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Newbiepilot
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Re: 737 with new wing, landing gear potential

Mon Jun 21, 2021 1:02 pm

Aesma wrote:
Weatherwatcher1 wrote:
IADFCO wrote:
The only way I see for a significantly longer landing gear on the 737 is to remove it from inside the wing and move it to some sort of pod C-17-style, without otherwise changing the wing, and changing the central structure as little as possible. This would be major surgery, and not cheap. The only mitigating factor would be that it would not substantially alter the flight loads.


The trunion could be moved outward and lengthen the gear.

I think what people don’t realize is that the shorter gear is also an asset. The shorter gear alleviates the weight and complexity associated with overwinter slides. It also simplifies cargo loading and provides ground access to more panels without lifts or ladders. All of that is helpful to speed up turns.


If Boeing loses that asset but has a more modern, more efficient plane, would they lose sales ? Since no competitor has that asset anyway ?


I think I view the situation differently. How much more efficiency is to be gained by a larger fan diameter vs the efficiency lost by having the added weight of longer gear, overwing slides, powered cargo doors, etc? Engineering is about compromises. Airbus has gone for a larger fan with taller gear, powered cargo doors, overwing slides, etc, just because Airbus did it doesn’t mean it is better.

A and B do look at each other when developing new proposals. If we look in the flight deck, the two have very similar capability evolution over time (RNAV, CPDLC, HUD etc), but Airbus chose to keep the 6 small primary flight displays instead of having more modern larger displays like on the 737MAX or A220. The A321neo copied the 737-900ER exit door configuration. The 737-10 introduced a new main landing gear for increased rotation angle. The 737 has always had shorter gear and a smaller fan, but the 737NG sold awfully well despite having a smaller fan than the A320 when Boeing lengthened the main gear in the 737NG. Boeing lengthened the nose gear on the 737MAX. If a bigger fan justified itself, Boeing could have raised the main gear again on the 737MAX by moving the grunion outboard, but they chose not to.

My point is that The A320 and 737 are both evolving with time. The criteria for how both evaluate upgrades aren’t the same. Just because one is different than the other doesn’t mean that specific upgrade makes sense on the other.
 
WIederling
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Re: 737 with new wing, landing gear potential

Mon Jun 21, 2021 1:24 pm

ClipperMonsoon wrote:
hiflyeras wrote:
What it really needs is a wider fuselage in addition so so many other things as you mentioned. As long as Boeing relies on the 707 specs it'll never see success over Airbus.


And what 707 specs might that be, the upper fuselage width?, I guess it goes to show what a fantastic jet was built by Boeing over 64 years ago and still flying..


It is still flying because Boeing managed to bypass the majority of upmarked certification requirements.
It is a banged up 1950 relic with no real concept.
( you see similar in the US small trucks domain. 1930 relics. unsafe at any speed :-)

compare to the Airbus FBW concept that presents a homogeneous flying experience over the type range.
( it is not the FBW alone but the concept of an abstract flying model that all types adhere to ( mostly ))
 
Newbiepilot
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Re: 737 with new wing, landing gear potential

Mon Jun 21, 2021 1:36 pm

WIederling wrote:
ClipperMonsoon wrote:
hiflyeras wrote:
What it really needs is a wider fuselage in addition so so many other things as you mentioned. As long as Boeing relies on the 707 specs it'll never see success over Airbus.


And what 707 specs might that be, the upper fuselage width?, I guess it goes to show what a fantastic jet was built by Boeing over 64 years ago and still flying..


It is still flying because Boeing managed to bypass the majority of upmarked certification requirements.
It is a banged up 1950 relic with no real concept.
( you see similar in the US small trucks domain. 1930 relics. unsafe at any speed :-)

compare to the Airbus FBW concept that presents a homogeneous flying experience over the type range.
( it is not the FBW alone but the concept of an abstract flying model that all types adhere to ( mostly ))


Can you please list the “bypassed unmarked certification requirements”. Can you name a few CFRs that the 737 bypassed or are your comment general hyperbole?
 
WIederling
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Re: 737 with new wing, landing gear potential

Mon Jun 21, 2021 1:55 pm

Newbiepilot wrote:
[Can you please list the “bypassed unmarked certification requirements”. Can you name a few CFRs that the 737 bypassed or are your comment general hyperbole?


There is a "deforming" copy error in your question.


Can you prove that the 737MAX conforms to the same obstacle clearance and single engine out requirements the A320 is certified for?
Same for max fuselage g forces. ( seats today have the higher crash resistance but the fuselage they are attached to not.)
Last edited by WIederling on Mon Jun 21, 2021 2:01 pm, edited 1 time in total.
 
GalaxyFlyer
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Re: 737 with new wing, landing gear potential

Mon Jun 21, 2021 1:57 pm

WIederling wrote:
ClipperMonsoon wrote:
hiflyeras wrote:
What it really needs is a wider fuselage in addition so so many other things as you mentioned. As long as Boeing relies on the 707 specs it'll never see success over Airbus.


