B737MAX Grounded Worldwide Q1 2019

scbriml · Fri Mar 22, 2019 11:08 am

Waterbomber2 wrote:
AF447 couldn't recover from an airspeed disagree situation at cruise altitude.

AF447 was completely recoverable and shouldn't have even got into a situation where recovery was required. Pilots regularly handle loss of IAS without incident. Sadly, the crew of AF447 were woefully inadequate when it mattered most.

SheikhDjibouti · Fri Mar 22, 2019 11:15 am

mjoelnir wrote:
Boeing will not be able to abandon the MAX. The 737 has been and is the main cash cow at Boeing. The 737MAX grounding will be much more serious for Boeing than the 787 grounding. Positive cash flow will come to a stop. The cash from the 787 will perhaps way up against cash expenditure for the finalizing of the development and ramp up of the 777X. Boeing will burn cash in the near future. They will cancel the 797. There is no time for a clean sheet replacement of the 737MAX.

Boeing will redesign the 737MAX, it will become a safe frame and they will keep delivering it, perhaps not as many as were expected. The aviation safety agencies outside the USA will see about, that Boeing will not cut corners again on safety. The main question will be how long it will take Boeing to do this and how much money Boeing will burn meanwhile.

If only Boeing had bought the C-series from Bombardier, instead of trying to litigate against it. Instead they handed it over to Airbus, on a plate.

On the other hand, 18 months ago, they would have bought Bombardier, and then killed the C-series dead. All hail the MAX !

What an opportunity missed. :rotfl:

Amiga500 · Fri Mar 22, 2019 11:18 am

seahawk wrote:
First there is nothing fundamentally wrong with the MAX. Add an AoA disagree warning and correct the MCAS software and it is just fine. Secondly any competition still lacks the economy of scales advantage and product support to compete with the 2 big players.

The existence of MCAS would indicate there likely is something fundamentally wrong with the MAX.

If the aircraft has an aero centre that moves forward signficantly at high AoA to the point that it becomes unable to pitch down to recover from that AoA, or worse, prevent that AoA further increasing into a stall - then that is a pretty fundamental problem.

The correct answer would have been a resize of elevators (and horizontal stabiliser too). But if the aero centre is moving significantly it will need the elevators to be oversized, the actuators upsized and the pilots to get a new type certificate as the control responses would be very different.

That will take time and cost $$$.

seahawk · Fri Mar 22, 2019 11:20 am

Amiga500 wrote:
seahawk wrote:
First there is nothing fundamentally wrong with the MAX. Add an AoA disagree warning and correct the MCAS software and it is just fine. Secondly any competition still lacks the economy of scales advantage and product support to compete with the 2 big players.

The existence of MCAS would indicate there likely is something fundamentally wrong with the MAX.

If the aircraft has an aero centre that moves forward signficantly at high AoA to the point that it becomes unable to pitch down to recover from that AoA, or worse, prevent that AoA further increasing into a stall - then that is a pretty fundamental problem.

The correct answer would have been a resize of elevators (and horizontal stabiliser too). But if the aero centre is moving significantly it will need the elevators to be oversized, the actuators upsized and the pilots to get a new type certificate as the control responses would be very different.

That will take time and cost $$$.

I see it as an envelope protection system common on modern airliners.

Interested · Fri Mar 22, 2019 11:24 am

Amiga500 wrote:
crimsonchin wrote:
The MAX will be fine if only because Airbus cannot handle those orders.

Agreed.

Boeing are *very* lucky that neither of the MC-21 or C919 are certified and flying passengers yet - or that Bombardier didn't start with a CS300 then move to a CS500 (instead they erroneously [IMO] did CS100 first).

The duopoly will still exist after the dust settles - if any of the above had happened then it would likely be broken.

To the above posts suggesting Boeing will be fine

I guess it depends what you mean by fine long term. Short term it's probably going to get worse before it gets better though

Best case scenario here is an organisation losing 100s of billions of dollars one way or another.

Not sure how much they can afford to lose. Could they afford to lose a trillion dollars? However, one way or another I'm sure the business will somehow survive and prosper again in the future as it's simply too big and important to lose outright

Airbus will certainly be rubbing their hands in the meantime

I also envisage 12 months plus from now it will be operating with an entirely new management structure

So yes the brand will be fine

The profits/losses will be absolutely horrendous and you won't recognise the management

This isn't a minor blip. It's going to to cost a huge amount to sort this and it's going to taken management casualties in key roles to restore any trust

Boeing will survive but I imagine this will prove to be the biggest crisis and certainly by far the most expensive they've ever had to deal with

scbriml · Fri Mar 22, 2019 11:24 am

Amiga500 wrote:
seahawk wrote:
First there is nothing fundamentally wrong with the MAX. Add an AoA disagree warning and correct the MCAS software and it is just fine. Secondly any competition still lacks the economy of scales advantage and product support to compete with the 2 big players.

The existence of MCAS would indicate there likely is something fundamentally wrong with the MAX.

It may be that there is something fundamentally wrong with the MAX if Bjorn Fehrm is correct.

https://leehamnews.com/2019/03/22/bjorn ... sh-part-2/

Blowback means the elevator is gradually blown back to lower and lower elevation angles by the pressure of the air as the speed increases. The hydraulic actuators can’t overcome the force of the air and gradually back down if the force of the air grows too strong.

