Julian Moxon/PARIS Max Kingsley-Jones/LONDON
The long-awaited commercial launch of the A3XX on 23 June was the culmination of a huge effort by Airbus Industrie to gather sufficient interest in an aircraft that sceptics thought would never see the light of day.
Just 30 years after the Airbus consortium was formed, the European aerospace industry has positioned itself to offer a complete range of airliners spanning 100-550 seats. Without the A3XX, Airbus was always going to be threatened by the dominance of Boeing in the ultra-large aircraft sector and its ability to fund other programmes from it. Airbus makes no secret of the fact that while the A3XX will account for 10% of the aircraft it builds, the programme will contribute 25% of the profits of the company that will now be formed on 1 January, 2001.
With letters of interest from nine customers for over 60 aircraft before the commercial go-ahead, the A3XX is off to a good start. This follows years of extremely careful preparation by Airbus and a group of 20 airlines to ensure that the A3XX is the right aircraft for the market.
Airbus has used the idea of letters of interest - amounting to a kind of "pre-commercial launch" - for the first time and this was an essential prerequisite to launching a programme that is expected to exceed $12 billion in development costs. The letters are not contractual commitments, but are seen as a kind of "gentleman's agreement" between Airbus and the airlines, giving the latter the chance to sign up as launch customers and benefit from a healthy discount on the list price.
Airbus quotes the list price for the baseline A3XX-100 at around $220 million, and discounts in the region of 30% are believed to have been offered.
With the customer pledges collected, Airbus was able to convince its board that the project had sufficient airline backing to justify going to the market with a fully specified and priced aircraft. "Both sides had to put their neck on the line," says Airbus commercial director John Leahy, a tireless advocate of the A3XX. "Never in Airbus' experience has there been so much airline interest at this stage of a programme."
The difficult period of selling the A3XX concept to airlines and risk-sharing partners has been replaced by growing confidence inside and outside the consortium that it is ready to meet Boeing head-on in a market where the Seattle giant has enjoyed a three-decade monopoly.
The uncomfortable "chicken and egg" situation which saw airlines reluctant to sign for a programme that lacked sufficient industrial backing is over. Now it seems possible that by the end of the year there may be as many as 50 firm orders - a figure that was but a dream when the year began.
The A3XX family includes three fuselage sizes and cargo versions, although just two - the baseline 555-seat -100 and -100F freighter - are clearly defined. Airbus plans to develop quickly an increased-weight version of the A3XX-100, incorporating a strengthened structure, from which the -100F will evolve, as well as the -100C combi and ultra-long-range -100R passenger model. The freighter will have large cargo doors on both decks and a 150t payload capability. A stretched 656-seat A3XX-200 is planned, as well as a 480-seat A3XX-50 "shrink". Specialised short-range derivatives of both the -100 and -200 are also on the drawing board.
The A3XXtimetable envisages full industrial go-ahead at the end of this year, with the first -100 flying in mid-2004 and entering service in late 2005. The cargo version follows two years later. The timetable for other proposed variants is less defined, and will presumably depend on where the strongest market interest lies.
Airbus' current market forecast says there is a requirement for 1,200 passenger aircraft and 300 freighters in the A3XX category over the next 20 years. "We expect to capture at least half of that," says Leahy.
The consortium plans to raise 40% of the A3XX development funding from risk-share companies which will fund their own work. The remainder will come from the Airbus shareholders - 30% from their governments in the form of repayable loans and 30% from the shareholders' own resources.
Commitments have been received from nine outside companies for risk-sharing partnerships on the programme. They include:
• AIDC (Taiwan)
• Belairbus (Belgium)
• Eurocopter (France/Germany)
• Hurel Dubois (France - up to 2%)
• Finavitec (Finland)
• GKN Westland Aerospace (UK)
• Latecoere (France)
• Saab (Sweden up to 5%)
• Stork Aerospace (Netherlands)
As with all Airbuses, CASA of Spain (now part of EADS) is responsible for the tailplane, BAE Systems the wings, Aerospatiale Matra (or EADS)the cockpit and centre fuselage, and DaimlerChrysler Aerospace (EADS)the forward and aft fuselage sections and fin. Ten additional manufacturers have signed up to produce other components as risk-sharing partners.