And what 707 specs might that be, the upper fuselage width?, I guess it goes to show what a fantastic jet was built by Boeing over 64 years ago and still flying..


It is still flying because Boeing managed to bypass the majority of upmarked certification requirements.
It is a banged up 1950 relic with no real concept.
( you see similar in the US small trucks domain. 1930 relics. unsafe at any speed :-)

compare to the Airbus FBW concept that presents a homogeneous flying experience over the type range.
( it is not the FBW alone but the concept of an abstract flying model that all types adhere to ( mostly ))


Care to provide details on our “1930s relic small trucks” while you’re researching non-existent CFRs.
 
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Polot
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Re: 737 with new wing, landing gear potential

Mon Jun 21, 2021 1:58 pm

WIederling wrote:
Can you prove that the 737MAX conforms to the same obstacle clearance and single engine out requirements the A320 is certified for?

Yes it is. The single engine out requirements are the same- the plane must be able to take off and fly with one engine.

I don’t know what you mean about obstacle clearance. The obstacle clearance is the same- the 737 either clears an obstacle or can’t, requiring weight reductions until it can or a different aircraft. It’s not like the 737 is allowed to fly closer to obstacles than the A320. There is no legal requirement on “obstacle clearance” performance that an aircraft is required to meet for certification. If an aircraft has terrible climb performance it will still be certified, although it’s commercial prospects may not be as attractive if heavily restricted everywhere.

With roughly the same weights, engine thrusts, and similar wing size between the 737 and A320 their “obstacle clearance” and engine out performance is broadly similar.
 
WIederling
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Re: 737 with new wing, landing gear potential

Mon Jun 21, 2021 2:49 pm

Polot wrote:
WIederling wrote:
Can you prove that the 737MAX conforms to the same obstacle clearance and single engine out requirements the A320 is certified for?

Yes it is. The single engine out requirements are the same- the plane must be able to take off and fly with one engine.

I don’t know what you mean about obstacle clearance. The obstacle clearance is the same- the 737 either clears an obstacle or can’t, requiring weight reductions until it can or a different aircraft. It’s not like the 737 is allowed to fly closer to obstacles than the A320. There is no legal requirement on “obstacle clearance” performance that an aircraft is required to meet for certification. If an aircraft has terrible climb performance it will still be certified, although it’s commercial prospects may not be as attractive if heavily restricted everywhere.

With roughly the same weights, engine thrusts, and similar wing size between the 737 and A320 their “obstacle clearance” and engine out performance is broadly similar.


Balooney!

Just ahead of the A320 certification the minimum height
and the conditions under which to achieve those was increased.
you may want to look into this document:
https://www.smartcockpit.com/docs/Getti ... rmance.pdf ~p53
 
WIederling
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Re: 737 with new wing, landing gear potential

Mon Jun 21, 2021 3:13 pm

WIederling wrote:
Just ahead of the A320 certification the minimum height
and the conditions under which to achieve those was increased.
you may want to look into this document:
https://www.smartcockpit.com/docs/Getti ... rmance.pdf ~p53


grandfather clause applies for the NG and thus the MAX too:
https://www.flightglobal.com/airbus-cha ... 68.article
 
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Polot
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Re: 737 with new wing, landing gear potential

Mon Jun 21, 2021 3:16 pm

WIederling wrote:
Polot wrote:
WIederling wrote:
Can you prove that the 737MAX conforms to the same obstacle clearance and single engine out requirements the A320 is certified for?

Yes it is. The single engine out requirements are the same- the plane must be able to take off and fly with one engine.

I don’t know what you mean about obstacle clearance. The obstacle clearance is the same- the 737 either clears an obstacle or can’t, requiring weight reductions until it can or a different aircraft. It’s not like the 737 is allowed to fly closer to obstacles than the A320. There is no legal requirement on “obstacle clearance” performance that an aircraft is required to meet for certification. If an aircraft has terrible climb performance it will still be certified, although it’s commercial prospects may not be as attractive if heavily restricted everywhere.

With roughly the same weights, engine thrusts, and similar wing size between the 737 and A320 their “obstacle clearance” and engine out performance is broadly similar.


Balooney!

Just ahead of the A320 certification the minimum height
and the conditions under which to achieve those was increased.
you may want to look into this document:
https://www.smartcockpit.com/docs/Getti ... rmance.pdf ~p53

The only thing I see is related to accelerated-stop calculation changes that effect the payload certified. Which unfairly penalized newer aircraft so it was changed and later A320s recertified under new (and current) standard.

In any event because the 737NG/MAX has completely different wings and engines from prior versions it would have to conform to all takeoff/climb standards in place in the mid-late 90s.
 