If a blowback problem is confirmed for the 737 at the speeds and altitudes flown, this is what happened at the end of the JT610 flight and probably ET302.

art · Fri Mar 22, 2019 11:28 am

crimsonchin wrote:
This isn't going to trigger a mass MAX cancellation. Maybe from ET or Lion Air if they feel Boeing didn't handle the incident better. But most likely any other cancellation will be from airlines who were already considering cancelling anyways due to other unrelated reason. The MAX will be fine if only because Airbus cannot handle those orders.

Let's not forget that Airbus is still making A320CEO's and Boeing still making 737NG's. You don't have to buy a MAX if you want a 737.

I go along with another poster (can't see while I'm writing) who more or less said that the MAX brand is cursed in the consumer's mind and a new name is needed. I think Boeing made a big mistake in keeping quiet about the type's instability issue and the fact that MCAS was there to guard against any repercussions. They should have squared up to this, ensured that it was covered in the operating manual and ensured that recovery from incorrect/conflicting AoA data feeds or MCAS malfunction was fully covered in training.

When the Lion Air MAX went down, Boeing should - as a minimum - have advised airlines to ground the type until crews were fully conversant with steps to take in case of suspected MCAS malfunction. Had they done so, chances are that the crew flying the Ethiopian MAX would not have crashed. .After the Ethioipian crash what was Boeing's response? To maintain that the MAX was safe to fly and should not be grounded. It is reported that attempts were made to persuade the President of the United States that the type should not be grounded.

I don't doubt that Boeing can come up with a certifiable fix to MCAS, which it occurs to me is in itself a fix to a built-in design problem (engines not being located where they should be). So I expect Boeing will be able to fix the defective fix to the defective design.

I suspect that the confidence of the travelling public in the MAX has been lost, given all the revelations that are emerging and investigations being opened. No idea where Boeing goes from here in terms of the MAX but I think the brand is toast - poisoned toast.

asdf · Fri Mar 22, 2019 11:44 am

art wrote:
...When the Lion Air MAX went down, Boeing should - as a minimum - have advised airlines to ground the type until crews were fully conversant with steps to take in case of suspected MCAS malfunction. Had they done so, chances are that the crew flying the Ethiopian MAX would not have crashed. ...

exactly THAT is the point

It is a matter of opinion if the management should try to find and use all abbreviations in order to achieve the best possible result in terms of salesmanship.

but at the latest when it has turned out that one of the abbreviations does not work and it has come to a loss everything must be done to avert further damage

this has not been the case here.
one tried to hide.

and more people had to die

this is unacceptable

Amiga500 · Fri Mar 22, 2019 11:52 am

seahawk wrote:
I see it as an envelope protection system common on modern airliners.

Not the same.

There are required flight envelopes in FAR25.

There are parts within FAR25 for stick pushers - 25.103(a) and 25.103(d) - the complete section 25.103 deals with stall speeds.

MCAS is not operating like a stick pusher - a stick pusher by definition works on the elevators so the pilot gets feedback on the control column from the push.

The A320 has flight envelope protections - but these stop the aircraft exceeding the envelope by stopping a dangerous control input from the pilot.

MCAS is a discrete nudge (the size of the nudge being a function of Mach number) irrespective of what the pilot continues to do - they can still pull full back on elevators and MCAS will pay no heed to it.

Boeing may be able to make MCAS a conventional stick pusher - but they might struggle to make Vsr as a result - hence why MCAS is hidden out of sight.

SheikhDjibouti · Fri Mar 22, 2019 11:54 am

seahawk wrote:
Amiga500 wrote:
The existence of MCAS would indicate there likely is something fundamentally wrong with the MAX.

If the aircraft has an aero centre that moves forward signficantly at high AoA to the point that it becomes unable to pitch down to recover from that AoA, or worse, prevent that AoA further increasing into a stall - then that is a pretty fundamental problem.

I see it as an envelope protection system common on modern airliners.

Bingo - we have a winner!
It is a common feature on most MODERN airliners.
Modern airliners with FBW and other little tricks, all engineered into them from the get-go, and fully certificated for what they actually are.

And then we have the 737.....

(Sorry - you walked right into that one.) :lol:

Andy33 · Fri Mar 22, 2019 12:04 pm

art wrote:
Let's not forget that Airbus is still making A320CEO's and Boeing still making 737NG's. You don't have to buy a MAX if you want a 737.

.

Boeing is still making 737NGs, but only just. The order book has been run right down and the last few passenger versions should all be built by the end of next month. There's no suggestion that new orders have been a possibility for quite a while. However the military plane based on the NG will still be in production for ages yet. What would be interesting to find out is what components for the MAX are identical to the NG and are therefore still very much in production and indeed can be taken from MAX production stock, and what proportion would requiire new production runs by suppliers. Of course ramping NG production back up is of only limited help to airlines who have ordered MAX versions that have no NG equivalent, most obviously the MAX10 but also the 200pax version of the MAX8

Elshad · Fri Mar 22, 2019 12:20 pm

IMHO the FAA (if not corrupted) and EASA etc. should refuse to certify the MAX until major structural changes are made to address the instability, and should not accept software patches. Even if it means the MAX having to be certified on a different certificate than the NG.

Aviation737 · Fri Mar 22, 2019 12:39 pm

namezero111111 wrote:
dampfnudel wrote:
I wouldn’t be surprised if Lion Air is next to cancel their MAX order. I’m sure Boeing is crossing their fingers right about now that the Chinese carriers don’t get any ideas.

They and others should. The 737MAX is unsafe and never will be safe. It is aerodynamically fatally flawed and only got into the air through a corrupted certification process.. Everyone knows it, time to face the music. Time to cut the losses and start over, Boeing.

