Could an NMA be made good enough? Part 6

By Bjorn Fehrm

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Introduction

April 27, 2017, © Leeham Co.: We have in several articles gone through the sizing of an NMA (New Midrange Aircraft). We looked at the fuselage, cabin, wings and engines. Now we will sum the exercises and look at the performance of the resulting aircraft.

Boeing is seriously considering launching an NMA. The key to the launch decision will be the airplane’s economics: for development and production as well as operation.

The idea is the NMA shall have “twin aisle comfort with single aisle economics.” We will now use or performance model to analyze if the final aircraft has these characteristics.

Summary:

  • An NMA designed to the principles in our articles will have a seven abreast dual aisle cabin. The cabin will increase passenger comfort in the 200 to 260 seat range and speed ground operations.
  • Careful design of the fuselage, paired with a modern wing and engines, would produce an NMA with “dual aisle comfort and single aisle economics.”

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7M7 is key to Boeing’s future

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Introduction

An enthusiast’s concept of the Boeing 797. Image via Google.

April 24, 2017, © Leeham Co.: Boeing faces growing challenges this year as airplane sales slow, production of the 777 Classic declines, its new Global Services unit prepares to formally launch and a decision whether to authorize a sales offering for the New Midrange Airplane looms.

We’ve spent a lot of time covering slowing sales and declining 777 production. Tomorrow, we’ll have a special report on the ambitious Global Services strategy.

We’ve also spent a lot of time on the Boeing NMA. LNC’s Bjorn Fehrm last week presented number three in a paywall series on the NMA, looking at it from a technical viewpoint. We’ll take a look at it from a strategic point of view today.

Summary
  • There is a demand for the NMA that is commercially viable.
  • Middle of the Market sector is larger than typically defined.
  • 7M7 is key to Boeing’s future.

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Could an NMA be made good enough? Part 5

By Bjorn Fehrm

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Introduction

April 20, 2017, © Leeham Co.: After defining the fuselage and wings, it’s now time for the engines.  We go through the sizing criteria for engines for airliners and find the size of engine that is needed for the NMA.

The NMA will need engines which are larger than the single aisle engines for Airbus’ A320neo and Boeing’s 737 MAX. But they will be smaller than the next size up for modern engines, the GEnx-2B for Boeing’s 747-8.

Figure 1. The NMA takes more and more the shape of a 767 replacement (A United 767-200). Source: United

This means the NMA will need new engines, at least 50% larger than the present engines designed for A320neo and 737 MAX.

Summary:

  • An NMA engine will be sized by V2 safety speed or Maximum Continuous Thrust (MCT) criteria.
  • The normal Top of Climb (ToC) sizing point will be less stressing for a twin engine airliner like NMA.

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Could an NMA be made good enough, Part 4?

By Bjorn Fehrm

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Introduction

April 13, 2017, © Leeham Co.: Last week we finished the sizing of the fuselage for an NMA design. Now we continue with the wing. We go through the key parameters that will decide the performance of the wing and the aircraft.

The NMA is a critical design case. The performance envelope has to be just right. Too high and the economics of the aircraft won’t work, both for purchase price and operational costs.

Figure 1. The NMA takes more and more the shape of a 767 replacement (A United 767-200). Source: United

Summary:
  • Wing design is the mixing of conflicting requirements to a successful compromise.
  • The NMA wing will use the design principles of the Boeing 787/777X wings but will be different in area, size and plan-form.
  • The wing is sizing the engines, something we will look at in the next article.

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Could an NMA be made good enough, Part 3?

By Bjorn Fehrm

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Introduction

April 6, 2017, © Leeham Co.: After sizing the cabin of the NMA, the time has now come to size the fuselage. Can a fuselage be designed that gives an NMA “dual aisle comfort with single aisle economics”?

Figure 1. The NMA takes more and more the shape of a 767 replacement (A United 767-200). Source: United

We will investigate the dimensions, the drag and the weight of an NMA fuselage. It will be based on the cabin and design techniques we described in Part 2. We then compare the efficiency of the result with the fuselages of the Airbus A321LR and Boeing 767. This will show if the necessary efficiency can be achieved.

