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chrisg

Problems with the 737MAX ?

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The 737 Max8 was created with trying avoid FAA re certification tests in mind to cut costs and time to get to production because they got in a panic when the A320 came out.

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Well,

 

The 320 is a family of aircraft that Boeing have been in competition with for years J. Whilst Airbus have jiggled around and produced different versions, the 319 for example, they are nonetheless all of the 320 family and through Airbus' initiative of fbw all of the aircraft do have a real high degree of commonality so moving between members of the family has been easy.

 

In reality it has never been quite so simple for Boeing through the tyranny of installed base, the 737 is a much older aircraft but Boeing have kept on and kept on upgrading it including moving from analogue to glass cockpit. That alone did so I discovered require a degree of re-training although not much in the way of re-certification. I don't pretend to know all the ins and outs of the FAA certification process but  there is a division between commonality of airframe and training for fairly obvious reasons.

 

Boeing fought hard to keep Airbus out of their core market, the U.S. but lost out quite strongly when American began buying 320s in large numbers - the airline particularly liked the flexibility of the various models to cover its diverse route map.

 

Overall the two companies have been neck-and-neck for years in the space that their competing products address but it would be fair to say that Boeing have been on the back-foot for a great deal of the time through not having the luxury of a clean sheep of paper that Airbus did. Boeing has stayed in the race mostly through the inertia of incumbent airlines staying with the brand and crew familiarity. The latter has long been moot though with Airbus now well entrenched in the market.

 

With hindsight Boeing probably should have bitten the bullet and moved to develop a new replacement for the 737 a long time back but instead they have kept on trying to wring more life out of the design.

 

It's ironic really that the 737 has lasted for so long in the Boeing line up when the 727,757, 767, even the 717, although that was really just a warmed over DC-9 post the merger, have come and gone. With the 747 now at or very close to EOL Boeing  are down to the 777 family and the 787 Dreamliner apart from the long, long lived 737.

 

It really is time for a new model, there is too big a gap between the 737 and the Dreamliner. The 797 might be it but that aircraft remains a bit of a mystery. Boeing had expected the MAX range to fill the gap at least for a while and the massive order book certainly supported that belief. Whether the MAX can survive the very bad press of the past few months will have to remain to be seen.

 

Cheers

 

 

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I don't blame the engineers or designers, they were put in this situation by the upper management who made these decisions. They wanted product that could be pushed out to production quick bypassing FAA time and money consuming checks. They got it, it had an Achilles heel but I suspect the people who designed the plane didn't have a real say with that MCAS fiasco.

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Totally agree, it was all driven by upper management.

 

Unless, and I doubt it, there is something hidden away about there having been any issues with MCAS during test flying then the engineers, and test pilots, would have signed the aircraft off without issue.

 

There almost certainly however was a degree of complacency involved both within Boeing and within the FAA.

 

Boeing had released multiple models of the 737 at a rather furious pace as they reacted to the Airbus initiatives, all without incident. Humans are humans, they expected nothing to go wrong, business as usual, so it was. Aircraft however have in the past, and probably will in the future, a disquieting tendency to have issues crop up down the track that were completely missed during test and development. The DC-10 was probably one of the worst but certainly not a sole example.

 

Upon reflection it might have struck people that the MAX is not simply another stretch of the venerable 737, by changing the engines and thus having to rethink their location to accommodate the long completely unnecessary low stance of the aircraft (designed that way before air bridges became the norm) several critical parameters were changed. That should really have been enough to go deeper into the certification process but the FAA trusted Boeing, who were likely not being duplicitous, simply under pressure to get the design out the door and begin filling orders.

 

Cheers

 

 

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Posted (edited)

Boeing need to change the MCAS so it can be disabled in case the sensors are bad.

The FAA have a lot of blood on their hands after past failures with other manufacturers anyway.

Edited by Jeruselem

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Hmm,

 

MCAS needs proper redundancy, AND the ability to easily disconnect it if required. I'd be more relaxed about it if the MAX were demonstrated to be safely controllable by a mundane pilot (if you can find one!! 🙂 ) with MCAS totally out of the loop.

 

That then of course begs the question why is it needed in the first place.

 

FAA is not perfect, nothing is, but it is not a very good reflection upon the industry at all that they have indeed been seen to be somewhat tardy in enforcing tighter air safety regulations even after they have passed into law.

 

It's been a subtle change that has taken decades, the UK's CAA was long regarded as the premier body in air safety but as the UK's aviation industry has faded so too has the influence of the CAA.

 

Cheers

 

 

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Yeah...

 

Definitely not a good look, especially being given 10 days to replace them on a grounded fleet - not sure of the logic of that particularly when Boeing have given no updates on looking for return to service.

 

It is going to take Boeing a damned long time to repair the brand damage and the longer the grounding goes on the longer it will take.

 

Cheers

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Geez what other faults have Boeing been hiding from us ...

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I guess the planes aren't flying so they can go fix this issue ...

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...Explains the 10 day requirement if NGs are also affected, those aren't grounded.

 

Probably not terribly serious , slats are a "nice to have" most of the time rather than essential, they just let you fly slower.

 

It does depends what the failure potential is though, jamming would be one thing mechanical failure another.

 

Cheers

 

 

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20 hours ago, Jeruselem said:

Then you got the "optional" warning lights ... if you paid for it ... it was a standard item but it was a "premium" item.

Would be odd for them to believe that as the warning light can only operate if there are two AoA sensors and I thought the standard fit out only had one AoA?

Does point more and more to Boeing have some major in house systemic failures though.

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It's murky in that regard Ali, as rather a lot of it is.

 

It seems there is indeed only one AoA sensor in the loop, at a time... If I read the spec.correctly, and it is difficult to believe sometimes what I'm reading there are two sensors but in the bare bones configuration only one is in the MCAS circuit. If you pay more you get the warning light - which seems to suggest they then hook up both sensors but only use one at a time unless one fails. Just what the failure rule is the spec does not say.

 

We discussed a few pages back that economically the wiring for both would just be there, connect if required, but really, talk about nickel and diming...

 

Potentially it goes further, to respond correctly to a system with sensor comparison would require a different software law to a single sensor system. Or perhaps no one thought of that and the single sensor system therefore became confused easily...

 

There is a very disquieting feeling of decadence going on here. I do not even pretend to think I know what the spec. is actually saying, because I don't. I'm not convinced the engineer who wrote it did either.

 

Cheers

 

 

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Yeah...

 

It's an interesting move being they buy for a diverse number of airlines as a holding group.

 

I will bet my bottom dollar that they received a massive discount to make this intent to purchase announcement, quite possibly below cost, after all Boeing still has inventory building up and nowhere to put them.

 

Cheers

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