What do you mean aerodynamically flawed? Can you explain why it will never be safe? If you meant how the aircraft tends to tilts upward due to its more powerful engine and its placement, wouldn't trim solve this problem? Not to mention, the crash is most likely not even due to its aerodynamics but the MCAS which activated at the wrong time and the wrong place.

Aviation737 · Fri Mar 22, 2019 12:59 pm

Carlos01 wrote:
dampfnudel wrote:
I wouldn’t be surprised if Lion Air is next to cancel their MAX order. I’m sure Boeing is crossing their fingers right about now that the Chinese carriers don’t get any ideas.

[First of all they have to rename the plane. Anything with "MAX" -attached to it will more or less equal to "death" in the eyes of the consumers. The Chinese are no different, actually they are even very superstitious, so it's just a matter of time before the cancellations start rolling in.

Then completely another question will be, is the plane even possible to fix? It could well be that before all authorities are happy with it, such major structural changes are required, that it more or less voids the whole business case, and they just have to go with a clean-sheet.

And since we are in the grounding-thread, Boeing would be so much better off in case they would have grounded the MAX-fleet immediately after the first crash. They could have fixed it in peace and quiet, and probably gotten away with the whole thing. But now due to their greed, the shite hit the fan big time, and they will pay a price so high that even the whole company could go bust. Somebody could ask the CEO, how does he himself think he managed the situation, all good?

I bet people would completely forget about this in 1 or 2 years. I mean if half the world's future narrowbody fleet in the future being the MAX, it would be pretty difficult to keep avoiding it in the future. If Boeing really goes for a new clean-sheet design they will be really shooting themselves in the foot. A new design would take at least years for it to roll out of the production lines and they basically won't have any aircraft to compete against the NEOs. Not to mention, it would also be a nightmare for airlines if Boeing stops production on the MAX since they basically won't have any next-gen aircraft to compete with their competitors that have newer aircraft. They basically can't turn to any other manufacturers to provide them with a replacement. The MAX is definately here to stay whether you like it or not.

Amiga500 · Fri Mar 22, 2019 1:04 pm

Aviation737 wrote:
What do you mean aerodynamically flawed? Can you explain why it will never be safe? If you meant how the aircraft tends to tilts upward due to its more powerful engine and its placement, wouldn't trim solve this problem?

Your not allowed to retrim per regulations for stall evaluation FAR25.103.

Indeed - the fact that MCAS uses the stabiliser trim function rather than the elevators to correct for impending stall is contravening the regulations.

FlyBitcoin · Fri Mar 22, 2019 1:13 pm

NYT story today about extra warning features being paid options on the MAX: https://www.nytimes.com/2019/03/21/busi ... harge.html

While they act like making features like this optional is unprecedented, it is certainly not in the auto industry. Auto makers now do have optional cost equipment like blind spot detection, lane keep, adaptive cruise, and pedestrian detection for years in many cars. Some build in the hardware but then charge hundreds or thousands just to code in the feature.

Safety as an option is not unheard of in the transportation industry. The question is, do these safety features in cars make a fully attentive, experienced driver any better? Or are they there to potentially save a bad, distracted driver from himself?

Not saying Boeing is in the right for making a "disagree light" optional but it is not entirely unprecedented in the transportation industry to features that some might consider "safety-related" optional as well.

Carlos01 · Fri Mar 22, 2019 1:14 pm

scbriml wrote:
It may be that there is something fundamentally wrong with the MAX if Bjorn Fehrm is correct.

https://leehamnews.com/2019/03/22/bjorn ... sh-part-2/
Blowback means the elevator is gradually blown back to lower and lower elevation angles by the pressure of the air as the speed increases. The hydraulic actuators can’t overcome the force of the air and gradually back down if the force of the air grows too strong.

If a blowback problem is confirmed for the 737 at the speeds and altitudes flown, this is what happened at the end of the JT610 flight and probably ET302.

Holy crap. If this theory is correct, what does it mean for the MAX? And in case the blowback-effect is fuelled by the oversized engines that don't really fit on the plane as they should, would that be the end of it? Meaning could it be that the MAX has seen it's final revenue flight already?

The more we learn about all this, the more it looks like there may indeed be more to this than just a bugfix.

LDRA · Fri Mar 22, 2019 1:20 pm

FlyBitcoin wrote:
NYT story today about extra warning features being paid options on the MAX: https://www.nytimes.com/2019/03/21/busi ... harge.html

While they act like making features like this optional is unprecedented, it is certainly not in the auto industry. Auto makers now do have optional cost equipment like blind spot detection, lane keep, adaptive cruise, and pedestrian detection for years in many cars. Some build in the hardware but then charge hundreds or thousands just to code in the feature.

Safety as an option is not unheard of in the transportation industry. The question is, do these safety features in cars make a fully attentive, experienced driver any better? Or are they there to potentially save a bad, distracted driver from himself?

Not saying Boeing is in the right for making a "disagree light" optional but it is not entirely unprecedented in the transportation industry to features that some might consider "safety-related" optional as well.

Wrong comparison, try brake malfunction warning lamp as optional extra instead

Polot · Fri Mar 22, 2019 1:24 pm

Carlos01 wrote:
scbriml wrote:
It may be that there is something fundamentally wrong with the MAX if Bjorn Fehrm is correct.

https://leehamnews.com/2019/03/22/bjorn ... sh-part-2/
Blowback means the elevator is gradually blown back to lower and lower elevation angles by the pressure of the air as the speed increases. The hydraulic actuators can’t overcome the force of the air and gradually back down if the force of the air grows too strong.

