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Boeing's 737 family and its future

Started by Jeroen Hoppenbrouwers, Thu, 14 Mar 2019 11:45

Jeroen Hoppenbrouwers

Pure speculative thread, not about politics or lives, but about commercial and technical things.

Suppose, Boeing has overreached the technical abilities of the 737 airframe from 1969 and finally is forced to come up with a new design, call it the 7N7 for this thread. A new, single-aisle, 6-abreast, 120-230 capable family design like the A320 family that can and will range from just above Embraer to just below 787.

This of course would hurt immensely, maybe even more so than Airbus' A380 adventure. The 737, after all, is Boeing's cash cow.

But, suppose Boeing is going to do it. From scratch, with 787 and 777X tech readily available, and an agressive programme to beat the A320 family where it hurts.

What would you expect Boeing would come up with?


Hoppie

Toga

Wasn't the 797 supposed to be just that?

Jeroen Hoppenbrouwers

The 797 was intended to be just above the 737, replacing the 757/767. But now see it with a potential sudden death of the 737 MAX (and by extension NG) lines. Boeing needs a design that starts at 120 seats, not 225.

beat578

Seeing how long it took to develop the Dreamliner and seeing that the MAX is kind of the cashcow, I wonder how they can fill the financial gap between the decision of developing a new plane and the first orders.
The Dreamliner is an amazing plane, I could enjoy a flight last year, so Boeing for sure is capable of building great and amazing planes, but I wonder how you fund such a development.

localiser

The 787-9 has suffered from huge engine reliability issues. N.B. fuel efficiency and therefore engine manufacturers are a major part of such a modern new design.

Hardy Heinlin



Toga

Quotehttps://www.youtube.com/watch?v=rvkEpstd9os&t=74s

I wonder if the findings in this doc are starting to manifest themselves. You get what you pay for!

Will

Beyond just more fuel efficient engines, better lightweight but durable structural materials, and improved ease of maintenance, I don't have any ideas.

The really neat things -- like a cockpit with a truly enhanced user experience - wouldn't earn them any extra money, so we'll never see it.

My new car has a completely digital dashboard. No speedometer with a mechanical needle anymore, it's just a TV screen. The innovation is really nice, and the driver experience is much, much better than even a 787 (in terms of ergonomic and UX design, that is, not necessarily in terms of gravitas and fun). So an updated cockpit user experience would be greatly appreciated. But... not going to happen.
Will /Chicago /USA

Jeroen Hoppenbrouwers

Quote from: beat578 on Thu, 14 Mar 2019 14:28
The Dreamliner is an amazing plane, I could enjoy a flight last year, so Boeing for sure is capable of building great and amazing planes, but I wonder how you fund such a development.
Traditionally, large aeronautical companies fund this by military contracts for other stuff. Boeing is so big, their commercial aircraft division does not need to remain profitable at all times, they can afford gaps. Will investors like it? Some investors will. Others won't. Business as usual.

Hoppie

IefCooreman

I believe this is more a discussion for the financial institutes. Boeing wanted to start from 0 but changed minds on request of customers because it would take too much time and financially the risk was too big (with all the investments in the "from scratch"-787)

I wouldn't be surprised if both Boeing and Airbus would announce this project around the same time.

If you want to know what it will look like, from a systems point of view it would be more interesting to look at the 787 developments (fly-by-wire, more electrical power based, integrated systems... so yes, flying e-bikes is not that far off :-))

skelsey

Quote from: Will on Thu, 14 Mar 2019 19:46My new car has a completely digital dashboard. No speedometer with a mechanical needle anymore, it's just a TV screen. The innovation is really nice, and the driver experience is much, much better than even a 787 (in terms of ergonomic and UX design, that is, not necessarily in terms of gravitas and fun).

My car has a digital dashboard too - the interesting thing I found was that I had to change the presentation from the default (which had a large tachometer surrounding a digital speed readout) to a more traditional representation of a round dial speedo with a needle - I found the digital speed readout almost hypnotic and very difficult to 'scan' quickly as one had to read the numbers - not only that, but to get any sensense of rate information your eyes had to linger on the digits even longer. The result was I found myself staring at the speedo almost more than I was looking out at the road, which clearly was not a good thing!

The 'traditional' needle presentation, by contrast, allows a lot more information to be taken in with a quick sweep of the eyes. Interesting and relevant to the way in which information is presented in aircraft glass cockpits as well - whilst clearly glass provides advantages in many areas, I can see how the 'traditional' presentations can have benefits too!

Hardy Heinlin

Trends are also shown in glass cockpits: The compass disc turns, the speed and altitude tapes scroll. The glass instruments are way more ergonomic than those in cars, I think.

In addition to the moving tapes, the digital indications also scroll -- and that with a resolution of at least 0.1 knot.

Within the scrolling system of the airspeed digits there's another well-designed ergonomic detail: The 10-knot digits have greater spatial intervals than the 1-knot digits.

E.g. when the speed is 139.5, the digits within the "current speed" window will not be positioned like this:

14
   9
13

... but rather like this:

14
   0
   9
13

I cannot show it exactly here in text form. The "14" should be half a line height lower, and the "13" half a line height higher.