In terms of technology, the A3XXholds no major surprises. Pilots will find themselves in a cockpit developed from the current fly-by-wire family, and will benefit from similar procedural and handling characteristics, albeit with a number of changes reflecting advances in technology, both on and off the aircraft.
"The A3XX retains all of the family concepts which allow cross crew qualification and mixed fleet flying," says Philippe Jarry, vice-president of market development for Airbus Industrie's large aircraft division.
Although Airbus has chosen a relatively low-risk technology path for the A3XX - compared, for example, with the leap forward of its first fly-by-wire aircraft, the A320 - its flagship product will sport a number of new technologies as well as refinements of existing ones.
Operating cost target
The overriding target was to meet airline demand for direct operating costs (DOC)per seat at least 15%-20% lower than those of the Boeing 747-400, while keeping programme risk to a minimum. At present, Airbus claims a 16% reduction for the baseline 555-seat A3XX-100, achieving about 10% of this by the simple expedient of building a bigger aircraft. It claims that the A3XX's fuel burn per seat will be 13% lower than the 747-400.
The remaining 6% of DOC savings are achieved entirely through technology advances, both in the engines - either Rolls-Royce Trent 900s or Pratt &Whitney/General Electric Engine Alliance GP7200s - and in the airframe, through aerodynamics, weight and systems design. "New technology is mandatory if we are to reach the DOC reduction we're looking for," says Robert Lafontaine, vice-president of engineering and product development for the large aircraft division.
The aerodynamic advances incorporated into the A3XX have been confirmed in more than 50 wind tunnel tests across Europe and have led to the recently added A320-like wingtip fences to reduce lift-induced drag.
The A3XX will be less naturally stable than its predecessors, the fly-by-wire system permitting control to be maintained with the centre of gravity moved 6% further aft compared with the A340. Because this is closer to the aerodynamic centre of lift, less downforce is needed to maintain stability and the size of the tailplane can be reduced from 240m² (2,580ft²) to 200m², with a corresponding reduction in drag. The rearward centre of gravity position was confirmed in a series of flight tests aboard a modified A340 in June last year.
The fin surface area - which will be about the same as that of the A320 wing - is also kept to a minimum by arranging the aerodynamic geometry so that dutch roll, and not engine-out considerations, is the sizing factor.
There will be no reversion to a mechanical flight control system on the A3XX, the fly-by-wire concept now being considered mature enough to cater for all failure modes. The A3XX has a "smart direct" law, in which the backup electrical flight control system drives the rudder, elevator and tailplane trim.
Unlike on previous Airbus aircraft, this is a fly-by-wire system, but it uses a separate computer and sensors.
Aerodynamics have also benefited from the use of A340-style floor beams for the two-deck A3XX. These differ from previous Airbus practice in being integral with the fuselage cross-beams that support them, enabling the thickness of the overall structure to be reduced by about 50mm (2in), reducing the height of the ovoid fuselage by 100mm, saving 300kg (660lb) and reducing profile drag.
A major effort has also been made to minimise energy requirements and the resulting demand on engines, and to reduce the weight of aircraft systems - particularly important in an aircraft the size of the A3XX, in which hydraulic tubing and the liquid it carries is disproportionately heavy. A 345 bar (5,000lb/in2) hydraulic system has been approved, and this will reduce the size of the actuators needed for the huge A3XX control surfaces, reducing weight by about 1,200kg.
"We want to ensure the A3XX has a very robust architecture to cater for particular risks such as engine burst, auxiliary power unit burst and structural damage," says Lafontaine. This has driven a design using four independent and dissimilar power systems to actuate the moving surfaces, each of which provides fully independent control.
