Clean-Sheet – Boeing’s all-new jet: Configuration and Materials

Boeing 737-800 VQ-BOS BBJ2

This is the first in a three part series on the development of Boeing’s all-new jetliner. Part one examines market evaluations and the configuration and materials selection process. Tuesday’s Part Two will explore the aircraft’s systems, propulsion and performance and Wednesday’s Part Three will look at the future production system and business model of the new jet.

Until now, few answers about Boeing’s next aircraft have been available and while the majority of its attributes have yet to be determined – including its launch – the all-new jet will be one aircraft, not two, and whose configuration will match the familiar tube and wing that defines commercial air transport today.

In recent months, Boeing has been quietly polling the worlds most influential airlines, offering them a veritable “grab-bag” of technologies, say industry officials, with the goal of identifying their future needs for an all new jet that is intended to first see revenue service in 2019 or 2020.

The task Boeing is now preparing itself to undertake – the development of the airframer’s next generation narrowbody – is now in the early planning phases. By the Paris Air Show in June, Boeing will announce the direction its intends to advance, deciding between an all-new design or a re-engined 737.

If Boeing can replicate the design resiliency of the original 1967 737-100 and -200, then “getting it right” now means laying the groundwork for an aircraft that will evolve well into the latter half of the 21st century. Boeing has succeeded in evolving the 737, making incremental improvements to the aircraft over time, without having to make the multi-billion dollar investment to fully replace the narrowbody, all while maintaining its existing industrial footprint for ever increasing production.

Despite that longevity, what the market doesn’t appear to want, says Mike Bair, vice president of Advanced 737 Product Development, is a re-engined 737: “I kind of characterize it as more underwhelmed than overwhelmed and almost all of them want to know what more we can do with a new airplane, so that’s kind of where our focus is right now.”

Though standing in the path of the all-new aircraft are significant unanswered questions about the commercial success of the 787 and what technology from its long-range twin can be used in a smaller platform. In charge of this effort is Bair, who first must answer the question from which all other answers will be yielded: What does the market want?
Boeing’s focus, says Bair, who has been in this role since January 2010, is to “figure out the art of the possible” for the company’s next all-new jetliner, which he says is less of a 737 replacement and more of an aircraft meant to fill the marketplace spot below the 210 to 250-seat 787-8, suggesting an aircraft centered around a segment slightly larger than today’s narrowbody.

“I try not to say 737 replacement, because what we’re trying to understand is what does the world need in 2030? Because if the airplane goes into service in the back half of this decade it’s going to be in its prime, plus or minus. So we’ve got to look that far out and try and makes some calls about what the world’s going to want out there.”

Six-Abreast or Seven-Abreast?

Boeing’s first industry trial balloon, confirms airline and industry officials, contains two notional cross sections: a six-abreast single aisle and a seven-abreast twin-aisle with a container-sized lower cargo hold sized smaller than the 767.

“There’s a wide open area in terms of what could be the cross section and that’s clearly a big conversation we are having internally and also with the airlines,” say Bair without going into specifics.

However, despite two cross sections and two potential aircraft families, Bair quickly rules out two aircraft families making it off the drawing board, eliminating a repeat of the concurrent development of the all-new 757 and 767 in the early 1980s.

“We won’t do two cross sections, it will be one, but we don’t know yet what that will be and we’re showing a lot of options to airlines and at some point we’re going to have to make the call,” he says.

“Obviously the wider the cross section, it’s not free, you lose efficiency for making the airplane wider and we need to understand how much are the airlines willing to spend, basically, on a wider airplane.”

One part of that determination is a flying focus group that is taking place on the roughly three dozen 737′s delivered with the Boeing Sky Interior. The new design allows passengers to load and unload the overhead bins without having to step into the aisle, says Bair, who adds Boeing is “watching very carefully” if this ergonomic change can improve aircraft turn time without the need for adding a wider or even a second aisle and a seventh seat.

A Radical Departure?

As it works to develop the configuration of the new aircraft, Bair says his team has ruled out radical configurations such as a blended wing body for two “pragmatic problems”. The first, has to do with the window arrangement, or lack thereof.

“A lot of people just say ‘give them TV screens and stuff’,” he says, “But one of the things we clearly found during our ’87′ journey is that people really like to look out the window.” The second, he adds, is the extra-wide cross sections that have passengers “a long way away from the center of the airplane and when the airplane does a roll manuever you better have your seatbelt on.”

Additionally, an unducted fan engine, while providing significant fuel burn improvement, would require a 14 to 16ft diameter fan that makes it “hard to even conjure up a solution on what to do with blade out…and when you lose a blade all kinds of bad things happen and we have yet to figure out a solution for it. And quite frankly, can’t conjure up a solution for it.