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Polot
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Re: 737 with new wing, landing gear potential

Mon Jun 21, 2021 3:18 pm

WIederling wrote:
WIederling wrote:
Just ahead of the A320 certification the minimum height
and the conditions under which to achieve those was increased.
you may want to look into this document:
https://www.smartcockpit.com/docs/Getti ... rmance.pdf ~p53


grandfather clause applies for the NG and thus the MAX too:
https://www.flightglobal.com/airbus-cha ... 68.article

That just says Boeing was trying to get it grandfathered and that Airbus was challenging. It never says Boeing was successful. That article dates back to 2 years before the 737NG even first flew.
 
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Revelation
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Re: 737 with new wing, landing gear potential

Mon Jun 21, 2021 4:59 pm

gatechae wrote:
Revelation wrote:
One article I read said they have 767 cockpit sub-assemblies in them which are still made by Spirit in Wichita.

Those are used to ship the 777 S41 and 747 S41. The 767 S41 was previously also shipped in that method but is now integrated in ICT and shipped via dreamlifter to everett.

Very interesting!

Since the sub-topic is about the max width that can be shipped by rail, we should point out that section 41 is just the bit from the nose to just behind the cockpit windows so not the max fuse width of a wide body. If you open the large version of:



... the joint between S41 and the rest of the airplane is easy to see.

So, we still end up not really being able to ship anything much wider than the ~12 foot wide 737 fuse.

Aside: an interesting thread on section 41 from 15 years ago: viewtopic.php?t=415687

Man, that makes me feel old, it's right from the time I joined a.net and had already been a lurker for a few years before then...

And now, back to the A vs B willy-waiving...
Last edited by Revelation on Mon Jun 21, 2021 5:06 pm, edited 1 time in total.
 
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Revelation
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Re: 737 with new wing, landing gear potential

Mon Jun 21, 2021 5:15 pm

ClipperMonsoon wrote:
Find me one part on the new 737s that were made in the 50s, just one one, oh i see you want to compare AB, funny AB is just another company, has it's pros and cons just like Boeing, don't see why you are complaining, Boeing has had their hands full, while Airbus has way to many orders to keep up with, this in itself should make y'all happy enough, but i guess it's not, like i said there are absolutely no parts on 737s that were fabricated in the 50s.

We had an interesting thread here back in the old days where some of the Boeing old timers addressed this. They said that a lot of the basic things such as rivets were still based on specifications that went back to the B-29 (first large pressurized aluminum aircraft) never mind 707. They also claimed some very basic things such as rudder pedals were likely to be the exact same items going back that far, or at least their specifications were the same and maybe some of the materials used were modernized. Some things just stand the test of time.
 
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ClipperMonsoon
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Re: 737 with new wing, landing gear potential

Mon Jun 21, 2021 5:31 pm

Revelation wrote:
ClipperMonsoon wrote:
Find me one part on the new 737s that were made in the 50s, just one one, oh i see you want to compare AB, funny AB is just another company, has it's pros and cons just like Boeing, don't see why you are complaining, Boeing has had their hands full, while Airbus has way to many orders to keep up with, this in itself should make y'all happy enough, but i guess it's not, like i said there are absolutely no parts on 737s that were fabricated in the 50s.

We had an interesting thread here back in the old days where some of the Boeing old timers addressed this. They said that a lot of the basic things such as rivets were still based on specifications that went back to the B-29 (first large pressurized aluminum aircraft) never mind 707. They also claimed some very basic things such as rudder pedals were likely to be the exact same items going back that far, or at least their specifications were the same and maybe some of the materials used were modernized. Some things just stand the test of time.


Oh i believe you, i love talks with old timers, my FAA inspector/former boss had fantastic stories from the past, anyway back to the subject, the specs could be the same, but my point was that those materials weren't produced in the 50s, they maybe 50s specs. But they weren't fabricated back then and installed now. Seems no matter how much sense you make, some people are dead set in their ways.
 
Okcflyer
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Re: 737 with new wing, landing gear potential

Mon Jun 21, 2021 5:44 pm

There are a few misconceptions that are often repeated:

Claim 1) Boeing *wanted* to keep the old 737 control system as it's "cheaper", and airlines simply hold their nose and accept them as "second class" because they're cheaper.

Response: Boeing publically pushed for a new replacement model. Airlines themselves rejected/pushed back due to the high cut-over cost and disruption of moving to a completely new type. While it's not ideal, the large airlines decided it was better to advocate for an update of the "older" systems knowing the deficiencies then the costs of moving to a modern platform.

Claim 2) Maintaining the grandfather systems is cheaper and easier for Boeing, despite being less safe.