If a blowback problem is confirmed for the 737 at the speeds and altitudes flown, this is what happened at the end of the JT610 flight and probably ET302.

Holy crap. If this theory is correct, what does it mean for the MAX? And in case the blowback-effect is fuelled by the oversized engines that don't really fit on the plane as they should, would that be the end of it? Meaning could it be that the MAX has seen it's final revenue flight already?

The more we learn about all this, the more it looks like there may indeed be more to this than just a bugfix.

It would depend on the conditions that blowback occurs and how the plane gets to that condition. In other words can it occur in normal safe operations or does the pilot have to put the aircraft (purposely or not) into blowback conditions (if all automation ie MCAS is working correctly), and how can a pilot notice and recover from blowback conditions. Keep in mind planes that can deep stall are still certified. Any aircraft is unsafe and faces possible control issues if in unsafe parameters. You just have to make sure you can’t get the plane into that unsafe region unless the pilot purposely does so (barring freak catastrophic failures which would likely down the plane anyways).

It is not clear from the article if the blow back is actually a result of the engines (remember thrust levels are similar between the Max and NG), or as a result of the stabilizer trim (trimmed by MCAS) in conjunction with the pilots not paying close attention to speed.

frmrCapCadet · Fri Mar 22, 2019 1:38 pm

seahawk wrote:
Amiga500 wrote:
crimsonchin wrote:
The MAX will be fine if only because Airbus cannot handle those orders.

Agreed.
Boeing are *very* lucky that neither of the MC-21 or C919 are certified and flying passengers yet - or that Bombardier didn't start with a CS300 then move to a CS500 (instead they erroneously [IMO] did CS100 first).
The duopoly will still exist after the dust settles - if any of the above had happened then it would likely be broken.

Ni it would not be broken.

First there is nothing fundamentally wrong with the MAX. Add an AoA disagree warning and correct the MCAS software and it is just fine. Secondly any competition still lacks the economy of scales advantage and product support to compete with the 2 big players.

Largely agree with this, except (and you likely will agree) non US aviation agencies are going to want the entire certification process confirmed as thorough and safe. This could take a (few?) months. Actually NTSB, President, Senate, and House of Representatives will want the FAA to redo a lot of what they did or should have done. Boeing at this point has few allies in avoiding this.

kelvin933 · Fri Mar 22, 2019 1:46 pm

Aviation737 wrote:
namezero111111 wrote:
dampfnudel wrote:
I wouldn’t be surprised if Lion Air is next to cancel their MAX order. I’m sure Boeing is crossing their fingers right about now that the Chinese carriers don’t get any ideas.

They and others should. The 737MAX is unsafe and never will be safe. It is aerodynamically fatally flawed and only got into the air through a corrupted certification process.. Everyone knows it, time to face the music. Time to cut the losses and start over, Boeing.

What do you mean aerodynamically flawed? Can you explain why it will never be safe? If you meant how the aircraft tends to tilts upward due to its more powerful engine and its placement, wouldn't trim solve this problem? Not to mention, the crash is most likely not even due to its aerodynamics but the MCAS which activated at the wrong time and the wrong place.

The LEAP-1A engines are NOT more powerful than the CFM56-7 engines on the 737NG, they are physically larger and heavier. and are mounted further in front of the wing creating CG issues.
The fact that increasing the thrust in level flight causes the 737MAX to tilt its nose upwards potentially causing high speed stalls is what many people call " aerodynamically flawed",
Boeing developed a "solution" to fix this called MCAS to counteract this tendency.
To make matters worse the training materials for the 737MAX do not mention the MCAS and how it works and pilots have in general not been properly trained on what to do when the MCAS system fails., The JT610 and ET302 crashes appear to be related to how the MCAS "functions".

acechip · Fri Mar 22, 2019 1:58 pm

kelvin933 wrote:
Aviation737 wrote:
namezero111111 wrote:

They and others should. The 737MAX is unsafe and never will be safe. It is aerodynamically fatally flawed and only got into the air through a corrupted certification process.. Everyone knows it, time to face the music. Time to cut the losses and start over, Boeing.

What do you mean aerodynamically flawed? Can you explain why it will never be safe? If you meant how the aircraft tends to tilts upward due to its more powerful engine and its placement, wouldn't trim solve this problem? Not to mention, the crash is most likely not even due to its aerodynamics but the MCAS which activated at the wrong time and the wrong place.

The LEAP-1A engines are NOT more powerful than the CFM56-7 engines on the 737NG, they are physically larger and heavier. and are mounted further in front of the wing creating CG issues.
The fact that increasing the thrust in level flight causes the 737MAX to tilt its nose upwards potentially causing high speed stalls is what many people call " aerodynamically flawed",
Boeing developed a "solution" to fix this called MCAS to counteract this tendency.
To make matters worse the training materials for the 737MAX do not mention the MCAS and how it works and pilots have in general not been properly trained on what to do when the MCAS system fails., The JT610 and ET302 crashes appear to be related to how the MCAS "functions".

That is quite unlike an envelope protection that helps mitigate instability caused by erroneous pilot inputs. Never heard of the A32X series having basic aerodynamic issues corrected by default using the FBW system.

aaexecplat · Fri Mar 22, 2019 2:07 pm

scbriml wrote:
Amiga500 wrote:
seahawk wrote:
First there is nothing fundamentally wrong with the MAX. Add an AoA disagree warning and correct the MCAS software and it is just fine. Secondly any competition still lacks the economy of scales advantage and product support to compete with the 2 big players.