Summary:

  • It’s possible to design a dual aisle fuselage with the same perimeter per seat abreast as a single aisle fuselage.
  • This will make the central, cylindrical, section have competitive weight and drag characteristics.
  • The larger diameter of the dual aisle fuselage will increase the size of the tapered front and rear sections however.
  • It’s still possible for an NMA fuselage to be as weight-efficient as a single aisle fuselage, measured per transported passenger.

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Could an NMA be made good enough, Part 2?

By Bjorn Fehrm

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Introduction

April 3, 2017, © Leeham Co.: In the first part of our investigation on how good an NMA can be, we explored low weight and drag fuselage design. We will now continue with the design consequences for the fuselage construction and the cabin.

What drives whether one goes for an Aluminum or CFRP (Carbon Fiber Reinforced Polymer) fuselage?

Figure 1. The NMA takes more and more the shape of a 767 replacement (A United 767-200 pictured). Source: United.

What will be the typical dimensions for an NMA fuselage and what will be passenger capacities?

Summary:

  • An elliptical fuselage will force a CFRP design.
  • The fuselage door configuration will be critical for cabin capacity and flexibility.

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Naming games

March 31, 2017 (c) Leeham Co.: With the likelihood appearing greater and great Boeing will launch a new, middle of the market sector airplane, what’s the name

Is “A360” a name for the next Airbus aircraft? Or would it be the butt of jokes? Rendering via Google images.

going to be?

Steven Udvar-Hazy, chairman of Air Lease Corp, already calls it the 797. We agree, though until this is a done deal, we’re calling it the 7M7 while in development.

If Airbus responds with a stretched A321neo–anything but a certain prospect–the working title among the press has long been A322. Airbus officials have occasionally called it the A321 Plus-Plus, a name that will hardly roll off the tongue.

If Airbus were to respond with a new twin-aisle, either smaller than the A330-200/800 (which aren’t selling these days) or about the same size, what would this be called? Skipping to A400 doesn’t work: the name is taken by the A400M, which in any event is a snake-bitten name.

Then, what will the replacements for the Boeing 737 and Airbus A320 be called.

It’s already assumed “797” is the name of the widely expected Boeing middle of the market airplane. Rendering via Google images.

For Boeing, the “797” runs out the string of 7 Series choices. For Airbus, folklore says it rejected the name “A360” because of the jokes that would be made about the airplane flying in circles if an issue required a return from its takeoff point. According to the same folklore, “A370” was rejected because the “7” harks to Boeing’s 7 Series.

So: just for fun, let’s have some naming contests.

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Is there an NMA gap?

By Bjorn Fehrm

March 21, 2017, ©. Leeham Co: The NMA (New Mid-range Aircraft), or, as it’s called more and more, the Boeing 797, is hot. The potential buyers at the recent ISTAT meeting in San Diego urged Boeing to take the decision and get it done.

At the same meeting Airbus responds, “Any NMA gap is covered. Our A321neo and A330-800 is available and and no new aircraft is needed.”

Time to look at who’s right. Is there an NMA gap or not? Is there a difference in how Airbus’ and Boeing’s product lineups cover the market? Read more

Top 10 Leeham News stories of 2016

 Dec. 15, 2016, © Leeham Co.: The story about a Boeing official who asserted that the Airbus widebody strategy is a “mess” proved to be LNC’s most read story of 2016.

Our second most-read story is why the 787-8 is no longer favored by Boeing.

We list our Top 10 posts each year as we head for a wrap. LNC plans to finish 2016 on Dec. 23, returning Jan. 3, unless there is major, breaking news.

Here are the Top 10 LNC posts in 2016:

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Peeking into Boeing’s future airplanes

Oct. 18, 2016, © Leeham Co.: It was a rare look into potential future airplanes and passenger experience by Boeing, which is known for keeping these topics close to

Mike Sinnett, VP Product Development for Boeing. Taking 787 technologies and enhancing them for future airplanes. Photo via Google images.

Mike Sinnett, VP Product Development for Boeing. Taking 787 technologies and enhancing them for future airplanes. Photo via Google images.

its chest.

Mike Sinnett, VP of Product Development for Boeing Commercial Airplanes, last week gave an audience of nearly 250 people attending the annual Governor’s Conference organized by the Aerospace Futures Alliance, a look at some of the concepts Boeing is studying. Some may evolve into actual products and some may not, he said.

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