Response: Boeing spent billions of dollars doing small things the "hard way" in order to keep the legacy systems to maintain the common type rating. In the case of the MAX, for the about same amount of time/investment, they could have moved the aircraft to a FBW architecture which have yielded benefits including:

1) Reduced aerodynamic drag. They've had to implement multiple passive methods to meet certification criteria which induce drag and add weight.
2) Reduced wing strength/weight due to implementation of load alleviation and lower control loading possible. The MAX weight gain is proportionally higher than NEO despite the engines on the NEO being heavier.
3) Simplified control surfaces and rigging (reduces weight and drag, related to #3)
4) Eliminated dorsal fin (weight and drag reduction)
5) Simplified manufacturing process (less items, less tasks, etc)
6) Lighter systems - so many independent systems drives weight, plus the control cables and supports aren't exactly light either.

However, doing so would have required a whole new type rating and been a major disruptor to operators of NG fleets. These FBW gains did not offset by "commonality" costs. They're tangible but not enough.

FACT: It is/was possible to update the NG to MAX and maintain commonality with acceptable trade offs. It's unfortunate that Boeing completely botched what should have been an easy implementation of MCAS. Nothing is wrong with the concept of MCAS. The issue was with the execution and risk management.

Claim 3) Boeing may never move to a modern model.

Response: There will come a time when the costs of making the legacy equipment meet modern performance requirements exceeds the savings to keep the legacy type. Per WN and a couple other large 737 operators, the MAX vs NSA business case was not enough to justify this.

The industrialized manufacturing system of the 737 is massive and completely killing it and moving to "all new" may not be possible logistically or financially all at once. While the 737 fuse may not be the most efficient (double bubble, etc), it may need to carry forward with additional updates in order to greatly simplify conversion to the next model. Likewise, it may be possible to largely reuse existing tooling on a new fuse that's closely resembles the former, but had distinct improvements. Keep in mind there were rather large changes to how the fuse was manufactured between the classic and NG, which reduced manufacturing costs, improved fatigue life, saved weight while keeping some grandfathered items and maintaining the 737 type certificate (this is largely drive by systems and flight dynamics, not structural items)
 
mjoelnir
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Re: 737 with new wing, landing gear potential

Mon Jun 21, 2021 6:01 pm

Okcflyer wrote:
There are a few misconceptions that are often repeated:

Claim 1) Boeing *wanted* to keep the old 737 control system as it's "cheaper", and airlines simply hold their nose and accept them as "second class" because they're cheaper.

Response: Boeing publically pushed for a new replacement model. Airlines themselves rejected/pushed back due to the high cut-over cost and disruption of moving to a completely new type. While it's not ideal, the large airlines decided it was better to advocate for an update of the "older" systems knowing the deficiencies than the cost of moving to a modern platform. Boeing does not appear to be the heavy pusher behind keeping the old.

Claim 2) Maintaining the grandfather systems is cheaper and easier for Boeing, despite being less safe.

Response: Boeing spent billions of dollars doing small things the "hard way" in order to keep the legacy systems to maintain the common type rating. For the about same amount of time/investment, they could have moved the aircraft to a FBW architecture which have yielded benefits including:

1) Reduced aerodynamic drag. They've had to implement multiple passive methods to meet certification criteria which induce drag and add weight.
2) Reduced wing strength/weight due to implementation of load alleviation and lower control loading possible. The MAX weight gain is proportionally higher than NEO despite the engines on the NEO being heavier.
3) Simplified control surfaces and rigging (reduces weight and drag, related to #3)
4) Eliminated dorsal fin (weight and drag reduction)
5) Simplified manufacturing process (less items, less tasks, etc)
6) Lighter systems - so many independent systems drives weight, plus the control cables and supports aren't exactly light either.

However, these benefits were not offset by "commonality" argument. They're tangible but these switching costs are very massive.

FACT: It is/was possible to update the NG to MAX and maintain commonality with acceptable trade offs. It's unfortunate that Boeing completely botched what should have been an easy implementation of MCAS. Nothing is wrong with the concept of MCAS. The issue was with the execution.

Claim 3) Boeing will never move to a modern model.

Response: There will come a time when the costs of making the legacy equipment meet modern performance requirements exceeds the savings to keep the legacy type. Per WN and a couple other large 737 operators, the MAX vs NSA business case was not enough to justify this.

It's possible that smaller evolutionary changes are made. The industrialized manufacturing system of the 737 is massive and completely killing it and moving to "all new" may not be possible logistically or financially at once. While the 737 fuse may not be the most efficient (double bubble, etc), it may need to carry forward with additional updates in order to greatly simplify conversion to the next model. Likewise, it may be possible to largely reuse existing tooling on a new fuse that's closely resembles the former, but had distinct improvements.


to 1) let us talk about one airline, South West. And if customer wishes leads to bad decisions by the producer, it is still the producers problem.

to 2) Boeing should have updated to a FBW. Everybody else did. Even Embraer did it with the move from E series to E2 series. 2.5 % better fuel economy, just by moving to FBW apart from other changes (at Embraer).

to 3) Boeing has either move the 737 to a modern frame, with keeping the basics, but adding the things a modern airliner has, the FBW. Or alternatively bring a complete new frame. Both with the loss of commonality. Or Boeing has to live with a steadily shrinking market share.
Last edited by mjoelnir on Mon Jun 21, 2021 6:05 pm, edited 1 time in total.
 
jetstar
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Re: 737 with new wing, landing gear potential

Mon Jun 21, 2021 6:05 pm

The B-737 max is grandfathered under the original B-737 type certificate, start doing a lot of changes to the airframe and the FAA will require the airplane to be re-certified under today’s standards. At that point you might as well design a brand new airplane than try to incorporate today’s standards into a 1960’s technology airframe.

