Primarily for general aviation discussion, but other aviation topics are also welcome.
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#1687024
Paul_Sengupta wrote:Considering Boeing developed the 757, what was Boeing's thinking regarding the decision on keeping the 737 and getting rid of the 757 and not using the 757 as the basis for a family of aircraft?


Bump.

Would love to see an answer to this and also whether there would have been viability (and value) in restarting 757 production.

Was the 757 a different fuselage design with the 737 being derived from the 707 (as with 727)?
#1687035
https://en.wikipedia.org/wiki/Boeing_757

The fuselage cross-section, whose upper lobe was common to the 707 and 737, was the only major structural feature to be retained from the 727. This was mainly to reduce drag, and while a wider fuselage had been considered, Boeing's market research found low cargo capacity needs and reduced passenger preference for wide-body aircraft on short-haul routes.
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By Dominie
#1687239
eltonioni wrote:
Does that stripped out B737 still do the LCY - NYC route?
Edit: Just checked, it was an A319 with a fuel stop at Shannon. :roll:

No it wasn't, it was an A318! 8) :lol:
BA had two and have sold one which presumably is still doing that route.
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By eltonioni
#1687340
Dominie wrote:
eltonioni wrote:
Does that stripped out B737 still do the LCY - NYC route?
Edit: Just checked, it was an A319 with a fuel stop at Shannon. :roll:

No it wasn't, it was an A318! 8) :lol:
BA had two and have sold one which presumably is still doing that route.

Don't confuse me, I struggle to tell an Airbus from a Boeing unless it has two decks or a hump :lol: :thumleft:
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By eltonioni
#1688066
There's a report beginning to do the rounds that Boeing have made a claim in the competitions case against Bombardier that the B737 Max isn't for use at hot/high airports. It seemed to be a commercial point to preserve sales of the smaller / lighter versions which perform better in hot/high conditions and are presumably competition with Bombardier a/c.

Surely they can't be so bonkers to have made that statement and then sell anything, to anyone, no questions asked. It could be their Ratner moment for the business.

https://www.bloomberg.com/news/articles ... n-airports
By Big Stu
#1689367
eltonioni wrote:
Dominie wrote:
eltonioni wrote:
Does that stripped out B737 still do the LCY - NYC route?
Edit: Just checked, it was an A319 with a fuel stop at Shannon. :roll:

No it wasn't, it was an A318! 8) :lol:
BA had two and have sold one which presumably is still doing that route.

Don't confuse me, I struggle to tell an Airbus from a Boeing unless it has two decks or a hump :lol: :thumleft:


Boeing strobes go flash—flash—flash

Airbus go flash-flash—flash-flash—flash-flash

:D
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By PaulB
#1689368
Big Stu wrote:Boeing strobes go flash—flash—flash

Airbus go flash-flash—flash-flash—flash-flash


I’m far from an expert but I’ve noticed that Dreamliner strobes go flaaash..... flaaash.... - definitely “dahs” rather than “dits”.
#1689377
joe-fbs wrote:Another new article is linked below. Everything I have read about these crashes tells me that they got the FHA and SSA wrong. Also FAR 25.1309 does not forbid a single point cause for a Catastrophic scenario while CS-25.1309 does.

https://spectrum.ieee.org/aerospace/avi ... -developer


That’s a great article.
terryws liked this
#1689379
Good article but some factual inaccuracies.

Let’s review what the MCAS does: It pushes the nose of the plane down when the system thinks the plane might exceed its angle-of-attack limits; it does so to avoid an aerodynamic stall. Boeing put MCAS into the 737 Max because the larger engines and their placement make a stall more likely in a 737 Max than in previous 737 models.

When MCAS senses that the angle of attack is too high, it commands the aircraft’s trim system (the system that makes the plane go up or down) to lower the nose. It also does something else: It pushes the pilot’s control columns (the things the pilots pull or push on to raise or lower the aircraft’s nose) downward.


The system isn't designed around stall prevention or indeed AOA limits. It is there because the lift generated by the relocated engines reduces static stability when at relatively high AOAs. In other words, without MCAS the pull-back-on-stick force required from a pilot to raise the nose reduces as you increase AOA; this is an unsatisfactory feature as far as certification is concerned and contrary to the effect that one normally experiences when pitching-up. Boeing got around this by developing MCAS which intentionally puts the stabilator in a nose down out-of-trim position when it thinks you are at a high AOA. (Have a go when flying sometime, maintain straight and level and then trim nose down - you'll have to apply increasing amounts of back pressure to maintain attitude as you add nose down trim).

The problem is the result of an aerodynamic issue which is 'fixed' by intentionally taking the aircraft out of trim. An unfortunate side-effect is that MCAS is a bit of a simple soul and it will continue to want to trim nose down as long as it is getting high AOA data. Somewhere along the line, the nose-down trim on the stabilator will require a force greater than the pilot can apply in trying to pull the stick back. Indeed, there is probably a point whereby the effect of full elevator (if you could ever get there) would not be enough to counter nose down stabilator.

From a safety manager's perspective, the development and introduction of MCAS will in the future provide excellent case studies in how NOT to design an aircraft system.
johnm liked this
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