The existence of MCAS would indicate there likely is something fundamentally wrong with the MAX.

It may be that there is something fundamentally wrong with the MAX if Bjorn Fehrm is correct.

https://leehamnews.com/2019/03/22/bjorn ... sh-part-2/
Blowback means the elevator is gradually blown back to lower and lower elevation angles by the pressure of the air as the speed increases. The hydraulic actuators can’t overcome the force of the air and gradually back down if the force of the air grows too strong.

If a blowback problem is confirmed for the 737 at the speeds and altitudes flown, this is what happened at the end of the JT610 flight and probably ET302.

Wow. If this proves to be true, it would explain the final dives of both flights.

Carlos01 · Fri Mar 22, 2019 2:07 pm

Aviation737 wrote:
I bet people would completely forget about this in 1 or 2 years. I mean if half the world's future narrowbody fleet in the future being the MAX, it would be pretty difficult to keep avoiding it in the future. If Boeing really goes for a new clean-sheet design they will be really shooting themselves in the foot. A new design would take at least years for it to roll out of the production lines and they basically won't have any aircraft to compete against the NEOs. Not to mention, it would also be a nightmare for airlines if Boeing stops production on the MAX since they basically won't have any next-gen aircraft to compete with their competitors that have newer aircraft. They basically can't turn to any other manufacturers to provide them with a replacement. The MAX is definately here to stay whether you like it or not.

Well, there's actually 2 things here, which should not be mixed.

1. What makes economically sense for Boeing

2. What Boeing has to do.

The second point has most likely nothing to do with what makes sense for Boeing. Boeing has f-d up so bad, that it's entirely possible that MAX is actually not here to stay, instead it could turn out to be the biggest single failure in all of industrial history to date.

You're quite right that me liking something or not has absolutely nothing to do with any of this. And I wouldn't bet that people will forget this in 1-2 years. The more likely risk is that people are not able to isolate this only to the MAX in the long run, but they put anything with the name "Boeing" in the same basket. That would be unfortunate.

Amiga500 · Fri Mar 22, 2019 2:25 pm

kelvin933 wrote:
The LEAP-1A engines are NOT more powerful than the CFM56-7 engines on the 737NG, they are physically larger and heavier. and are mounted further in front of the wing creating CG issues.
The fact that increasing the thrust in level flight causes the 737MAX to tilt its nose upwards potentially causing high speed stalls is what many people call " aerodynamically flawed",
Boeing developed a "solution" to fix this called MCAS to counteract this tendency.

No no no. That is a misunderstanding of the problem.

At higher angles of attack, the engine nacelle is acting like another mini wing ahead of the main wing[1] - it is that extra lift which is further forward than the main wing which is causing the nose to further tilt up making the problem worse[2].

[1]Due to being bigger and located higher than the 737NG, a part of the main wing is almost like a slotted flap to the nacelle upper surface.

[2]In flight mechanics/dynamics - this is an unstable mode in that it gets worse rather than better if left alone. A big no-no in commercial aviation.

SheikhDjibouti · Fri Mar 22, 2019 2:37 pm

Aviation737 wrote:
I bet people would completely forget about this in 1 or 2 years. I mean if half the world's future narrowbody fleet in the future being the MAX, it would be pretty difficult to keep avoiding it in the future. If Boeing really goes for a new clean-sheet design they will be really shooting themselves in the foot. A new design would take at least years for it to roll out of the production lines and they basically won't have any aircraft to compete against the NEOs. Not to mention, it would also be a nightmare for airlines if Boeing stops production on the MAX since they basically won't have any next-gen aircraft to compete with their competitors that have newer aircraft. They basically can't turn to any other manufacturers to provide them with a replacement. The MAX is definately here to stay whether you like it or not.

"Boeing won't have any aircraft to compete against the NEOs" is your reason for continuing with a flawed design? :banghead:

"it would also be a nightmare for airlines if Boeing stops production on the MAX since they basically won't have any next-gen aircraft to compete with their competitors" WTF?
"they" are presumably airlines that for some reason can only operate Boeing aircraft. What happens if they break that rule; does the CEO turn into a pumpkin at midnight? :roll:

Your ideas remind me of Aeroflot in the worst days of communism;
"Comrade, our glorious manufacturing plants can offer you any aircraft you choose, as long as it is either Ilyushin or Tupolev"

Boeing doesn't have anything to compete in the RJ market, but they survive.
Boeing doesn't have anything to compete against the ATR72, but they survive.
And now for a while it looks as if they will only have the NG to compete against the A320. They will survive.

For years, Airbus didn't have anything to compete against numerous different offerings from Boeing.

And for decades nobody on the planet had anything to compete against the 747.

Get real! Life goes on.

Boeing will take a hit, regroup, redesign, and come out of this stronger and better.
Airlines will have to fly the NG for a few more years, and swallow any extra fuel costs. Or make Boeing cough up the difference.

