE-129 and most recently by the F110-GE-132, which has been ordered by the United Arab Emirates for its F-16C/D Block 60s; it incorporates a new fan derived from that of the Fl18 used by the B-2 stealth bomber. The -132 may be rated at 144 kN, or derated to 129 kN to double engine life.

The Russian equivalent of the F100/F110 class of engines is the 122.6 kN Saturn/Lyulka AL-31F used in the Su-27 family of heavy fighters. Later variants include the thrust-vectoring AL-31FP (known as the Al-37FU in the case of the Su-37), the marinised 130.4 kN AL-31K for the Su-33, and the increased diameter 137.3 kN AL-31FM (or AL-35F) for the Su-35. The thrust-vectoring 142.2 kN AL-37FU is the production engine for the Indian Air Force Su-30MKI. The AL-41F is believed to be the engine used by the Mikoyan 1-44 and the S-37.

The 155 kN Pratt & Whitney F119-PW-100 powers the twin-engined F-22 air dominance fighter. The first production afterburning engine to have thrust-vectoring, the F119 has a two-dimensional nozzle for short field performance and enhanced manoeuvrability. Its dry thrust is sufficient to allow the F-22 to cruise supersonically.

A modified P&W Fl19 (designated JSF119, or F135 in production form), featuring an increased bypass ratio and revised low-pressure spool, will power at least the first five production batches of the F-35/JSF (Joint Strike Fighter). In the case of the Stovl F-35B version, the low-pressure shaft is linked through a geared clutch to a two-stage, counter-rotating lift-fan installed behind the cockpit. The dutch transmits 21,625 kW, and the fan produces a jet-lift of 90 kN. The jet pipe of the engine incorporates a three-bearing swivel module (3BSM) that can turn the residual thrust down through 95 degrees in 2.5 seconds, producing 80 kN of jet lift. Each of the two roll reaction controls in the wings provides a further 8.7 kN of lift. Rolls-Royce is responsible to P&W for the complete jet-lift system.

Just as General Electric developed the F110 as an alternative to Pratt & Whitney's F100 for the F-15 and F-16, the company is being funded to provide an alternative to the F135 for the JSF/F-35 programme. The resulting F136 is based on the YF120 proposal for the F-22. Rolls-Royce has a 40 per cent interest in the F136 programme, including responsibility for the engine's three-stage fan.

Trainers

With the Hawk continuing to dominate the current trickle of advanced jet trainer sales, the Rolls-Royce/Turbomeca Adour remains in production. Around 2600 Adours have thus far been produced (mainly for the Hawk and the Jaguar), and the type serves with 19 armed forces. The 29 kN Adour 951, developed for the Hawks ordered by South Africa, is also planned to equip the Hawk NGA (New Generation Aircraft), which could be a less expensive alternative to the M-346 as the proposed Eurotrainer. The Adour 900 series introduces Fadec (full authority digital engine control) and a Hums (health and usage monitoring system).

The principal alternative to the Adour is the 28.5 kN Honeywell F124, which is a non-afterburning derivative of the F125 developed for Taiwan's Ching Kuo fighter. The F124 has been selected for the L-159 and M-346 trainers.

For the Russian Federation market, the Yak-130 is expected to be equipped with a domestic alternative to the prototype's Slovak-built PS DV-2, producing a thrust of around 25 kN. This may be the Klimov RD-35 (an improved DV-2), a Saturn/Lyulka AL-55, a Soyuz RD-2500 or an Ivchenko/Progress AI-225-25. The rival MiG-AT will have Snecma Larzacs for export but the domestic version may have the Soyuz RD-1700, the Progress/Motor Sich AI-25TL Series 2 or the Saturn/Lyulka AL-55, These engines are expected to provide a static thrust approaching 20 kN.

In the turboprop trainer category the Pratt & Whitney Canada PT6A series continues to win most sales, although the Honeywell TPE331 series competes at the upper end of the power range. The latest developments in this class of aircraft are the T-6A, the Super Tucano/ALX and the PC-21, all of which use the 1300 kW PT6A-68 series. At the lower end of the turboprop range, around 300 kW, the Rolls-Royce Model 250 continues to dominate, as evidenced by its selection for the new Grob G140TP.

Transports

At the lower end of the transport turbofan spectrum, the CFM International (GE/Snecma) CFM-56-2 entered military service in 1984 with the American designation F108-CF-100. Rated at 98 to 107 kN, it equips the KC-135R, C-135R, E-3, KE-3A, E-6A and DC-8 Super 70. The largest customer is the US Air Force, which has over 450 B707-derived aircraft with CFM56-2 engines already in service.

The 180 kN Pratt & Whitney F117-PW-100 is a military version of the PW2040, and equips the C-17. Over 500 have now been delivered. Further up the scale, the 282 kN PW4062 is one of the engine options for the B767-200ER, and is thus available for the B767 tanker/transport.

The principal alternative engine for the B767 tanker/transport is the 274 kN General Electric CF6-80C2, which has been selected by the launch customer, the Italian Air Force. The CF6 series currently equips approximately 1700 aircraft, which have so far accumulated over 210 million engine flight hours, more than any other high-bypass engine.

