Boeing Launches 737 New Engine Family

Eye brow windows are now gone as well on production aircraft with a retrofit mod to fit blanks to Classics as well. 2 out of 3 now! 🙂

They got rid of the shroud on the NG.

I didn’t know that, thanks.
I don’t have anything to do with the NG’s but I’ve been working the -200’s and -3/4/500’s for years. When ever they say they are going to “Warm over” the 737 I think of the poor bits, the APU shroud, eye brow windows and the brake attachment bolts to name a few.
Now you tell me the shroud has gone that’s three of my pet dislikes gone!:D
I always think that the aircraft manufacturers should go down to the shop floor and ask the engineers about the bits that they hate on their previous designs before thay start to design a new aircraft. Every engineer has loads of them.

Rgds Cking

[QUOTE=Amiga500;1795801]

They know fine well propfans are absolutely key to the next generation single aisle, and that any new frame built before that is on a hiding to nothing. (unquote)

I remember reading an article about 20 years ago in Air&Space that Boeing thought that whilst designing the 737-300 and that it might sell a few hundred before the prop-fans came in!!!!!

They got rid of the shroud on the NG.

http://www.newairplane.com/737/737Max/

Looks like the have changed the design of section 48, and got rid of that awful APU inlet.

Let’s hope they have sorted out the whole of the APU bay and got rid of the bl***y shroud! I had to top the oil up on one last night, so the shroud is top of my hate list at the moment!:mad:

Rgds Cking

As an side, years ago I remember reading that Boeing gave Ilyushin data on how to hand engines underwings for their IL-96. In return the USSR gave Boeing sokme data on how to machine titanium. Anyone else remember that or am I mistaken ?

Interesting… I searched Flight’s online archive but drew a blank, however you might just be onto something there. I’ve frequently wondered about the remarkable (if superficial) resemblance between the PS-90A nacelle and some aspects of NASA’s Energy Efficient Engine (E³) programme from the late 1970s. The time frame fits perfectly as well.

Do you have any more specific memory of where you heard about this exchange? Are you positive that you are not confusing it with the more well-known talks about exporting RB.211 or CF6 turbofans to the USSR around the same time? Thanks in advance!

Boeing gets some state tax brakes…and some R&D from NASA. Do they compare? Depends on who you ask.

Between that, cross-pollination from lavishly funded military projects and non-accountable black project money, I would be surprised if they don’t at least compare. This is not a question of the 737 in particular either as you imply above, that’s a bit of a deflection on your part.

but to me the top lip of the Nacelle seems to be above the wing leading edge

That in itself doesn’t necessarily matter.

meaning point 2/3 are significantly compromised

No – meaning point 2/3 may be significantly compromised if appropriate steps are not taken to handle the potential problem.

Also as the cord line of the engine gets closer to the wing cord achiving zeroshock-induced BL separation becomes somewhere between very difficult and impossible.

Sorry – but what?

I assume you are talking about the reduced pylon length between wing and nacelle?

‘Back in the day’ it was assumed that the gap would have to be of the order of 1 nacelle diameter. That quickly reduced to 0.5 diameters.

Recent times, its under 0.1 without any significant problems. NASA have previously done work on much closer integration (late 90s if memory serves – check the ntrs). You need to consider lateral curvature of the pylon to control this, but its well understood and not a big deal for Airbus/Boeing.

A supercritical aerofoil pressure surface may, indeed usually will, have a weak shock on its lower surface, but this is usually 3/4 or later chord length. Due to the weak nature of this shockwave, there is no BL separation on the pressure surface of any well designed (i.e. any Boeing/Airbus) wing.

The nacelle bypass shroud has long since terminated by that point, and your into the flow downstream of the nozzle, which is underexpanded anyway with a very complex shock structure. But this is normally separate from the small transonic pocket on the wing pressure surface.

Just 18 months ago Boeing were talking about the 737 being at the end of it possible development due to problems around the integration of a larger fan engine.

It is the same PR bullsh!tters that tried to disparage the NEO now trying to maximise everything to do with the 737 re-engine. They are best treated without outright contempt, or, at least completely ignored.

I’m fairly certain the engineers would have completely backed a re-engine. They know fine well propfans are absolutely key to the next generation single aisle, and that any new frame built before that is on a hiding to nothing. But that doesn’t stop bullsh!tters like Albaugh coming out with complete p!sh – he’s a project manager – never designed a f**king aircraft part or system in his life.

Agree Arthur. I have no doubt that Southwest is driving the bus on the stupid cockpit to supposedly save pilot re-training costs. Darn them! How can one customer ruin a design for the whole industry?

What a shame the flight deck isn’t going to change. Boeing have an opportunity to bring the 737 cockpit into the 1980s 🙂 but it seems they aren’t going to take it. The overhead panel and centre pedestal are ergonomic nightmares from nearly 50 years ago.

I’ve used both A320 and 737 flightdecks and the Airbus is streets ahead in terms of almost every parameter you can think of.