Two of the systems are hydraulic, one driven from engines one and two, the other from three and four. A third uses electro-hydrostatic actuators (EHA) and the fourth electrical back-up hydraulic actuators (EBHA) supplied by electrical systems one and two. This is the first time EHAs will have been used on a civil aircraft, the aim being to eliminate the need for hydraulic tubing, instead providing the hydraulic power by an electric pump mounted on the unit itself.
It has been decided to use a new aluminium alloy/glassfibre reinforced plastic composite material, Glare, for the entire top half of the fuselage. Developed by Delft University and Fokker in the Netherlands over the past 15 years, Glare comprises thin layers of aluminium alloy sandwiched between layers of glass fibre oriented in specific directions to give the resulting composite exceptionally good damage tolerance, fatigue resistance and fire resistance, as well as yielding a weight saving of up to 1.5t.
Other advances in materials include a carbonfibre centre wing box, all-welded lower fuselage shells and use of advanced alloys (already used for the A340-500/600) for the inner wing sections. A decision has yet to be taken on constructing the outer wing sections from carbonfibre. A new design concept for the nose's structural configuration will save a further 800kg. As with earlier Airbuses, the entire tailplane and fin will be constructed from carbonfibre.
One of the main operational concerns with an aircraft the size of the A3XX is wake vortex, which has become ever more important as traffic density increases and aircraft are squeezed closer together.
Current separation rules are based entirely on aircraft weight - a situation that Airbus wants to change because, it says, vortex strength also depends on wingspan and aerodynamic properties. It cites US Federal Aviation Administration/NASA studies which have shown that vortices from four-engined aircraft decay faster than those from twins, and says that the A3XX wing, which will have a similar architecture to that of the A340, already has low vortex-inducing characteristics.
Airbus has already undertaken a lot of windtunnel research on the A3XXand initial theoretical estimates show it will have 10-15% greater vortex strength than the Boeing 747, despite its 30-40% greater weight. This results from careful aerodynamic design in areas such as engine position and spacing, underbelly fairing, main undercarriage, flap type, flap setting, aileron philosophy and interaction of engine exhaust and flap end vortex. The tailplane, with its reduced downward loading, will also affect vortex less, says Airbus.
The aim is to convince the certification authorities that the A3XXneeds no greater separation than the 747. "We know that today's rules are out of date because it has been shown that some smaller aircraft have far worse vortex characteristics than large ones," says Lafontaine.
Airbus is also studying ways of minimising aerodynamic noise from the A3XX, and is confident that it will be quieter than the 747-400.
If the full-sized A3XX cabin mock-up at Airbus' Toulouse headquarters is anything to go by, passengers boarding the real aircraft for the first time will certainly be aware of a huge increase in the amount of space devoted to them.
"The A3XX will provide a totally new flying experience," says Jarry. On entering the aircraft, passengers will see a wide central staircase leading to the full-length upper deck, which Airbus likens to a "second widebodied aircraft flying on top of the first". This reflects one of the market drivers that has led to the twin-deck design - an airline requirement for a single aircraft big enough to replace the two 747 flights now required on high-density routes such as London-Singapore that often take off within minutes of each other. Such inefficiency results from the fact that travellers will not tolerate unacceptable departure and arrival times. So extra capacity has to be found - and the A3XX is the answer, says Airbus.
In high-density configuration, the stretched A3XX-200 will be able to carry 1,000 passengers , which raises the question of exit capacity in the event of an emergency. Airbus says that with nine doors on each side and new upper deck escape slides under development (the supplier is due to be chosen within weeks), "we can meet the 1,000-passenger exit criteria".
Although Airbus has assumed that only main deck boarding will be available when A3XX operations begin in five years' time, the aircraft is designed for simultaneous boarding on both decks once airport infrastructure has been developed to allow it.
Compared to the 747, the A3XX has a claimed 43% more space and 35% more seating capacity, which will allow for wider seats than those flying today - even in economy class. The A3XX's oval fuselage section means that the 5.79m-wide upper deck has the same two-four-two twin-aisle seating layout as that of a current Airbus widebody, and will be able to accommodate about 200 passengers. This compares with the 4.06m width of the Boeing 747's single-aisle upper deck.
