FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1987
1987 - 0858.PDF
Left Boeing's 767-300ER looks like a success story. Right The A310-300 has long range, but not as long as that of the 767. Airbus will probably make a long-range Etops A330 Maker Airbus Boeing Type A310-300 A340-200 A340-300 767-200ER 767-300ER Douglas MD-1 1 MD-11ER MD-1 1 Combi MD11F Notes: Range 5,250 8,150 7,300 6,700 7,670 7,300 7,700 6,000 5,000 Passengers 220 262 295 211 258 321 277 Variable N/A Range: nautical miles, ISA, still air, no reserves Passengers: standard multi-class seating Airbus Industrie's A340 has had a turbulent run-up towards its launch, and the seas are still stormy. Paris is expected to bring the announcement which will define the A340's production future, the only factor delaying a launch decision shortly before the Air Show being the German Government's delay over its consideration of how to handle its Airbus Industrie financial investment decisions. Germany had decided in principle to back the A330/A340 programme, but the deci sion was a more complex one bound up with Deutsche Airbus' considerable current deficit, and what to do about the deficit and the A340 investment as a whole. Just before Christmas, at a time when the MD-11 was visibly just about to be launched with a creditable number of launch "commitments" from solid airlines and the A340 was in danger of sinking from view, Toulouse stole a march on Long Beach: Airbus announced the SuperFan-powered A340, and a larger version (the -300) which competed almost directly with the MD-11. The standard version, the longer-range A340-200, remained on offer also. The SuperFan, a very-high-bypass engine with its variable- pitch fan driven by an International Aero Engines V.2500 core via a reduction gear box, was to offer a 15 per cent improve ment in specific fuel consumption. By early April it had become clear that IAE would not be able to deliver the SuperFan in anywhere near the time frame required, but by that time the A340 had benefited from the equivalent of a marketing coup. With SuperFan's demise, Airbus had then to come up with a believ able alternative powerplant and believable stories about how it had been taken for a ride by IAE. In fact Airbus and IAE had never signed any agreement over the revo lutionary powerplant, so it looked as if the only people who had been taken for a ride were the airlines which had put in A340 orders, and they had to be convinced that they had not been. Airbus seems to be coping with this situation now, though there have been rumblings of discontent from customers as faithful as A340 commissioner and launch-buyer Lufthansa. Now the engines are to be Snecma/General Electric CFM56-5Cls, the ultimate (or surely near-ultimate) development of the highly succesful and highly reliable CFM series of turbofans. Since this 31,0001b-thrust engine cannot produce the same specific fuel consump tion as the SuperFan, Airbus has intro duced some design changes to the original A340, rather than let the promised range reduce. These include longer wings, and the introduction of 3m-high winglets at the tips; wing aspect ratio is increased from 9-1 to 9-3; and fuel capacity is increased by 6-7 tonnes. "We were prepared for the loss of the SuperFan", senior engineering vice- president Bernard Ziegler tells Flight, "the CFM engine was always developed in parallel... we were on our way to issue the specification for the wing fins even with the SuperFan." Airbus has not frozen the final A340 design yet, and does not expect to do so for some time, though it will freeze the guaranteed minimum performance specification by September. The nature of the "specification freeze" is that it forms a contract with ordering airlines, and any change thereafter has to be negotiated. Unofficial Airbus estimates for A340 sales have been put in the region of 270. Since no manufacturer could expect to profit from such a small run, the whole commercial argument depends upon the A340's commonality with the larger short/medium-range A330. They will share the same basic hull, the same cock pit, the same wings. So how can they both be efficient for their specialist tasks? The answers hinge on the wing design, explains Ziegler. The basic shape and structure may be the same, but slat and flap differences, plus the aerodynamic flexibility conferred by computer- controlled variable camber, makes the wing not only efficient for each type, he says, but gives maximum aerodynamic efficiency throughout each individual flight. This capability, provided by specially designed flap systems, gives most advantage to the longer-range aircraft because its weight changes so considerably during its routes. There will be significant differences between the A330 and A340 wing in the pylon/wing areas because the engine pylons will be different in shape as well as number; but the biggest differences, Ziegler says, will be in the slats and flaps: "There will be a lot of local modifications where the junctions are with the engine flow". The design is intended to allow the differences to be "bolt-on" to an identical basic wing so that the structure can be started on the production line without necessarily "knowing" which of the two types it will eventually lift. Ziegler explains that variable camber is expected to be unused on some A330 legs: "We expect the A330 to be used for very short range as well as 5,000 n.m. or so—London-Paris for example. The flap on such a leg would probably be in a fixed position [during the cruise sector]. It would be in a very different position for London-Los Angeles." There is no doubt that, in the long run, Airbus intends to develop the A330's capabilities well beyond the current advertised short/medium-range market. Even the first of them will have Etops equipment as standard, Ziegler says. But in the longer term Airbus evidently sees a market which Boeing is already attacking successfully with its Etops-equipped 767-200ER and -300ER, and the Euro peans intend to attack it with longer- range versions of the A330. Where wing size, and therefore fuel capacity, has been the ultimate long-range strength of the 767 and the weakness of the A310, the A330's limitation will be engine power. The first A330s will need at least 64,0001b thrust which, Ziegler says, General Electric is contracted to produce, Pratt & Whitney has given a commitment to produce, and Rolls-Royce is thinking about producing with its proposed RB.211-700. Without specifically mentioning long range, Ziegler continues to describe the A330's engine needs: as it develops, he says, "we need at least to go to 68,0001b and probably to 70,0001b". To carry a lot of fuel you need a lot of power. So Boeing has the long-range market covered with its 747 and the Etops 767ER; McDonnell Douglas has a range of MD- 11s; and Airbus fields the A340, the Etops A310-300, and obviously has in mind to stretch the A330's range if Etops is the way the world wants to go. It will be an interesting fight which will change the nature of long-range flying by increasing hugely the number of non-stops and second-city connections. S3 96 FLIGHT INTERNATIONAL, 13 June 1987
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