Turbulent flow separation?

CL max is not important for cruise. L/D is.

Also, with the nacelle shroud lowering as it approaches the wing leading edge, the turbulent boundary layer – which remains attached* – this turbulent sheet passes below the wing.

Simplified: the main aspects of nacelle-pylon integration are:

• minimising excrescence drag from the pylon-wing interface
• ensuring the design stagnation point (line) on the wing is unaffected by the presence of the nacelle
• minimise the change in pressure distribution on the wing pressure surface due to the presence of the nacelle (or, if possible, modify it advantageously)

*There is no shock-induced BL separation on any competently designed nacelle.

Cruise L/D will be evitable lost if a section of the wing is exposed to poor Nacelle integration QED.

I agree with your Nacelle/Wing optimisation objectives, but to me the top lip of the Nacelle seems to be above the wing leading edge meaning point 2/3 are significantly compromised (the 787 & 737 pictures are at different viewing angles but you can just about see it…….). As the impact is on area the loss of wing efficiency for the impacted section will be exponential.

Also as the cord line of the engine gets closer to the wing cord achiving zeroshock-induced BL separation becomes somewhere between very difficult and impossible.

Just 18 months ago Boeing were talking about the 737 being at the end of it possible development due to problems around the integration of a larger fan engine. Now, under pressure from NEO sales, the same guys that brought you the 787 programme disaster have decided that its now all possible again. As I said before I was expecting a longer MLG with a shortening mech.

In regards of the cockpit, I remember reading that the airlines asked Boeing not to change it so I believe it may be the same. Although there could be some slight differences I suppose?

Edit: Just found the site from where I read the above.

“Albaugh also said Boeing plans no changes to the 737 Max’s flight deck: “The one thing we do want to make sure we have with this airplane is compatibility with the NG, compatibility with airplanes we’ve already delivered. What customers have told us is don’t touch the cockpit, and our plans are not to do that.”

http://www.flightglobal.com/articles/2011/08/31/361440/boeing-aims-to-minimise-737-max-changes.html

Amiga – Please advise, for a cruise mach number, the percentage cord for an Engine Nacelle where flow transition occurs which leads to turbulent flow separation.

Turbulent flow separation?

Are you getting confused between boundary layer transition and separation. There is no separation on the nacelle, however there is transition.

Off the top of my head: On a conventional nacelle, in cruise, transition would be expected to occur before 5% chord length. The DLR did quite a bit of work on laminar nacelles in the early to mid 90s – with some patchy results, good BL flow over 50% chord length on some bits of the nacelle, and much less impressive on others.

Also please advise the CL max that can be expected for a supercritical aerofoil within a separated turbulent air flow.

Erm? (on the separated flow)

Assuming you mean turbulent boundary layer.

CL max is not important for cruise. L/D is.

Also, with the nacelle shroud lowering as it approaches the wing leading edge, the turbulent boundary layer – which remains attached* – this turbulent sheet passes below the wing.

Simplified: the main aspects of nacelle-pylon integration are:

*There is no shock-induced BL separation on any competently designed nacelle.

You don’t need separation of the frontal projection of the nacelle/wing to guarantee lift.

[/IMG]

Amiga – Please advise, for a cruise mach number, the percentage cord for an Engine Nacelle where flow transition occurs which leads to turbulent flow separation.

Also please advise the CL max that can be expected for a supercritical aerofoil within a separated turbulent air flow.

To make such a bold statement as this you should be able to answer these questions.

As for the twaddle about Boeing being the only manf to “hire people to make aeroplanes” it really show zero understanding of the industry.

As for US subsidisation of Boeing;- The podded jet engine was developed for the Boeing B47 paid for by DoD then gifted to its civil business, the CFRP fuselage was developed for the Boeing Osprey paid for by DoD then gifted to its civil business and there are numerous other small examples of gifting;- a typical unseen example is the analysis package used for Birdstrike Cert known as “Dyna3d” originally paid for DoD to model underground nuclear tests.

Upon investigation at Boeing’s request, the WTO decided there was no case to answer.

With regard to the aerodynamic comments, does it seem realistic to be making assessments based upon artist renderings? Shouldn’t one wait until they see something a little more definitive?

True. I just quickly want to quash the absurd notion that Boeing would actually design an aircraft where 10% of the wing is not working!

I looked at the Boeing website and did not see any cockpit renderings. I’m hoping that Boeing ditches the 1968 overhead panel that Southwest mandated for the NG, and also installs a modern EICAS/ECAM type system.

I think they are strongly insisting on keeping the cockpit common to eradicate any (or vastly reduce) retraining of glorified button pushers/pilots.

Boeing is a company that hires people to build airplanes, Airbus is a political consortium that builds airplanes so they can hire people.

Now, now, behave.

I guess Hawker-Siddeley, English Electric, Vickers-Armstrong, Bristol, De Havilland, Sud Aviation, Aerospatiale and Breguet (to name a few) had no history of building aeroplanes prior to their combining? :confused:

Using the same yardstick; would that mean that the combination of Lockheed, General Dynamics and Martin into Lockheed-Martin mean they are a political consortium that builds aeroplanes so they can hire people?

