GUY NORRIS / LOS ANGELES
Boeing's next big project, the 7E7, made a small but crucial advance in March - but is it in step with the market?
On 28 March Boeing quietly filed for both type and production certification of the 7E7 with the European and US regulatory authorities. Compared with formal launch or first flight, this relatively minor paperwork exercise rarely warrants a mention. For the 7E7, however, it could be a different story. Filing for certification takes the 7E7 one crucial step beyond a string of recent failed derivative efforts, and signals something new. It says Boeing seems finally to have shaken off its strategic indecision and speaks volumes about its confidence in the 7E7 market.
As the Paris air show gets under way, however, the big question is whether the market, rather than Boeing, is serious about the 7E7. Although broadcast by Boeing as a "global" jetliner for a new world, the airline response to the 7E7 has been relatively cautious compared with the excitement following the unveiling of the Sonic Cruiser in 2001. Given the sudden demise of the Cruiser, and the state of the market, this is probably not surprising. Added to this, the dwindling sales backlogs of the 757/767 - the two main models to be replaced by the 7E7 - has further fuelled scepticism of Boeing's 3,000-plus market projections. Only recent reports of solid, but still unconfirmed, interest from All Nippon Airways and Japan Airlines have done anything to counter this.
What the world interpreted as uncertainty was, says Boeing, normal product development. In today's transparent marketplace, the news of Sonic Cruiser, and by default the 7E7, emerged much sooner than anyone at Boeing bargained for. Years of unseen gestation turned into a public process that Boeing dislikes - even if it stole some of the limelight from Airbus and the launch of the A380. Toby Bright, executive vice-president sales at Boeing Commercial Airplanes (BCA), says: "We were taking the right steps [with Sonic Cruiser] to check out the market - we're good at that."
Boeing does not deny the damaging fallout from the period. BCA's vice-president of business strategies and marketing Nicole Piaskecki is in the vanguard of efforts to rebuild the company's image, and cites the internet-based "Name the plane" contest with AOL Time Warner as an example of how "we must be more bold, more visible". She adds, however, that in the future BCA will probably "bother people less with all the work we have to do on the alternatives" until a design is more firmly fixed. "We're not just going to stick to a plan because we said we'd do it just to be seen to be consistent - that's stupid," she says.
Market credibility
The 7E7, therefore, is seen as much more than a vital element of Boeing's 21st century family, it also represents a "must win" opportunity to regain market credibility. It is also good for morale. "It's exciting for the whole team to be working on a new project, particularly at a time like this when, if you're not careful, you can be despondent. It's brought the morale of the whole company up," says Bright, who is in the frontline of the sales campaign.
Part of the credibility battle comes by showing that the Sonic Cruiser really did pave the way for the technology of the 7E7 - a point constantly reinforced by BCA president Alan Mulally. "No-one seems to get this. It's the same aircraft, the same market, the same size - we got it right. We didn't waste a dollar and all the technology will go into the new aircraft," he says.
The roots of the 7E7 go back to the reference aircraft developed by product development as a yardstick against which to measure the advances being proposed on the Sonic Cruiser. Advances in overall structures, materials and systems were therefore as relevant to the "Super Efficient" aircraft, as it became known, as they were to the Cruiser. The big differences in configuration, and the main reason for Boeing's image challenge, are related to the change from speed to efficiency - from Mach 0.98 to M0.86.
The pace of evolution remains rapid, and already the 7E7 has undergone several transformations as it moves towards the firming up of the basic requirements outlined initially in the first quarter of this year. This will see more precise definition of the exact mission requirements, passenger capacity options, range, cross section, cruise speed and thrust among others.
Following the firming up of these factors, due in August, the final design concept will be set around one month later. This will dovetail the finalised design and mission requirements with the winning group of systems and design features due to emerge from a three-month intensive competition phase also ending around early August. This decides basic flightdeck philosophy, commonality features, interior flexibility requirements, airport infrastructure issues, common core architecture, system reliability and choice of materials.
The final 7E7 family versions will then form the focus for marketing efforts from late 2003 to late 2004, with firm configuration being frozen at the end of the first quarter of 2005. First flight would then be set for the first half of 2007, with certification and initial deliveries in 2008.
While the shape, size and systems details will certainly change before then, Boeing has never let go of the fundamental requirements driving the 7E7. First and foremost is efficiency which, in these depressed times, has become the linchpin of the entire effort. With Airbus's A330-200 as the datum, Boeing had targeted around a 23% improvement in overall efficiency based on relative fuel used per seat. However, as the 7E7 is expected to develop into a four-aircraft family capable of replacing everything from an Airbus A300 and A310 to a 767-300 and McDonnell Douglas DC-10, this is a moving target.
To get near any of them, the 7E7 will have advanced turbofans with a bypass ratio of between nine and 12, versus five on the 767-300ER. Fan diameter is expected to be between 2.66m (105in) and 2.92m, against 2.36m for the 767, while overall pressure ratio will be raised to around 50:1 as against around 30:1 on the 767.
Engine downselect
Crunch time for the engine makers is expected in the third quarter, when Boeing is expected to downselect to two - or maybe one - supplier. While technical arguments will be crucial, many expect financial muscle to play a part, as it did with General Electric's sole-source win on the 777 long-range models. Although this might be expected to put Pratt & Whitney and Rolls-Royce in a relatively weaker position, both engine makers strongly believe the market will push Boeing towards a more traditional two-horse engine option.
