Guy Norris/LOS ANGELES
Flight International's final turbofan directory of the 20th century reveals the broadest power range and most capable set of engines in the industry's history.
Topping the list are the mighty Boeing 777 powerplants, with GE Aircraft Engines' GE90-115B mentioned as a firm project for the first time. Boeing's mid-1999 decision to select the engine exclusively for the 777-200X/300X, coupled with GE's about-turn on future developments of the world's biggest turbofan, provides a fitting finale to more than 60 years of jet engine development.
Rated at 115,000lb thrust (512kN), the GE90-115B is unlikely to be out-powered by anything else in the commercial world for decades to come. Even the foreseen thrust requirements of the largest Airbus A3XX, Boeing 747-400X Stretch or Large Airplane Product Development projects come nowhere near these power levels.
Looking further ahead, the prospective ultra-efficient airframes of the future, such as blended-wing bodies, are well catered for with current thrust levels. The only engine types expected to break this power barrier are the hybrid turbine and rocket-based combined-cycle propulsion systems under study for hypersonic transports later in the 21st century.
The move to exclusivity with Boeing and GE over the 777X also hinted at intriguing new dynamics in the traditional engine manufacturing triad of GE, Pratt & Whitney and Rolls-Royce. GE, which came close last year to withdrawing from new developments to concentrate on spares, maintenance and minor upgrades, changed the rules by throwing itself back into the 777X competition. By offering substantial financial support to Boeing's programme, it gained an exclusive position at the expense of P&W and R-R, both of which have so far enjoyed the largest market share on the big Boeing twin. Boeing's product development group has since been fighting for market acceptance of its decision, which appears to fly in the face of the "customer-driven" principles that have dominated the 777 programme for so long. With a launch decision apparently imminent, it appears that the gamble may be about to pay off - although this is far from guaranteed as Flight International goes to press.
Even assuming the 777X gets the go-ahead, Boeing and GE may still have to pay a high price. In spite of its de facto exclusivity on the Airbus A340-500/600 family, R-R is confident of raking in business with the Trent 500. The long gestation of the 777X, plus the undeniable technological and psychological challenges of developing such mammoth engines for the big twin, sent many previously loyal Boeing long-haul customers to Airbus. Recent documents revealed to Flight International show continued airline resentment at the exclusivity decision.
One airline told the manufacturer it "wanted P&W, but would have taken R-R before ever considering GE. If we have to take an engine, we just won't take the aeroplane." In technical analysis, two major prospective 777X customers, American Airlines and British Airways, expressed preferences for R-R, while only Air France actively supported GE.
Boeing is fully committed to its decision, and maintains that the GE90's benefits will more than make up for the loss of commonality within 777 fleets. David Anderson, Boeing product development director, says: "It's clear airlines would like a choice. But they also want it at low cost. The GE90 is a terrific engine, and based on how well it's doing in service, we think it will be really a superb match."
Left out of the 777X race, R-R has made the most of its Trent 8104 development, which assumed the role of a technology demonstrator as the thrust requirements climbed beyond its reach. Notional schemes hatched for the 8115, added to the hardware on test for the 8104, have provided options for catering for 777-200/300 thrust growth below the levels foreseen for the "X" models. They have also provided valuable experience for the Trent 500 and 600 efforts - particularly the former, which is on test for the A340-500/600.
For P&W, the decision posed more fundamental questions. For so many years the undisputed leader of the commercial jet engine world, the events of this year have proved to be something of a final wake-up call. Having seen its lead eroded on all fronts by GE, CFM International (with Snecma), and latterly by R-R, the US engine maker had already begun to rally its technological expertise to come up with the PW8000 geared-turbofan initiative. This was originally tailored to meet the CFM56 head-on, and provide it with a sole-source successor to the International Aero Engines (IAE) V2500, in which it was only a major partner. As usual in the engine business, however, events have forced inevitable changes.