JetStar
 
Cdydatzigs
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Re: 737 with new wing, landing gear potential

Mon Jun 21, 2021 8:03 pm

Revelation wrote:
They said that a lot of the basic things such as rivets were still based on specifications that went back to the B-29 (first large pressurized aluminum aircraft) never mind 707. They also claimed some very basic things such as rudder pedals were likely to be the exact same items going back that far, or at least their specifications were the same and maybe some of the materials used were modernized. Some things just stand the test of time.


Doorknobs, hand trucks, wheel barrows, countless hand tools. If you design it the correct way the first time, no real changes will be needed in the future.
 
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ClipperMonsoon
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Re: 737 with new wing, landing gear potential

Mon Jun 21, 2021 9:08 pm

Cdydatzigs wrote:
Revelation wrote:
They said that a lot of the basic things such as rivets were still based on specifications that went back to the B-29 (first large pressurized aluminum aircraft) never mind 707. They also claimed some very basic things such as rudder pedals were likely to be the exact same items going back that far, or at least their specifications were the same and maybe some of the materials used were modernized. Some things just stand the test of time.


Doorknobs, hand trucks, wheel barrows, countless hand tools. If you design it the correct way the first time, no real changes will be needed in the future.

Accurate and simply put.
 
Speedy752
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Re: 737 with new wing, landing gear potential

Tue Jun 22, 2021 2:05 am

SEPilot wrote:
Yes, the 737 is over 50 years old. But the time and money to make a clean-sheet new plane does not seem to be there, and may never be because airlines cannot endure a multi-year period of low production that a new design would almost certainly entail. The A320 is newer but still old technology, and is similarly not likely to be replaced any time soon. The A320 does have one significant advantage over the 737 going forward; it can accommodate larger diameter engines. That would appear to put the 737 at an increasing disadvantage in the future. This is already apparent. While the 737NG maintained near parity with the A320, the NEO has jumped to a 60-40 advantage over the MAX. While most commentators have come to the conclusion that the MAX is the end of the road for the venerable 737, I am not sure that it has to be. There is little efficiency to be gained by a new fuselage, and as I understand it at this point a change to CFRP gains almost nothing on a narrowbody. Systems can be improved, but they have relatively little impact on operating costs.

What the 737 really needs is longer legs. This would require major changes to the wing structure, and would best be accomplished by a completely new wing. While this is a huge change, Boeing is doing it on the 777, and there is persistent talk of Airbus doing it for the proposed A322. Why not build a 737-11 with a new (likely CFRP) wing, longer gear and a redesigned nose that would allow a longer nose gear? Once this is certified and the bugs worked out the new wing and nose can be passed down to the smaller models, thus easing the transition and minimizing the time where production cannot keep up with demand.


Like maybe…a 757 type aircraft? LOL
 
mjoelnir
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Re: 737 with new wing, landing gear potential

Tue Jun 22, 2021 5:34 am

jetstar wrote:
The B-737 max is grandfathered under the original B-737 type certificate, start doing a lot of changes to the airframe and the FAA will require the airplane to be re-certified under today’s standards. At that point you might as well design a brand new airplane than try to incorporate today’s standards into a 1960’s technology airframe.

JetStar


So what? Should Airbus have kept the cockpit of the A310 when designing the A330 to be able to keep the same type certificate?

The point would be to keep the manufacturing line for the 737 that Boeing has and add the things that are needed to make it a more modern frame, that keeps to the modern rules. Boeing added EICAS for the P8 for example, but not for the MAX. If Embraer can move the E-Series to a FBW with the E2, why should Boeing not be able to move the 737 to an FBW. Yes they would need perhaps a new type certificate, but doing that for a 787 like cockpit could make it worth it.
 
DaCubbyBearBar
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Re: 737 with new wing, landing gear potential

Tue Jun 22, 2021 10:45 am

The MAX is the MAX that the 737 can do. How do you expect Boeing to spend another couple hundred million dollars to redo the wing and landing gear? It would take commonality out of parts and procedures, making it possibly more expensive on the maintenance side. It really needs a new engine if you are remaking it. Boeing will not be investing more time and money into this plane.
 