All three engine makers are pursuing similar technology paths towards the stringent 7E7's performance, noise, emissions and efficiency targets. Chief among them is the "more electric" engine that sees more power for aircraft systems and accessories coming from engine-driven electrical generators than the less efficient engine air bleed systems of today. Other features include more advanced turbine hot section materials and cooling, low-emissions combustors, next generation low-speed, high-flow fan designs, improved three-dimensional aerodynamics in the low-pressure compressor and faster, easier maintenance features such as "quick-change" line replaceable units. Propulsion is expected to contribute around 17% of the overall efficiency improvement.
Advanced structures will also play a vital part in reducing the overall weight and improving resistance to fatigue and corrosion. The materials, which will also include some advanced aluminium alloys, provide a potential pathway to the incorporation of new structural health monitoring technology which, in turn, is expected to reduce the number of scheduled interruptions.
The structures initiative is grounded in the 777, which was more than 1,180kg (2,600lb) lighter due to the extensive use of composites. Some 777 repair technologies have also helped pave the way for the expected use of several non-metallic materials, ranging from graphite-epoxy and honeycomb to ti-graphite, a sandwich of toughened graphite-epoxy and advanced aluminium similar to the Glare laminate used on the Airbus A380.
Systems advances will "buy their way on", insists 7E7 programme vice-president Mike Bair, whose team is considering a wide range of high-technology options. These range from natural evolution developments, such as integrated modular avionics and common core systems architecture, to more radical changes, including a hybrid electric/hydraulic fly-by-wire flight control system, and an aircraft energy management system. The cabin, like the aircraft itself, will also be "e-enabled" to allow passengers to connect to e-mails, the internet and other communication and entertainment modes.
The 7E7 is expected to be baselined with an onboard inert gas generation system (OBIGGS) to reduce the weight and maintenance burden of oxygen cylinders. It is also expected to feature a high-voltage, variable frequency power generation system. The environmental control system will probably be electrical, rather than use bleed air, while the auxiliary power unit will also be "no-bleed", and provide AC power only.
"Ovalised" cross-section
A fundamental design feature decided on by March was the selection of an "ovalised" cross-section that provides the same LD-3 underfloor container compatibility as for the Airbus A330/A340, but which increases the cabin width at shoulder level. The section resembles the ovoid of the 767, but without the double-bubble intersection at the main cabin floor level. This retains, therefore, the structural and aerodynamic efficiency of the circular 777 cross-section, while avoiding the assembly complications of the 767.
Measured at the 1.27m (4.2ft) height level, the 7E7 cabin provides up to 730mm more width than the 767 and 340mm more than the A330. Although emulating the cabin comfort levels of its larger sibling, the 7E7 is also 450mm smaller in cabin width than the 777. Height from floor to centre overhead bin, for example, is exactly the same on both aircraft at around 1.9m.
The configuration provides ample space for wider seats and aisles than does either the 767 or A330, and in the first serious iteration - dubbed the 7E7-300X/400X, provided space for up to 241 passengers in a three-class arrangement. On the shorter - 300X model, 202 people could be seated in Boeing's arrangement, which included 12 in first, 36 in business (48in/1.22m pitch) and 154 in economy. The -400X, by comparison, could seat 12 passengers in first, 44 in business and 185 in economy under the same layout arrangement.
The -300X/400X names disappeared by March and for a short time were superseded by 7E7 and 7E7STR (stretch). These subsequently morphed into two main subsets, the baseline and stretch 7E7SR (short range) and the baseline and stretch 7E7LR (long range). These new groupings emphasised the revised marketing strategy of the 7E7 that reflected the increasingly divergent areas of airline interest. Of the almost 40 airlines helping advise Boeing, some wanted long-range, point-to-point capability between 13,800km (7,460nm) and 14,800km, while others wanted a 21st century short- to mid-range (5,550-7,400km) replacement in the 250- to 350-seat range.
To cater for all, without losing focus on the "keep it simple" strategy, Boeing is tailoring the 7E7 into four main offerings: a baseline LR aircraft seating around 200-220 (in three classes), with a 14,430-14,800km range; a stretched LR seating up to 260 with a range of around 13,320-13,690km; a baseline SR seating between 320 and 340 (in two classes), with a 5,550-6,300km range; and a stretched SR seating between 280 and 310 with a range of around 6,500-7,400km. The baseline aircraft, both SR and LR, is expected to be around 58m long, while the stretch is lengthened by almost 7m to around 65m.
Keeping it simple while satisfying such divergent requirements with the same design poses unique challenges requiring unusual solutions. One such possibility is an optional wing "tip treatment" which will allow shorter-range operators to use smaller gates. Although Bair says airlines accept aircraft with "latent capability" for fleet flexibility and higher residual values, he says meeting the wingspan change is the "biggest complication". The LR models are presently sized with a span of around 57.3m, while the SR aircraft is expected to have a span of roughly 50m.
The external configuration also changed as Boeing sought to "jazz up" the overall appearance of the 7E7, differentiating it from the 777 and giving it more of a 21st century look. The changes, which include a reprofiled nose section, faired vertical tail and blended tips on both the wing and horizontal tail, are essentially cosmetic and will only be adopted if they have a neutral or positive aerodynamic impact, says Boeing.
Against the background of launching the 7E7, Boeing is wrestling with forming new industrial partnerships to shoulder more risk than any previous Seattle-based design. Through consulting firm McCallum Sweeney, it also scouring the USA for a final assembly site, with final bids due by the end of the Paris show. This appears to be Boeing's signal that in 2004 the 7E7 will be launched as a completely new aircraft, to be built in an entirely new way by an entirely new company.
Source: Flight International