In the first example, it is not clear whether the "9" belongs to the "13" or to the "14". It may temporarily look like 149 instead of 139.

So the instrument designers added some space between the 10-knot increments. This additional space only becomes visible when the 1-knot digits scroll between 0 and 9 or vice versa.

This digital readout window actually resembles a zoom lense that enlarges the smaller digits that are on the tape.

The designers also put a lot of thoughts into the motion rates of the indications. If the instrument range is too small, (A) you cannot plan, and (B) the indication will move too fast. Vice versa, if the range is too large, you can hardly see any trends. -- Their final design is perfectly balanced (in my opinion). The typical motion rate of the airspeed tape is nearly equal to that of the altitude tape. E.g. when you decelerate at 1 kt per sec during idle descent while the sinkrate is 500 fpm as per ATC minimum, the tapes left and right will nicely scroll at almost the same rate, and so you can anticipate the target points at 240 KIAS and 10000 feet on the left and right tapes, with the attitude indicator's horizon line almost at the height of the tape windows.

I'm not a car expert, but such details are not included in the design of car instruments, I think. Not yet. Maybe later. I guess they put more weight on the aesthetical aspect of the car's displays. In my car the instruments are red which is good at night (telescope users know what I mean). And the text display on my radio in the center console is also red  -- by default. For aesthetical consistency. But I have changed the text display to green (with a hidden switch) because that red text distracts me; it looks like a red alert. So, all in all, my car cockpit looks ugly, but the color mix is more ergonomic for me.


Cheers,

|-|ardy

Will

My car has options to select on the dashboard for the speed readout, but all of the options have the speed presented as a number in the middle of a graduated ring that shows trends. It's pretty intuitive.

The GPS also knows the speed limit of the road you're on, so the speed limit is marked with a red line on the ring. That's pretty cool.

I agree with the value of trend information, so I enjoy the fact that the ring is there. The car has a heads up display as well, but that only has the number for the speed and no trend information is available other than just how fast the number is changing. Not optimal.
Will /Chicago /USA

Jeroen Hoppenbrouwers

By the way does somebody know in reasonable detail why the Airbus 320 family seems not to have these issues with slinging new engines under? More space? Already full FBW so easier to correct?

Markus Vitzethum

Of course, I don't "know" but there are plenty of references in literature (e.g. in Joe Sutter's book; he was one of the key persons in the defining the 737 layout)  that one of the initial design goals of the original 737-100 was to allow loading directly by the ground handling personnel without any extra ground handling equipment.

This dictated that the fuselage was close to the ground (comparable to regional jets) and thus a rather short gear. The original engines (long and thin) fitted under the wing, but already back then Sutter had to move the original engines up into the wing root.

The drawback of the initial design with short gear is a limitation regarding larger engines (already the 737 "classic" had non-circular inlets) and fuselage stretching.

Apparently, the A320 - probably already planned with the A321 stretch on the drawing boards - sits higher of the ground and does not have this limitation.

Markus

Jeroen Hoppenbrouwers

Reviving this thread with all recent developments.

MAX is in more trouble than expected. Software not at fault, despite extensive outsourcing, but system design and safety analysis flawed at best. Possibly some criminally punishable neglect here and there. Additional inspections revealed potentially unsuitable hardware for the real safety criticality of MCAS. The deeper they dig, the more they find.

787 cert process is now under investigation, too. Systemic failures in the safety analysis are slowly appearing. Despite the FAA's extensive rules on outsourcing, people are unhappy in hindsight. Rumours about Boeing having fired many, if not too many experienced senior engineers to cut costs.

What's next?


Hoppie

ahaka

I hope not the 747-8...

I got to fly a couple of times with the MAX before they got grounded. I fully trusted its the best 737 version ever. Kind of frightening to know about such serious flaws and possible neglect afterwards...

Antti

beat578

Well, The 777 and the 787 have been the last planes developped from scratch. And I trust in the 787, I read a lot about and have been flying in one already. I geuss, that plane really really is as good as it's been told. So why not take best parts from both planes and put them into a new smaller concept?

They should learn from Airbus: If they take the cockpit out of the 787, shrink it (but still make it alike) they could get the airlines that already orderes those 1400 dreamliners. they could use the same crew with minimum additional training sessions.

So i would try to build a "baby dreamliner"...

Jeroen Hoppenbrouwers

Same plane tech, possibly. Same crew, I am not so sure. Not only would the differences be too big to bridge (the aircraft are really of a different size category), but also since long-haul and short-haul schedules and careers don't match. However just as I think (presume, guess) that cross-training from a 757 to a 777 is less of a step than from a 757 to a 330, keeping a common flight deck definitely does have its advantages.

If Boeing bangs its head against the wall a few times and then decides to actually do a 737 size new plane using latest tech around (5-8 years and 10 billion dollars), Airbus will have to move. The neo series won't be able to beat that. But will Boeing dare? Are they practically forced to jump into the deep end anyway?

Hoppie