But the world will not end because the MAX isn't available.

freakyrat · Fri Mar 22, 2019 2:38 pm

gia777 wrote:
I just have a bad feeling B737MAX will be the end of 737 era, just like concorde. It is Time for 797. 737NG was the best 737 ever made. Lion Air will cancel 737Max . Jet airways also in trouble. No time line and serious update from Boeing. A320 will get a huge huge order after this. Things are not looking good for Boeing this year. A big big blow. Simple question... how many of you here are willing to take B737max8 after they fix the problem? How can you be 100% sure they fix the issue...this what boeing needs to give to the world... an evidence and safety assurance on its 737max series to win back

I'm old enough to remember what happened with the Lockheed Electra with the whirl mode phenomana and the engine mount problems. After 2 disastorous crashes and a grounding the engineers fixed the problem with stronger engine mounts and a beefed up wing. The airplane went on to fly for awhile after that and was also developed into an antisubmarine aircraft for the navy in the P3. I'm sure the 737 MAX will survive to.

freakyrat · Fri Mar 22, 2019 3:03 pm

Boeing has been there before. You folks remember the four fatal crashes of the 727? When the airplane arrived it had a unique wing design with leading edge slats and flaps that allowed it to slow down quickly and land on short runways. The aircraft also had a high sink rate that had to be managed properly. The FAA never grounded the aircraft. With extensive pilot training the aircraft the accidents stopped and the aircraft went on to be a success for Boeing and the flying public. It may be different for the MAX and it may not. Onece Boeing develops a software fix and fully tests it and also understands what actually caused the loss of these two aircraft and how to improve training etc. the airplane will probably be successful.

crimsonchin · Fri Mar 22, 2019 3:27 pm

Interested wrote:
Amiga500 wrote:
crimsonchin wrote:
The MAX will be fine if only because Airbus cannot handle those orders.

Agreed.

Boeing are *very* lucky that neither of the MC-21 or C919 are certified and flying passengers yet - or that Bombardier didn't start with a CS300 then move to a CS500 (instead they erroneously [IMO] did CS100 first).

The duopoly will still exist after the dust settles - if any of the above had happened then it would likely be broken.

To the above posts suggesting Boeing will be fine

I guess it depends what you mean by fine long term. Short term it's probably going to get worse before it gets better though

Best case scenario here is an organisation losing 100s of billions of dollars one way or another.

Not sure how much they can afford to lose. Could they afford to lose a trillion dollars? However, one way or another I'm sure the business will somehow survive and prosper again in the future as it's simply too big and important to lose outright

Airbus will certainly be rubbing their hands in the meantime

I also envisage 12 months plus from now it will be operating with an entirely new management structure

So yes the brand will be fine

The profits/losses will be absolutely horrendous and you won't recognise the management

This isn't a minor blip. It's going to to cost a huge amount to sort this and it's going to taken management casualties in key roles to restore any trust

Boeing will survive but I imagine this will prove to be the biggest crisis and certainly by far the most expensive they've ever had to deal with

Unless I'm reading your post wrong, saying the best case scenario for Boeing is losing 100s of billions of dollars in orders is hysterical/alarmist. "100s of billions of orders" covers a huge chunk of the MAX order book, do you really think that's happening.

The only way that happens is if it's revealed that the MAX has a fundamental Comet-like flaw.

Elementalism · Fri Mar 22, 2019 3:53 pm

Carlos01 wrote:
scbriml wrote:
It may be that there is something fundamentally wrong with the MAX if Bjorn Fehrm is correct.

https://leehamnews.com/2019/03/22/bjorn ... sh-part-2/
Blowback means the elevator is gradually blown back to lower and lower elevation angles by the pressure of the air as the speed increases. The hydraulic actuators can’t overcome the force of the air and gradually back down if the force of the air grows too strong.

If a blowback problem is confirmed for the 737 at the speeds and altitudes flown, this is what happened at the end of the JT610 flight and probably ET302.

Holy crap. If this theory is correct, what does it mean for the MAX? And in case the blowback-effect is fuelled by the oversized engines that don't really fit on the plane as they should, would that be the end of it? Meaning could it be that the MAX has seen it's final revenue flight already?

The more we learn about all this, the more it looks like there may indeed be more to this than just a bugfix.

This blowback theory is taken from another msgboard. IMO really shoddy journalism. This effect would I imagine require an unbelievable amount of airspeed to overcome the hydraulics on a 737. This issue could arise and did on WWII fighters. They would enter dives and at an airspeed the pilot would not recover from the dive because he couldnt exert enough force on the yoke to move the elevator. Once that happened the only option was to bail as the plane continued to accelerate making the situation worse. Post war jets solved this issue with Hydrualic systems.

dakota123 · Fri Mar 22, 2019 3:56 pm

Waterbomber2 wrote:
seahawk wrote:
Amiga500 wrote:

Agreed.
Boeing are *very* lucky that neither of the MC-21 or C919 are certified and flying passengers yet - or that Bombardier didn't start with a CS300 then move to a CS500 (instead they erroneously [IMO] did CS100 first).
The duopoly will still exist after the dust settles - if any of the above had happened then it would likely be broken.

Ni it would not be broken.

First there is nothing fundamentally wrong with the MAX. Add an AoA disagree warning and correct the MCAS software and it is just fine. Secondly any competition still lacks the economy of scales advantage and product support to compete with the 2 big players.

Mmmm what are we going to do about the airspeed disagree and loss of altitide indication?
Weren't ET asking the tower for ground speed and altitude readouts?
Stick shaker + AoA disagree + airspeed disagree + altitude disagree.
Just make it a package checklist item and call it ADIRU FAIL.

So why is the ADIRU failing so often and in the same phase of flight?
This is not a sensor problem.
ET and Lion Air would do well to keep a copy ofnthe current hardware and software as evidence before the software patch also silently overwrites any bugs.

AF447 couldn't recover from an airspeed disagree situation at cruise altitude. ADIRU failure in the take-off phase without clear indication is a death trap on its own, MCAS or no MCAS.