Airline input led to the development of a thinner skin structure, which gave an extra 35mm width. Airbus also lowered the cabin floor to provide an extra 15mm in height. The 6.42m wide lower deck will provide 11-across seating in a 3-5-3-layout, compared to the 747's 6.12m.
Each deck will be fully independent in terms of galleys and services, and airlines will be able to take advantage of a flexibility they have never had before. "They are only now becoming aware of that," says Jarry.
Airline feedback has been central to the development of the A3XX and has resulted in many design changes. The main deck cargo door, installed behind the wing trailing edge, has been repositioned five frames further aft to improve accessibility for cargo loaders. The forward cargo hold has been extended enough to accommodate two extra LD3 containers.
Both improvements reflect the attention given to the aircraft's cargo variant, which is attracting considerable interest from carriers and, for the first time, is being launched industrially at the same time as the passenger version. FedEx and Cargolux are likely to be among the first cargo carriers to sign up to the programme and would, according to some sources, take the A3XX tomorrow if it were available. This is not just because of its economics and size, but because the e-commerce market is about to explode as ordering by internet takes hold.
Leahy is in little doubt about the A3XX's future. "I am convinced this aircraft will write the next chapter of aviation history," he says.
The Airbus system has had to be flexible - not only to the demands of the market but also to those of the four members of its consortium. This has meant that there have always been internal struggles over, for example, the locations for final assembly of the range of single- and twin-aisle aircraft that it produces.
Never has this been more so than in the case of the A3XX, the commercial launch of which was delayed while the final details of the production workshare and, in particular, of final assembly, were hammered out.
The choice, initially comprising five sites, quickly boiled down to two - Toulouse, where Airbus has its roots, and Hamburg, which has become the "centre of excellence" for single-aisle Airbuses and which put a premium on winning the competition, not only for the obvious prestige it would bring, but for the jobs it would create.
The argument raged long and hard, and, according to Airbus, was always fought with production efficiency as the main driver. This was certainly the case in the early days of the decision-making process but became more and more centred on the political issues as time wore on and no agreement was reached.
The various scenarios for putting the A3XX's vast airframe together looked at the viability (or not) of assembling it either where water transport could be used to bring the huge sections to the factory - favouring Hamburg - or at an inland site - Toulouse - which had all of Airbus' widebody final assembly experience at hand. Ideas put forward during the selection process included carrying the wings atop an A340 from the UK, carrying fuselage half-sections by Beluga, and even using German airship company Cargolifter to carry pieces around Europe.
As pressure for a commercial launch mounted, a last-minute compromise was thrashed out, giving Toulouse the A3XX final assembly prize, and Hamburg the job of cabin finishing. Green A3XXs rolling off the line at Toulouse at the planned maximum rate of four a month will be flown to Hamburg for finishing.
In a final masterpiece of compromise, those that are intended for long-distance customers will be flown back to Toulouse for delivery, while those for near and medium-range destinations will fly from Hamburg. The official reason is that environmental considerations would have prevented the Hamburg runway being lengthened to accommodate the A3XXat its maximum take-off weight. Unofficially, industry sources admit that all of the aircraft could have flown from Toulouse.
In settling for the French option, Airbus was faced with two choices: either fly sections to the airfield by Beluga - which meant they had to be small enough to fit inside - or transport full-sized fuselage sections by sea from Germany to Bordeaux and take them the rest of the way by road. The latter solution was chosen, which means Airbus will buy at least two ships adapted for the task and several trucks capable of carrying the huge fuselage sections several hundred kilometres to Toulouse.
So Airbus is ready to take its next, bold step. If the air of confidence eminating from Toulouse is anything to go by, the consortium is relishing the prospect of taking its biggest gamble, and waits with interest to see how its competitor Boeing responds.
A3XX EXPRESSIONS OF INTEREST
International Lease Finance
Note: * 10 + 6 options. ** Three more undisclosed carriers have expressed interest.
Source: Flight International