B764er
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Re: 737 with new wing, landing gear potential

Tue Jun 22, 2021 11:57 am

I agree with this comment above but it looks like the next 737 will look somewhat like the stillborn 757-100 and it will resemble the A320. I don't know if that is what Boeing wants. Hmm, it looks like at Boeing they have their hands full either way. Stay tuned.
 
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Faro
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Re: 737 with new wing, landing gear potential

Tue Jun 22, 2021 1:02 pm

Toenga wrote:
The 737 is a true aviation icon but it is already one iteration too many.
Sure it will continue to sell at discounted prices especially to airlines wishing to retain more commonality then the alternative offering.
The A 320 perhaps has a remaining viable iteration left but old technologies do in fact run out.
Now is the time to invest for both companies, in seriuous work for new air frames, in by far the biggest segment of the aviation market.



True to a certain extent...but what in actuality does a new fuselage bring compared with new wings + engines?...not much really...

I can see the argument for one more iteration, yes...the question would then become what will the next-plus-one 737-replacement be?...


Faro
 
texl1649
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Re: 737 with new wing, landing gear potential

Tue Jun 22, 2021 2:20 pm

Any new type certificate from Boeing or Airbus will be FBW and will have nothing to do with the present 737 frame, certainly. I think the goal will/must be to make them as absolutely crash proof/idiot proof as possible moving forward, and legacy 737 ratings/trim wheels etc. are…going away.
 
Elementalism
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Re: 737 with new wing, landing gear potential

Tue Jun 22, 2021 4:24 pm

SilverwingSpttr wrote:
I made a photoshop render of this concept a few months back and I'll happily share it here.

Image

Bottom plane is the trusted and reliable 757-200. We all know and love this plane, but she's had her time and is now old news, even with Delta's great cabins.

The top plane is what we may know as the 797. Here's what it features (in my mind):
-757-200 fuselage length and width
-757-200 gear height
-Modern style 'droop nose' like all other new planes
-Variable cabin door configurations (I-I-ii-I, I-I-I-I, and I-ii-I)
-Dreamliner-style simplified cockpit windows
-New wing
-MAX-style split-scimitar winglets
-LEAP/PW (or RR) engines rated in the 38,000-45,000lb thrust range
-Dreamliner-style horizontal stabilizer, vertical stabilizer, and tail cone.

Please keep in mind, when I say "757 fuselage length and width" those are just numeric values. This plane would by no means be a 757NG as that would make it a 757, which it is not. This would be an entirely new airplane that is 'inspired by' existing models. I cringe at the idea of another 737 model, especially now that we have a 737Max10 now, which is only about 10ft shorter than the 757-200.


757 really is a sexy plane.
 
Babyshark
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Re: 737 with new wing, landing gear potential

Tue Jun 22, 2021 4:31 pm

Elementalism wrote:

757 really is a sexy plane.


Sure, skinny and well… big engines.

But as a machine made to carry people around it’s too skinny. 737 just the same. They’re uncomfortable and sometimes miserable to ride in.

That fuselage needs to be retired.
 
Babyshark
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Re: 737 with new wing, landing gear potential

Tue Jun 22, 2021 4:40 pm

mjoelnir wrote:
jetstar wrote:
The B-737 max is grandfathered under the original B-737 type certificate, start doing a lot of changes to the airframe and the FAA will require the airplane to be re-certified under today’s standards. At that point you might as well design a brand new airplane than try to incorporate today’s standards into a 1960’s technology airframe.

JetStar


So what? Should Airbus have kept the cockpit of the A310 when designing the A330 to be able to keep the same type certificate?

The point would be to keep the manufacturing line for the 737 that Boeing has and add the things that are needed to make it a more modern frame, that keeps to the modern rules. Boeing added EICAS for the P8 for example, but not for the MAX. If Embraer can move the E-Series to a FBW with the E2, why should Boeing not be able to move the 737 to an FBW. Yes they would need perhaps a new type certificate, but doing that for a 787 like cockpit could make it worth it.


I would think Boeing has plenty of buildings available soon to set up new production lines.

The E-Series was already FBW.

Southwest would like to stop you at “perhaps a new type certificate” and remind you that no means no. Same type. 4ever.
 
reltney
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Re: 737 with new wing, landing gear potential

Tue Jun 22, 2021 4:58 pm

What it also needs is the 757 cockpit as originally proposed with the next generation 737 until SW screwed over the program insisting on the 1965 designed cockpit and overhead panel. It is amazing how SW sent back the 737 and Boeing.

I hope the MAX 10 can come closer to 757 approach speeds and takeoff performance than the -800.

Just to show how the 737 performs, when I bring a 757 into SNA, I have NO RESTRICTIONS. NADA!!! I fly a flap 25 approach with manual brakes and the plane with out any stopping effort can still turn off at taxiway E and my brake temps never go above 1 or 2... A 737 and even the 320 has a list of restriction, brake/flap settings settings and still battle hot brakes........what is wrong with picture!