Or Northrop and Grumman?

Or McAir and Boeing?

Due to the smaller size of each European country relative to the US, the consolidation process of indigenous companies started much earlier – which maybe is what makes it harder for… ‘an outsider’ (for lack of a better term) to see the lineage. The combining of the respective companies into Airbus was largely driven by the private companies need to lump together to survive, not by the politicians.

[Oh, and for the avoidance of doubt – while I know there are some incredibly smart people at Airbus – I also know there are a large number of inept bstards there too – particularly within their procurement branch. There is a culture of ‘zero responsibility’ within the company as well as a culture of ‘managers’ and procurement zombies leading chief engineers, which may or may not be different at Boeing.]

With regard to the aerodynamic comments, does it seem realistic to be making assessments based upon artist renderings? Shouldn’t one wait until they see something a little more definitive?

I looked at the Boeing website and did not see any cockpit renderings. I’m hoping that Boeing ditches the 1968 overhead panel that Southwest mandated for the NG, and also installs a modern EICAS/ECAM type system.

Boeing is a company that hires people to build airplanes, Airbus is a political consortium that builds airplanes so they can hire people.

Dear oh, oh dear what a mess the wing to engine aero integration is……about 10-15% of the span is now generating no lift, only drag (compare to the competitors where a clear separation of allows the wing to earn its keep).

You don’t need separation of the frontal projection of the nacelle/wing to guarantee lift.

As long as the nacelle recedes in diameter prior to the leading edge of the wing, and allows sufficient clearance around that point, then lift can still be generated virtually uninhibited.

As an example, Boeing have a similar pylon arrangement on the 787. They did not compromise the aerodynamic performance of that any more than is necessary.

B787

and: here (bit big)

B737

And as for a job creation scheme, please remind me how much funding does Boeing gets from US black projects?.

My comments were general in nature given the amount of funding aireframe companies (especially start-ups) get from their nations. I didn’t mention any names. Why do you assume I meant Airbus?
Is there something you want to confess? 🙂

Of yeah, the 787 is supercruise stealth, almost forgot. 🙂
Please feel free to explain what “black” technology is finding its way into 737s…which you seem to think are more than ancient (not that I’d totally disagree).

Since the Boeing came out with jetliners (remember the prototype was privately funded, BTW) fback inthe 50s and Airbus used the same basic (underwing pods) configuration, didnt Airbus get some basic R&D or proof of concept experience from Boeing? :diablo::D:diablo:

As an side, years ago I remember reading that Boeing gave Ilyushin data on how to hand engines underwings for their IL-96. In return the USSR gave Boeing sokme data on how to machine titanium. Anyone else remember that or am I mistaken ?

Remember, a lot of basic R&D is funded by NASA and universities…which is shared. Likewise I’m sure Farnborough and French data eventually goes industry-wide. But there is no denying that Airbus and EADS do get sweethart financing (witness the A380 loans) from state banks and government investors (like the German provinces).
Boeing gets some state tax brakes…and some R&D from NASA. Do they compare? Depends on who you ask.

Longshot
Yes it really is “that simple” and no amount of computer analysis will fix it. You need an aerofoil section to produce lift.

J Boyle
“As I pointed out above, there are good cases to be made for NOT doing a new aircraft. Aside from costs, one being why put new-old technology engines on an all-new airframe?”

But doggedly sticking with a throw back to the days of the turbojet Pax A/C of some 50 years ago is a bit rich don’t you think.(i.e the poor ground clearance which really messes up the integration of a modern high bypass ratio turbofan).
I was really expecting a longer MLG and/or one with a shortening mechanism to at least exploit some of the potential saving.

And as for a job creation scheme, please remind me how much funding does Boeing gets from US black projects? ……all untraceable of course as to where’s its actually spent ……..lets just leave it there shall we.

It’s rash to presume having the engine directly mounted to the wing wipes out the lift in that area…I doubt if it’s that simple and they’ll do a lot of work refining the aerodynamics round there

Still I guess its an inevitable consequence of Boeing using some of the engine performance improvement to save themselves from spending money on the cert cost of a new airframe……albeit at the expense of their customer’s bottom line.

Thanks for that objective tirade. :rolleyes:

Your line: “At the expense of their customer’s botton line” is rich.
Who do you think would pay for the extra R&D? The airframe fairey?
The customers would have to pay for it with higher cairframe prices.
Unlike some outfits, Boeing is not a make-jobs charity and has to answer to shareholders who expect a profit.

As I pointed out above, there are good cases to be made for NOT doing a new aircraft. Aside from costs, one being why put new-old technology engines on an all-new airframe?

After all, its main competitor isn’t doing one yet and even to Boeing $6 billion is a lot of money.

Let’s see what the Canadians, Brazillians and Chinese come up with in the segment.