Turboprop engines offer special attractions for military transports in providing outstanding cruise economy (with only a small speed penalty relative to high-bypass turbofans) in combination with short take-off and landing performance. The most dramatic advance is promised by the 10,440 kW Ivchenko Progress/Zaporozhye D-27 engines for the An-70, turning Aerosila/Stupino propfans with contra-rotating eight- and six-blade units. The An-70, which first flew in 1994, has had a difficult gestation period, but Russia and the Ukraine have long-term needs for 165 and 65 aircraft respectively, and there are reports that small batches may be produced for the Czech Republic, Hungary and Germany.

In a more conventional category, the 3460 kW Rolls-Royce AE2100D turboprop powers the four-engined C-130J and the twin-engined C-27J. Derived from the 4586 kW AE1107C/T406 turboshaft used by the V-22 tilt-rotor project, the AE2100D has a Lucas Fadec system and turns a six-blade Dowty composite propeller. It is to be applied as an upgrade for the US-1A amphibian, producing the US-1Kai, which is scheduled for service in 2009.

The A400M requires four advanced turboprops in the 10,000 kW category. The principal contenders are a derivative of the Pratt & Whitney Canada PW800 turbofan and the TP400-D6 proposed by EPI Europrop International, representing Rolls-Royce, Snecma, MTU-Munich, ITP and Techspace Aero.

Helicopters

Most of the helicopter market relates to engines producing less than 2000 kW, although there are some far more powerful units, such as the Ukraine's 8500 kW Ivchenko Progress D-136 used in the Mi-26, and Russia's 4100 kW Aviadvigatel/Perm D-25V used in the Mi-6.

One of the most widely used engines is the General Electric T700 (and the corresponding CT7 civil version), which powers 25 helicopter types. Over 12,000 T700/CT7s have been produced for 133 customers in 57 countries. The latest model in service with the US Army is the 1450 kW T700-GE-701C, with applications that include the AH-64D and MH-60G. The corresponding marinised version is the T700-GE-401C, which is used by the HH-60H/J, SH-60B/F and S-70B. Further development of the T700 with FiatAvio has led to the 1520 W T700/T6A for the Italian Navy EH101 and the Cormorant, and the 1865 kW T700/T6E1 for the Italian Navy NH90. The CT7-8 for the S-92 is basically the same engine.

The Rolls-Royce/Turbomeca RTM322 produces between 1565 and 2235 kW, and is one of the engine options for the EH101 and NH90. It also equips British Army AH-64Ds, and is offered for the H-60 family and the S-92. It is estimated that around 1300 RTM322s will be purchased.

The Klimov TV3-117 family, manufactured by Motor Sich, is somewhat older, beginning bench tests in 1974. More than 9700 examples have been produced for 125 customers. Rated at around 1650 kW, it powers helicopters such as the Mi-8, Mi-17 and Mi-24. The uprated 1865 kW TV3-117VMA equips the new Mi-28 and Ka-50/52 attack helicopters and is offered as an alternative to the 2460 kW P&WC PW127T/S for the Mi-38.

The Pratt & Whitney Canada PT6 is one of the world's most successful gas turbine engines, with over 33,500 units delivered as turboshafts or turboprops. The series has accumulated well over 200 million engine flight hours. The turboshaft PT6C and PT6T Twin Pac (US military designation T400) series cover the 1250 to 1500 kW range. Recent examples include the 1250 kW PT6C-67D for the Bell/Agusta AB139 and China's Jingdezhen Z-10 attack helicopter. The PT6T family is used primarily on the UH-1 and AH-1 series and the Bell 212/412.

LHTEC (Light Helicopter Turbine Engine Company) is a joint venture by Honeywell and Rolls-Royce, formed to develop and produce the T800 engine for the RAH-66 Comanche stealthy scout helicopter, of which the US Army originally planned to procure 1213 examples (currently reduced to 650). The RAH-66 first flew in 1996 with the 970 kW T800-LH-800, but demonstrated a need for more power, leading to the 1155 kW T800-LH-801. Production RAH-66s will have the 1195 kW T800-LH-802. The commercial version is the 1015 kW CTS800-4N, which powers the Super Lynx 300 and has been used to re-engine some UH-1s.

The MTR (MTU-Munich/Turbomeca/Rolls-Royce) 390 produces between 960 and 1160 kW. It was initially developed for the Tiger attack helicopter, of which a batch of 160 is being built for France and Germany requiring 320 engines. Deliveries began in early 2002. The Tiger was selected by Australia and it is hoped that Spain will be the second export customer. A new development of the MTR390, one that provides 20 to 25 per cent more power, expected to be available within three years.

The Turbomeca Arriel covers the range 475 to 735 KW. Well over 4800 have so far been produced, accumalating more than twelve million engine flight hours. The 635 kW Arriel 2 introduced Fadec to the series. Applications include the single-engined AS.550 Fennec and the twin-engined AS.565 Panther. The less powerful Turbomeca Arrius series is exemplified by the 360 kW Arrius 1M for the AS.555 Fennec, the 435 kW Arrius 2B for the EC.635 and the 520 kW Arrius 2K2 for the A.109 Power.

The Rolls-Royce Model 250-powers over 170 types of rotary- and fixed-wing aircraft, and produces between 315 and 535 kW. Over 28,500 of these engines have been manufactured, accumulating more than 150 million engine flight hours. Recent applications include the TH-67 Creek training helicopter and the RQ-8A Fire Scout unmanned helicopter.

The P&WC PW206 is a new generation 475 to 530 hp engine that equips the MD Explorer and is an alternative engine for the A.109 Power. A growth version aimed at around 700 kW is being developed.