Let’s hope for a clean easy test program..
 
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Revelation
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Re: 737 with new wing, landing gear potential

Tue Jun 22, 2021 5:15 pm

reltney wrote:
........what is wrong with picture!

Like it or not, economics plays a role and 757 lost out on that front a long time ago.

Sure it's great at SNA, it was built for restriction-free take offs at LGA so EA could serve Florida.

However for most situations it is over-built and the thrust it has for SNA and LGA doesn't matter during cruise.

It's economics were better than 727, but today they live on only because they are paid for.
 
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litz
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Re: 737 with new wing, landing gear potential

Tue Jun 22, 2021 5:21 pm

Revelation wrote:
FiscAutTecGarte wrote:
Is Boeing against a hard width limit for transporting fuselage sections by train from Spirit in Wichita? Would a fuselage some 6-12" wider be prohibitive? Was this perhaps the basis for considering maintaining the '37 fuselage in the 5G study?

I am NOT an expert but a little bit of reading suggests US rail cars normally don't exceed 10 ft 8 inches in width and the 12 foot plus width of 737 fuselages is already a challenge yet I'm not sure what the absolute limit would be.

There already are some cars used to ship airplane parts between Spirit and Boeing that are a bit bigger than the 737 fuse:

Image

Ref: https://trainsnscale.com/models-and-pro ... s-by-rail/

Apparently these are called 'skybox cars' in the rail industry.

You can see those cars mixed in with 737 fuses in the following photo:

Image

Ref: https://www.forbes.com/sites/danielreed ... customers/

They appear to be a bit taller and maybe a little bit wider but that's probably the limit. One article I read said they have 767 cockpit sub-assemblies in them which are still made by Spirit in Wichita.

The first link ( https://trainsnscale.com/models-and-pro ... s-by-rail/ ) has lots of cool info and pictures in it, many of them historical. I always wondered how the various pieces for a 747 got to KPAE. It shows a lot of different stuff from a lot of the different subcontractors.

It shows one of the 737 fuse cars unloaded so you can get an idea of its size.

Image

It seems fair to suggest you probably can't go much wider than the protective ring on the end of the flatbed.

The article also shows there is a purpose-built railroad from the Port of Everett to KPAE that handles extra-wide and extra-tall containers.

Image

I read a lot of stuff for the 747 came by sea. For instance I read a lot of the stuff came on barges from the Los Angeles / Long Beach area and was put onto barges to the Port of Everett. Presumably a lot of this came from the ex-Northrup plant owned by Triumph that recently produced the last 747 sections. Also a lot of the 777 pieces come via sea transport from Japan and trains transport the containers from the docs to KPAE.

Three very nerdy interests collide: airplanes, railroads and ships...


From the (iron) horse's mouth:

https://www.uprr.com/aboutup/maps/graph ... limits.pdf
 
Aptivaboy
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Re: 737 with new wing, landing gear potential

Tue Jun 22, 2021 6:15 pm

There was serious talk a few months ago about an enlarged SuperMax 737 that Boeing was investigating - think existing fuselage, but new nose, new empenage, and significant changes to the wings. Has there been any word on this? Or, will it remain in the realm of yet another Boeing study that will never make it to market?

I must agree with those arguing for a clean sheet design. The changes needed to simply alter the wings and lengthen the gear would result in a massive certification process given the severity of the changes. Boeing might as well start from scratch if its going to have to go through the entire certification process anyway.
 
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lightsaber
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Re: 737 with new wing, landing gear potential

Tue Jun 22, 2021 6:29 pm

Discuss the topic, not other users.

This is your warning.
 
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Aesma
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Re: 737 with new wing, landing gear potential

Wed Jun 23, 2021 1:11 am

When talking about parts for maintenance etc. If the 737 keeps the "same fuselage" but changes everything else, would there be any benefit ? The fuselage isn't really a spare part. The doors and windows maybe ? But you would probably want to upgrade them too.

The A300 and A330 have been mentioned, are there any parts in common between the two ?

As an aside, Airbus developed Laser Beam Welding for the A318 fuselage, that was also used on the A380. I guess that needed new certification, and I can't find sources saying it is now used on the rest of the A320 family, I wonder why.
 
9QCLI
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Re: 737 with new wing, landing gear potential

Wed Jun 23, 2021 10:27 am

Aesma wrote:
When talking about parts for maintenance etc. If the 737 keeps the "same fuselage" but changes everything else, would there be any benefit ? The fuselage isn't really a spare part. The doors and windows maybe ? But you would probably want to upgrade them too.

The A300 and A330 have been mentioned, are there any parts in common between the two ?