The risk of losing a blade, adds Bair, is low enough that its acceptable however “every time a blade comes off a propeller airplane the airplane is lost and we just won’t do that. Having a single thread failure that can cause an airplane to be lost, we just won’t do it. So we just don’t see that as a solvable problem.”

Bair concedes “These are going to be conventional looking engines and they’re going to be conventional looking airplanes. Tube and wing has been around for a long time for lots of really good reasons. It’s very very efficient way to fly stuff around, especially people.”

What do you build it out of?

As the general configuration of the aircraft takes shape, Bair says the material decisions remain “up in the air” with an all-composite, all-metallic or some hybrid of the two being evaluated. Boeing selected a majority-composite design for the 787, with both the wing and fuselage made of carbon fiber.

“We want to try and take advantage of everything we’ve learned on the ’87′, but this is a different airplane, different market segment, different mission rules, different requirements than an ’87′, so we have to make sure we don’t jump to a conclusion to understand what the answer is.

“So the other thing that happened is since we picked the materials set on the ’87′, the aluminum folks did not go to sleep, so there are more choices now than when we made the decision on the ’87′, so we have to methodically go through that and what that might mean.”

One consideration Bair considers “overblown” is the impact of ramp rash – or accidental impacts from ground handling – on a composite airframe. Compared to a long-range jetliner, a narrowbody aircraft in a high cycle environment spends more time exposed on the ramp in the course of a day, increasing the chance of potential damage.

“People’s initial reaction to composites were based on their experience with things like flaps and composite movable edges which are honeycomb laminates and they’re delicate. They can get damaged and they’re difficult to repair, the built up laminates that we’ve done on the ’87′ are actually harder to damage than aluminum, and we have dropped stuff on these things more often than you can imagine. So they’re harder to damage than aluminum…in some ways they’re easier to repair than aluminum. “

Yet at the same time, Bair says, all the skin thicknesses on the 787 are sized to absorb an impact, either by hail or baggage carts: “Which means if that’s how thick it has to be on a big airplane it needs to be that thick on a little airplane. So there’s sort of diminishing returns in terms of efficiency.”

11 Responses to Clean-Sheet – Boeing’s all-new jet: Configuration and Materials

  1. Jon Ostrower March 1, 2011 at 8:27 am #


  2. SteinarN March 1, 2011 at 9:42 am #

    It will be very interesting to follow this development.
    As I understand it, composites does not scale down very well, so how much lighter is it possible to make a composite narrowbody compared to an aluminum one? Will it be worth it at all or will it be a new aluminum narrowbody instead?

    Anyway, it seems like the Boeing engineers is set for a busy deacde with the 787 derivatives, now the new narrowbody and possibly some major upgrade to the 777, partly in response to the A350. Interesting times indeed

  3. Tom Bower March 1, 2011 at 9:46 am #

    I would vote for a 7 abreast seating configuration. It gives you B-767 type comfort, saves 5 to 10 minutes on each loading and unloading operation and it increases the overhead storage capacity by 60+% so that each passenger can readily find space to store their luggage.

    The wide oval fuselage cross section could be 16’6″ wide and 14’6″ high. It would feature two LD3-45 containers side by side with a vertical structural wall between the two containers. The vertical structural wall would be designed to collapse at a controlled rate to protect the passengers in the event of a crash. Boeing already has a patent application submitted for the wide oval fuselage so they should turn it into a patented design advantage over Airbus.

    I would envision a family of aircraft with one fuselage cross section, four fuselage lengths and two different wings.

    The base model, the B-797-100 would seat 150 passengers at a 32″ pitch, have a 118′ wingspan and feature a 3200 NM range. It is a true B-737-700 replacement.

    The next model, the B-797-300, would retain the 118′ wing and stretch the fuselage 23′ to expand the seating capacity to 200 passengers at a 32″ pitch. The B-797-300 would trade range for seating capacity and have a maximum range of 2200 NM. This aircraft is a MD-80 and MD-90 series replacement.

    The B-797-500 is designed as a B-757-200 replacement with a maximum range of 4500 NM for up to 10 hours of flying with a single crew. The B-797-500 would have a high aspect wing with 150′ wingspan and a 32 degree wing-sweep to permit M.85 cruise. The B 797-500 would have a dual class seating capacity of 200 seats.

    The B 797-700 would stretch the B-797-500 by 23′ increasing the seating capacity to 250 passengers. The B-797-700 would trade range for seating capacity but it would still have a range of 3700 NM permitting it to be a trans Atlantic aircraft.

    Boeing is going to have get innovative on the aerodynamic efficiency of the new B-797 series. I suggest Boeing investigate a Goldschmied Propulsor in which a boundary layer ingestion ring completely circling the fuselage is positioned just aft of the rear pressure bulkhead. The boundary layer air would be sucked into an electric duct fan positioned in the rear of the tail-cone. Goldschmied’s research predicts that the resulting Pressure Thrust generated by this design could yield a 25% total power reduction and thus provide a quantum leap in aerodynamic efficiency.