The procedure is to crosscheck airspeed on takeoff run, which could have shown up an issue before V1 — and maybe it did, but after V1. If in flight, crosscheck against the standby instrumentation, which has its own pitot and static system, and decide which side is giving correct info. So doesn’t make much sense that they would be asking externally. It’s a commonly trained scenario, or it should be. Will certainly be interesting if there was a valid reason as to why.

I’m not sure too many conclusions can be drawn from AF447. Certainly not the first time, nor the last, that an airspeed disagree happened in cruise, or any phase.

Amiga500 · Fri Mar 22, 2019 4:06 pm

Elementalism wrote:
This blowback theory is taken from another msgboard. IMO really shoddy journalism. This effect would I imagine require an unbelievable amount of airspeed to overcome the hydraulics on a 737. This issue could arise and did on WWII fighters. They would enter dives and at an airspeed the pilot would not recover from the dive because he couldnt exert enough force on the yoke to move the elevator. Once that happened the only option was to bail as the plane continued to accelerate making the situation worse. Post war jets solved this issue with Hydrualic systems.

That "shoddy journalist" is an aeronautical engineer and former fighter pilot.

He also suggested he had first hand experience in it on the Saab Draken.

Hydraulics does not mean the system is immune to force feedback - ever drive the front wheel of your car into a kerb and get a kickback through the steering wheel?

seahawk · Fri Mar 22, 2019 4:15 pm

scbriml wrote:
Amiga500 wrote:
seahawk wrote:
First there is nothing fundamentally wrong with the MAX. Add an AoA disagree warning and correct the MCAS software and it is just fine. Secondly any competition still lacks the economy of scales advantage and product support to compete with the 2 big players.

The existence of MCAS would indicate there likely is something fundamentally wrong with the MAX.

It may be that there is something fundamentally wrong with the MAX if Bjorn Fehrm is correct.

https://leehamnews.com/2019/03/22/bjorn ... sh-part-2/
Blowback means the elevator is gradually blown back to lower and lower elevation angles by the pressure of the air as the speed increases. The hydraulic actuators can’t overcome the force of the air and gradually back down if the force of the air grows too strong.

If a blowback problem is confirmed for the 737 at the speeds and altitudes flown, this is what happened at the end of the JT610 flight and probably ET302.

It would explain the flight profiles of the crashed planes. Yet fixing it is not that hard you need to limit the maximum stabilizer trim for MCAS to apply and probably have it consider airspeed as well. The cynic in me would thna point out that Boeing needs up with about 80% of the work of an FBW plane, but none of the advantages, but that is Boeing´s problem.

dakota123 · Fri Mar 22, 2019 4:25 pm

Amiga500 wrote:
kelvin933 wrote:
The LEAP-1A engines are NOT more powerful than the CFM56-7 engines on the 737NG, they are physically larger and heavier. and are mounted further in front of the wing creating CG issues.
The fact that increasing the thrust in level flight causes the 737MAX to tilt its nose upwards potentially causing high speed stalls is what many people call " aerodynamically flawed",
Boeing developed a "solution" to fix this called MCAS to counteract this tendency.

No no no. That is a misunderstanding of the problem.

At higher angles of attack, the engine nacelle is acting like another mini wing ahead of the main wing[1] - it is that extra lift which is further forward than the main wing which is causing the nose to further tilt up making the problem worse[2].

[1]Due to being bigger and located higher than the 737NG, a part of the main wing is almost like a slotted flap to the nacelle upper surface.

[2]In flight mechanics/dynamics - this is an unstable mode in that it gets worse rather than better if left alone. A big no-no in commercial aviation.

Except that it merely leads to a lessening of stick force gradient if what I’ve read is true. So at some point it becomes easier to get to the critical AOA instead of ever more difficult. (Leaving aside the idea per Boeing that MCAS is supposed to mainly offer protection in steep turns, when load factors start up the hockey stick.) Not ideal and not allowable in any case, but MCAS seems to me like a reasonable answer. A bit disconcerting it takes 2.5* ND rather than 0.6* as predicted, to be sure.

Elementalism · Fri Mar 22, 2019 4:25 pm

Amiga500 wrote:
Elementalism wrote:
This blowback theory is taken from another msgboard. IMO really shoddy journalism. This effect would I imagine require an unbelievable amount of airspeed to overcome the hydraulics on a 737. This issue could arise and did on WWII fighters. They would enter dives and at an airspeed the pilot would not recover from the dive because he couldnt exert enough force on the yoke to move the elevator. Once that happened the only option was to bail as the plane continued to accelerate making the situation worse. Post war jets solved this issue with Hydrualic systems.

That "shoddy journalist" is an aeronautical engineer and former fighter pilot.

He also suggested he had first hand experience in it on the Saab Draken.

Hydraulics does not mean the system is immune to force feedback - ever drive the front wheel of your car into a kerb and get a kickback through the steering wheel?

And so what about his background? That doesn't have anything to do with him of using a msgboard post as a basis for some theory about run away dive mechanics on a 737.

A kickback through the steering wheel is not the same as what he is describing via the msgboard post. The aircraft has entered into a situation no amount of force can bring the nose up. This would require a lot of airspeed for the hydraulics on a 737 to get to that point.

birdbrainz · Fri Mar 22, 2019 4:37 pm

kelvin933 wrote:
The fact that increasing the thrust in level flight causes the 737MAX to tilt its nose upwards potentially causing high speed stalls is what many people call " aerodynamically flawed",

Isn't it true that most aircraft pitch up as thrust is increased, and that's usually considered a good thing?

I recall that the Piper Jet had the opposite problem of pitching down as power is increased due to its high mounted engine, and that's considered highly undesirable for obvious reasons.