New strategies
P&W's strategy depended heavily on the development of a simple, low-cost engine that was to provide the gas-generator platform on which to build the PW8000 family. Using technology derived largely from its US Government-backed research into the Integrated High Performance Turbine Engine Technology programme, the strategy got off to a good start and the PW6000 was selected for the Airbus A318. CFM, which quickly revealed details of its own TECH56 technology upgrade plan for the CFM56 family to reinforce confidence in the future of its best-selling engine, responded with a "cheap and cheerful" solution for the A318 in the form of the CFM56-5B. Air France, which had forced Airbus to offer an alternative engine, selected the CFM56 option in August. The first CFM56-powered A318 will not enter service until 2003, almost a year after the P&W-powered aircraft. The division in the market, although not seriously wounding P&W's plan, was enough to make it reconsider the future direction of the PW8000 initiative.
The GE90 decision, coupled with its loss to R-R the previous year on the A340-500/600, also refocused P&W on the future of its PW2000/4000 series. Such were the omens last summer that, even before it knew it had lost the 777X competition, P&W had re-orientated the PW8000 towards higher-thrust targets. The result, according to P&W, will be an alternative engine to the Trent 500 for use on the big Airbus quads before 2006, the year R-R's agreement with Airbus expires on sole-source supply to the airframer. In the meantime, it hopes to cash in on growing sales of the V2500 on the A320 family, while keeping a close eye on plans for new generation A320 successors and Boeing's New Small Airplane schemes for a 737/757 family replacement - all of which it hopes to meet with PW8000-based solutions.
IAE, meanwhile, has refocused studies of its proposed V2500-A7 version on a refanned development as part of plans to boost thrust by up to 10% over the 33,000lb-thrust -A5 version. The group originally planned to develop more thrust for improved hot and high performance on the A321-200 by introducing a scaled version of the Trent's wide-chord swept fan. IAE recently dropped the plan, however, after market studies showed the costs were too high to justify the costs. It expects to decide on the refanned option by mid-2000.
The continuing search for improvement, plus the unstoppable growth of large fleets of twins servicing the "fragmentation" phenomenon, has also resulted in major upgrades and changes to the second-tier turbofans below the 777 thrust levels. GE, for example, has begun a determined drive to boost the performance and life of its CF6 family by increasing thrust to 72,000lb for the A330-200 with the "A3" version. It is also introducing the "boltless" Rene R88-based turbine to this and the B7/B9F family members, the latter of which powers the 767-400ER. R-R, prompted by performance issues with the RB211-524G/H, is fielding the "hybrid" G/H-T version on 747-400s, which combines the standard engine with the high pressure turbine of the Trent 772. The variant is the first R-R high bypass-ratio engine to benefit from technology trickling backwards through the family line.
The other commercial engine phenomenon gathering pace this year was the growing surge in regional turbofan development. By far the greatest beneficiary to date has been GE, which, with its CF34 family, has practically swept the board by winning virtually all the recent competitions. From a strong base established with Bombardier's Challenger business jet and Regional Jet versions, GE has successfully grown the diminutive engine to effectively twice the original power levels. The omens for the engine were promising following the selection of the 9,200lb-thrust CF34-8C1 version for the CRJ-700.
By the end of this year, GE had embarked on a staggering ramp-up by developing five more versions for regional use. These include the 11,880lb -8D1 for the Fairchild Aerospace 528JET and the 12,500lb thrust -8D3 version for its larger 728JET stablemate. A similarly sized version, the -8E, is in development for Embraer's RJ-170. A larger engine, rated at 15,500lb, the -10D is destined for the 928JET, while its Embraer equivalent, the -10E, is earmarked for the similarly sized ERJ-190.
Pratt & Whitney Canada, which formed the abortive alliance with Snecma on the stalled SPW14 project, had some regional jet success on its own account in the form of the choice of the PW306B for Fairchild Aerospace's 328JET. It followed up on this engine, which was itself a derivative of the PW306A for the Galaxy business jet, with the more powerful PW308B. This powerplant is in development for the Fairchild Aerospace 428JET. R-R Allison's AE3007A turbofan is also in mass production for the growing regional boom, and is in service on the Embraer RJ-135 and RJ-145. Versions are also in development to power Embraer's RJ-140, a hybrid of its T-tail stablemates.