    Over to you, Boeing.

  4. Guru Josh March 1, 2011 at 10:25 am #


    I couldn’t get through for quite some time. Assumed I was rejected. Now I see you are checking the functionality. Technical glitch?

  5. TL March 2, 2011 at 10:53 pm #

    Didn’t the ‘market’ tell us that it didn’t want re-engined anything, A320 included? Despite this, the Neu seem to be selling well already.

    Maybe this is a case of wishful thinking over reality, the wish being shiny and new, reality being (relatively) short term delivery of a relatively low risk and much more efficient machine when it is becoming more clear that high oil prices will be sustained in future and may well climb. Current events in N.A. & Gulf show how jittery (unreasonably methinks) the ‘markets’ can be.

    Kudos to Airbus for cupping its ovoids and going for re-engining. I’ve a feeling that though not a direct competitor, the Sukhoi Superjet will do well… Here’s also hoping that someone also has the courage to develop a something different from tube-and-wing design (like the Eko-jet).

  6. snogglethorpe March 3, 2011 at 5:21 am #

    Note that the tradeoffs are different for the A320 and the 737, so what might work for Airbus, may not be the right thing for Boeing in this case…

  7. Frequent Traveller March 3, 2011 at 6:45 am #

    Mike Bair knows he needs to keep the fire under the 737+ kettle : 2019-20 is far away and in the very short term, the 737NG Series are threatened by a broadside from the H2XQR Series of TwinAisleFeeders who are attacking Boeing’s Bread’n-Butter sales star on its Achille’s Heel. Mike Bair is fully aware that an H3XQR Series retaliation is not a good strategy, hampered as Boeing’s feeders are with an ironball ground turn-around penalty of the 737NG’s bulk-loaded cargo holds. The idea of TwinAisleFeeders, to promote a new “Groundworthiness Certificate” for Civil Air Transport aircraft, is paving the way for H2XQR Series Quick Rotation twin aisle feeders (with or without NEO pending Customer preference), see

    By setting the EADS Airbus assembly lines in Germany and China to full steam, any further walzing by Mike’s team will mean 500+ lost sales per annum… over 9 years till 2020, that’s adding up to 4000+ units : will Boeing be ready in time to contain a major sales bleed in favour of the Winner combination [H2XQR Series + A32X Series]?

  8. RH March 9, 2011 at 5:48 pm #

    When Boeing is ready to get real they can come talk to me all this is boring same old planes different year

  9. james Raper March 11, 2011 at 2:25 am #

    Don’t you know that Boeing B 737 series are too low to accommodate new efficient engines? So Boeing have to build new airplane, instead of emulating Airbus neo’s.catastrophe for Boeing ahead.

  10. JC April 10, 2011 at 3:10 am #

    With income from 737, 787, 747-8F, 747-8i flood in like crazy, Boeing can afford to do both:

    1. Give 737 a new pair of efficient, composite wings to accommodate to upcoming new engines, while retaining the existing fuselage with its lovely interior–by 2016.

    2. A 797 to fill the gap between 737 and 787, with elliptical, twin-asle, 2-3-2 composite fuselage–by 2020.

  11. le bon vivant July 1, 2011 at 5:22 am #

    Boeing is a company ran by people who cannot think in business terms. Their engineers are brilliants but the business guys are clueless, clueless,clueless.
    This is why airbus has over taken them as the World no 1 in commercial aircraft.

    - Fact: Airbus has a factory in China producing A320 and Boeing who started well before airbus has None. This masterclass business strategy allow chineese airlines to identify with the A320 as a chineese built product.

    -Fact: Airbus produces more aircraft per year than boeing and the gap in number of deliveries is getting bigger with every passing year.

    -Fact: If the market does not want an NEO plane why has airbus racked in 1000+ orders of A320NEO vs some pathetic 100+ for the 737. Boeing must be talking about a market that only them know about.

    -Fact: If beoing was so inovative as they want us to believe why did they have to wait 42years to give a significant upgrade to the 747? Inspite all the hype around the 747 it cannot match the A380 in range, cost of mile per seat and operation cost. The 747 has no clear advantage over the A380 to compel airliners to choose it.

    -Fact: Boeing has failed to produce an aircraft that competes with the A330-300 and thus surendered the medium haul market to Airbus.

    -Fact: if the new airplane is not a replacement of the 737, why don’t they do a 737NEO as a short term option and then the NSA witch will cover a different market segment than the 737.

    In conclusion, Airbus has outsmarted boeing in all fronts. What ever boeing decides,its ability to compete with airbus is questionable.