Decision imminent on final design of 787 shell

Paris Air Show » 2005
December 12, 2006, 7:22 AM

Say what you will about Boeing’s political and boardroom troubles over the past few years, the company’s technical proficiency doesn’t appear to have diminished. Just ask 787 program manager Mike Bair, whose engineering team continues to meet virtually every scheduling milestone set when the company launched the Dreamliner project a little more than a year ago.

“We’re essentially right where we expected to be,” Bair told Aviation International News. “We’re done with all the major trades and we’ve locked down what the airplane’s going to do and what it’s going to be, and now all that gets handed off to whatever parties are going to do detailed design.”

The company unveiled the final shape of the exterior fuselage in April, after spending more than 100,000 hours calculating fluid dynamics on supercomputers–one of the hallmarks of the program, according to Bair. “Our codes have really matured since we did the 777,” he said. “That has allowed us to do a lot of fine tuning on the aerodynamics without having to take all that stuff into the wind tunnel every time we change something.”

One of the few details left to settle involved the airplane’s revolutionary electrical system; by last month the team hadn’t yet decided on the most efficient way to package all the wiring and devices in the airplane’s electrical equipment bay, where most of the airplane’s electronics racks reside. Although basically done with exterior design, engineers also hadn’t yet decided on a few minor structural details, such as the exact size and location of the wing-to-body faring and flap hinge farings. Boeing plans to settle on the final configuration soon after the Paris Air Show, in what Bair described as a rolling schedule expected to run into next month.

Meanwhile, the company has finished building three full-size fuselage barrels, meant to test both composite production techniques and to develop a database for certification analysis. It expects to complete the first nose section by either the end of this month or early in July.

Although lighter than aluminum, the lower weight of the composite airframe contributes relatively little to the 20-percent fuel burn savings Boeing projects for the 787. Rather, operators will likely see more benefit from lower maintenance bills, said Bair, notwithstanding all the early talk about the need for new repair techniques to fix ramp rash. Normally, a metal airframe must undergo heavy overhaul D checks every six to eight years. The 787 can go 12 years between major inspections because composites don’t corrode.

More maintenance cost benefit will come from simpler systems, such as a pair of electrical generators on each engine, used in place of a traditional bleed-air system for cabin pressurization. The 787 will also be the first airplane to use electric brakes. With the help of computer software that allows the pilot to control the amount of pressure placed on the brakes, the system “significantly” reduces wear to tires and wheels as well.

Despite popular opinion, the switch from liquid cooling for much of the electronics and galley chilling should actually help reduce maintenance, according to Bair. “You cool electronics today, but you do it by blowing air around,” he said. “So you have to have ductwork, which obviously is bigger and heavier than pipes for liquid cooling. And also the valves and claptrap you need to control the cooling air is actually more complicated and less reliable than that used for liquid cooling.”

As usual, engine advances will account for the largest cost benefit–roughly 8 percent of the promised 20 percent fuel-burn advantage over the 777-300ER. On that score, the two engine companies chosen to build the powerplants for the 200- to 300-seat jets–General Electric and Rolls-Royce–so far seem to have met expectations.

“In all of the past development programs that I’ve been on, engines have been a worry item,” said Bair. “On this, both the Rolls and the GE programs are going really well. In fact, there hasn’t been a huge amount of conversation from my leadership team about the progress we’re making with the engine guys.”

Powered by either the GE GenX or Rolls-Royce Trent 1000, the 787 will use a common engine core designed for the long-range 787-8 and de-rated for the short-range 787-3. From the start not interested in offering engines from all three major engine builders, Boeing and the financial community probably would have liked to limit the powerplant award to a single manufacturer. But it quickly became apparent Boeing would have to offer at least two after potential customers made clear they wanted engine suppliers to compete for their business.

Of course, if a Rolls-Royce-powered airplane enters the resale market and the only interested buyers fly GE-powered equipment, the cost of replacing the engines will inevitably lower its value. In an effort to comfort lenders, Boeing will offer a so-called swap option that will allow an operator to change an engine in 24 hours. “There’s a lot of stuff in terms of standardization that’s being driven by the banking community,” said Bair. “They have now publicly stated that if we accomplish what we have laid out in front of them, the airplane is going to have higher loan-to-value than any other airplane, and they can see anywhere from 50 to 100 basis points reduction in the borrowing rate.”

Goodrich Aerospace has designed two different 787 nacelles, both of which will fit on the same attach point, allowing operators to unbolt and re-hang either engine without the need for structural changes. In fact, all the major suppliers have designed their own components, freeing Boeing to focus almost solely on integration–another departure from tradition for the Chicago-based manufacturer.

A month before the start of the show some of the biggest suppliers–Kawasaki, Fuji, Mitsubishi, Alenia and Vought–had yet to sign firm contracts with Boeing. Earlier this year reports circulated that the hold-up may have stemmed at least partly from cost pressure from Boeing and delays in government loan guarantees. Bair flatly rejected that notion, however, and insisted all the parties would sign by early this month. “Nobody’s in a big rush; we’re being very, very methodical,” said Bair. “I think when we sign these they’ll be the largest commercial aviation supply agreements in history. So it’s to everybody’s advantage to make sure we get them right.”

A month before the start of this week’s show the 787 had accumulated “commitments” for 255 airplanes from 20 customers. Bair said the company has received request for proposals for another 411 airplanes from 25 more prospects, and expected new orders before the show. “Probably one of the biggest issues we have right now is delivery positions,” said Bair. “We’re essentially sold out in ’08 and ’09 and if we’re not sold out in 2010 right now it will happen in the next couple of weeks.”

Launch customer ANA expects to take its first 787-8 in 2008, and immediately press the airplane into service on a route between New York and Tokyo. U.S. launch customer Northwest Airlines plans to inaugurate its first 787 service on the same route. At first glance the decision to start service between such huge markets seems counterintuitive, given that Boeing markets the 787 as a vehicle to serve thinner, more varied markets. In fact, Boeing has identified more than 400 routes not flown today that the 787 could potentially serve. Even so, said Bair, today’s fierce competitive environment also demands more flexibility on dense O&D routes.

“If you look at those routes, there’s a lot of competition…probably seven or eight airlines flying 15 frequencies a day with relatively large airplanes, and all of them having a very hard time making money,” said Bair. “The minute one of these carriers drops in a 787, that mission is instantly profitable."

FILED UNDER: 
Share this...

Please Register

In order to leave comments you will now need to be a registered user. This change in policy is to protect our site from an increased number of spam comments. Additionally, in the near future you will be able to better manage your AIN subscriptions via this registration system. If you already have an account, click here to log in. Otherwise, click here to register.

 
X