The benefits of keeping the existing 737 fuselage is to keep the supply chain intact to keep costs and risk low.
As to the A300/A330, I believe the whole fuselage and vertical fin was carried over.
 
mjoelnir
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Re: 737 with new wing, landing gear potential

Wed Jun 23, 2021 1:54 pm

Newbiepilot wrote:
WIederling wrote:
ClipperMonsoon wrote:

And what 707 specs might that be, the upper fuselage width?, I guess it goes to show what a fantastic jet was built by Boeing over 64 years ago and still flying..


It is still flying because Boeing managed to bypass the majority of upmarked certification requirements.
It is a banged up 1950 relic with no real concept.
( you see similar in the US small trucks domain. 1930 relics. unsafe at any speed :-)

compare to the Airbus FBW concept that presents a homogeneous flying experience over the type range.
( it is not the FBW alone but the concept of an abstract flying model that all types adhere to ( mostly ))


Can you please list the “bypassed unmarked certification requirements”. Can you name a few CFRs that the 737 bypassed or are your comment general hyperbole?


Let us start with EICAS. A requirement that the 757/767 fulfilled according to the regulation in force than (1981). We could continue with g forces the fuselage has to absorb. The list is long.
 
bob75013
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Re: 737 with new wing, landing gear potential

Wed Jun 23, 2021 2:31 pm

WIederling wrote:
Newbiepilot wrote:
[Can you please list the “bypassed unmarked certification requirements”. Can you name a few CFRs that the 737 bypassed or are your comment general hyperbole?


There is a "deforming" copy error in your question.


Can you prove that the 737MAX conforms to the same obstacle clearance and single engine out requirements the A320 is certified for?
Same for max fuselage g forces. ( seats today have the higher crash resistance but the fuselage they are attached to not.)



Well, you are the one who said:

"It is still flying because Boeing managed to bypass the majority of upmarked certification requirements."

Instead of answering his challenge to that point, you gave a shuck and jive deflective answer.

So, What exactly are the ""upmarked certification requirements' that Being bypassed?

Why not try to address his point. Is there any particular reason that you did not?
 
Weatherwatcher1
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Re: 737 with new wing, landing gear potential

Thu Jun 24, 2021 1:18 pm

WIederling wrote:
ClipperMonsoon wrote:
hiflyeras wrote:
What it really needs is a wider fuselage in addition so so many other things as you mentioned. As long as Boeing relies on the 707 specs it'll never see success over Airbus.


And what 707 specs might that be, the upper fuselage width?, I guess it goes to show what a fantastic jet was built by Boeing over 64 years ago and still flying..


It is still flying because Boeing managed to bypass the majority of upmarked certification requirements.
It is a banged up 1950 relic with no real concept.
( you see similar in the US small trucks domain. 1930 relics. unsafe at any speed :-)

compare to the Airbus FBW concept that presents a homogeneous flying experience over the type range.
( it is not the FBW alone but the concept of an abstract flying model that all types adhere to ( mostly ))


I believe you are confusing the 707 and 737MAX (or may not understand the differences). The 737 MAX isn’t flying with a bunch of 707 designed parts. There may be a few 727 hydraulic system parts, brackets or fittings that use standard part numbers carried over.

Can you list parts from the 1950s currently on the 737? Please provide a part number example.

Can you list bypassed upmarked certification requirements? Are you implying that the 737 doesn’t meet the same obstacle clearance requirements as the A320?

I’d be interested in seeing actual examples of the majority of CFRs bypassed otherwise it appears that your statement is made up to imply the 737 is a relic of the past that shouldn’t be flying let alone have upgrades to the gear and wing be considered
 
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SEPilot
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Re: 737 with new wing, landing gear potential

Sat Jun 26, 2021 4:45 pm

The problems with a clean sheet design are 1) the massive amount of money required and 2) the disruption to production while Boeing workers learn to build it and then ramp production up to the 50+ per month that will be needed to meet demand. It is very easy for armchair CEOs to say that the 737 has reached the end of the road, but they do not have to face the board and say we are going to spend $15 billion, lose 2 years worth of production, and then end up with a plane offering only a 3-5% improvement in operating costs while costing much more. I am looking for a way to minimize the investment, keep as much as possible the same and maximize the improvement. The MAX, while an improvement in fuel consumption over the NG, is clearly inferior to the A320NEO but not by a big enough margin to justify a clean sheet replacement. Boeing should have done the new wing and landing gear with the MAX, but maybe they felt they couldn’t afford the time. So they had it grounded for nearly two years instead.
 
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NameOmitted
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Re: 737 with new wing, landing gear potential

Sat Jun 26, 2021 5:59 pm

SEPilot wrote:
The problems with a clean sheet design are ...

You make good points. As a counterpoint, the MAX is still very young, and ether is a genuine possibility that when it's time for a refresh Boeing will have access to the transonic truss-braced wing and open fan engine. Together, they could be the disruptive technology that provides benefits worth $15 billion and two years of minimal production.

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