Powering the regionals
Another engine maker with regional ambitions, AlliedSignal, is banking on the four-engined British Aerospace Avro RJ-X for a successful airline debut of its AS977. This advanced new generation turbofan is designed with low costs and low maintenance in mind, rather than dramatic thrust growth, and began test runs in mid-1999. AlliedSignal hopes to use the AS977 to continue the steady progress made with the LF507-powered Avro RJ family, and the surprising (to many) recovery of the BAe 146 family fortunes over recent years. Like P&WC, GE and R-R, AlliedSignal enjoys the benefit of spreading the costs of the venture across the corporate market, and is developing the virtually identical AS907 for Bombardier's Continental business jet. Production of the LF507 continues.
A full-sized airliner, aimed at the regional environment, also entered service this year. The inauguration of Boeing's 717 also marked the airline debut of the BR715 turbofan which had performed flawlessly during the twinjet's certification programme. Manufacturing of the BR700 series, which includes the BR710 for Bombardier's Global Express and the Gulfstream V, will come under Rolls-Royce GmbH by the end of this year, following a stock swop deal with BMW earlier this year. The engine maker, like Boeing, will be hoping for signs of new life in the stagnant 717 orderbook as the new Millennium begins.
The prospects for a happy new year are also brighter for Perm Motors, maker of the Aviadvigatel PS-90A. The company's hopes of continuing engine manufacture rest largely on the success of pioneering commercial lease deals, which, if they proceed, will see production and operation of PS-90A-powered Tupolev Tu-214s. The Perm and Novosibirsk regions of Tatarstan have signed agreements to support the manufacture of aircraft by the Gorbunov KAPO plant in Tatarstan capital Kazan.
One small Western engine manufacturer with big hopes for the next century is Williams International. Having pioneered the development of small turbofans and turbojets for use on cruise missile programmes, Williams is poised to cash in on the proliferation of small, and entry-level business jet programmes with its FJ33 and FJ44 series. Cessna's CitationJet, powered by the FJ44, is due to be joined in growing numbers by FJ44-2 powered CitationJet 2s, Raytheon Premier Is and Swearingen SJ30-2s over the next three years. The FJ33-1 powered Century Aerospace Century Jet 100 and Aerostar Jet projects are expected to add substantially more.
Of greatest potential in the long run, however, is the futuristic FJX-2, which is in development under NASA's General Aviation Propulsion initiative. Using innovative design techniques, many of them still closely guarded secrets, and low-cost mass production methods, Williams believes that the FJX-2 could open the door next century to widespread use of jet-powered aircraft for personal use on an unprecedented scale.
Military power
On the global military front, most of the dramatic progress in the USA appears to have been made during the year by P&W and its varied F119 developments. The initial production version of the 35,000-40,000lb-class turbofan powered the Lockheed Martin/Boeing F-22 Raptor to supercruise speeds of Mach 1.5 without afterburner over Edwards AFB, California, on 21 July, and has proved robust and reliable in tests, says the US Air Force.
The US Department of Defense hopes for equally high standards of performance from four F119 derivatives under development for the Boeing and Lockheed Martin Joint Strike Fighter (JSF) contenders. Two versions of the JSF119-611 are in final development for Lockheed Martin's X-35, the first of which has been shipped to Palmdale, California, for installation in the conventional take-off and landing (CTOL) variant. A second version, which will drive a lift fan via a gearbox and drive shaft, is due to power the short take-off and vertical landing (STOVL) version of the X-35 around the third quarter of next year. Just across Palmdale's runway, Boeing's X-32 contender is expected to have its JSF119-614 engine installed at about the same time as its CTOL competitor. The STOVL version, which depends for power on a direct-lift variant of the engine, is due to fly in mid-2000. As of early this month, the smooth development of both STOVL engines was threatened by lift system hardware and control software related issues.
In Europe, next year also marks a major milestone for Eurojet, the international team developing the EJ200 turbofan for the Eurofighter. Eurofighter was scheduled to complete initial certification testing of the engine by late last month, marking the formal transition from development to production. Pending a successful review, the first production EJ200s are due to be completed by mid-2000 and, by 2001, will roll off the four lines in Germany, Italy, Spain and the UK at the rate of 10 a month. Eurojet also hopes to sign up new business for the EJ200 next year, possibly on the Brazilian-Italian AMX and, at a later date, on the Saab/BAe JAS 39 Gripen.
Source: Flight International