Amiga500 · Fri Mar 22, 2019 4:38 pm

dakota123 wrote:
Except that it merely leads to a lessening of stick force gradient if what I’ve read is true.

Unfortunately that is mostly Boeing PR bull with a small kernel of truth.

It is a very rudimentary stall protection system... the kind of thing that a kid on their first year out of university might dream up over a summer internship.

If they were truly wanting to offer a system that affected stick force gradient, it would not vary in the rather "blocky" manner it does.

asdf · Fri Mar 22, 2019 4:39 pm

birdbrainz wrote:
kelvin933 wrote:
The fact that increasing the thrust in level flight causes the 737MAX to tilt its nose upwards potentially causing high speed stalls is what many people call " aerodynamically flawed",

Isn't it true that most aircraft pitch up as thrust is increased, and that's usually considered a good thing?

they shouldnt if the center of drag is identical with the center of gravity, isnt it?

Amiga500 · Fri Mar 22, 2019 4:44 pm

Elementalism wrote:
And so what about his background? That doesn't have anything to do with him of using a msgboard post as a basis for some theory about run away dive mechanics on a 737.

Well, given he noted his personal experience of it (in a hydraulically actuated aircraft), then I think he's probably somewhat aware of where it can lead.

Elementalism wrote:
A kickback through the steering wheel is not the same as what he is describing via the msgboard post. The aircraft has entered into a situation no amount of force can bring the nose up. This would require a lot of airspeed for the hydraulics on a 737 to get to that point.

What is different? Instead of a kerb you have air. Have you never seen hydraulics max out on what they can do?!? Stick 10 ton on the back of my dad's tractor and it ain't lifting it.

Your missing the bit about MCAS retriming the H-Stab such that you need 95%+ upward deflection on the elevators to counter the downward trim.

Do you know the gearing of the actuators on the 737? I'll tell you this - if they were utterly immune to blowback far beyond the design range of the aircraft, it'd mean they are too heavy - and an elevator needing full upward deflection when the stabiliser is on full down trim at low altitude and high speed is far outside the typical design range of that subsystem.

Amiga500 · Fri Mar 22, 2019 4:46 pm

asdf wrote:
birdbrainz wrote:
kelvin933 wrote:
The fact that increasing the thrust in level flight causes the 737MAX to tilt its nose upwards potentially causing high speed stalls is what many people call " aerodynamically flawed",

Isn't it true that most aircraft pitch up as thrust is increased, and that's usually considered a good thing?

they shouldnt if the center of drag is identical with the center of gravity, isnt it?

Strictly speaking it'd be centre of mass but yeah.

Generally on a low wing aircraft with underslung engines, power up = pitch up. You can mess around with thrustlines (attitude of engine w.r.t aircraft) so that the thrust line more or less intersects the centre of mass (as viewed from the side) - which would reduce/eradicate the effect - but that then means your adding downward force which must be grabbed back through wing lift ==> drag.

Interested · Fri Mar 22, 2019 4:48 pm

crimsonchin wrote:
Interested wrote:
Amiga500 wrote:

Agreed.

Boeing are *very* lucky that neither of the MC-21 or C919 are certified and flying passengers yet - or that Bombardier didn't start with a CS300 then move to a CS500 (instead they erroneously [IMO] did CS100 first).

The duopoly will still exist after the dust settles - if any of the above had happened then it would likely be broken.

To the above posts suggesting Boeing will be fine

I guess it depends what you mean by fine long term. Short term it's probably going to get worse before it gets better though

Best case scenario here is an organisation losing 100s of billions of dollars one way or another.

Not sure how much they can afford to lose. Could they afford to lose a trillion dollars? However, one way or another I'm sure the business will somehow survive and prosper again in the future as it's simply too big and important to lose outright

Airbus will certainly be rubbing their hands in the meantime

I also envisage 12 months plus from now it will be operating with an entirely new management structure

So yes the brand will be fine

The profits/losses will be absolutely horrendous and you won't recognise the management

This isn't a minor blip. It's going to to cost a huge amount to sort this and it's going to taken management casualties in key roles to restore any trust

Boeing will survive but I imagine this will prove to be the biggest crisis and certainly by far the most expensive they've ever had to deal with

Unless I'm reading your post wrong, saying the best case scenario for Boeing is losing 100s of billions of dollars in orders is hysterical/alarmist. "100s of billions of orders" covers a huge chunk of the MAX order book, do you really think that's happening.

The only way that happens is if it's revealed that the MAX has a fundamental Comet-like flaw.

They've got 4,650 Max planes on order approx. Their total order book for planes is 5,900 so this is their cash cow.

49 are already in the process of being cancelled by the Indonesian airline at a cost of approx 5 billion dollars based on the article I read today.

Please everybody who thinks that's the only order they will lose sign your name below and let's see

Just losing 20 per cent of their existing orders takes 100 billion dollars off their order list alone

The cost of Grounding until June and compensation will be huge.

I also believe the value of the business has dropped in excess of 30 billion US dollars and counting since the second crash?

100s of billions of dollars is not hysterical to say the least

Some say the plane may not even get certified to fly again

That's 500 billion US dollars of orders at risk approx just from existing orders. I'm sure they would be expecting new orders on a monthly basis as well

Sooner787 · Fri Mar 22, 2019 4:55 pm

Very intersting column by Bjorn Fehrm in Leeham newsletter this morning
regarding " Blowback" syndrome

https://leehamnews.com/2019/03/22/bjorn ... sh-part-2/

speedking · Fri Mar 22, 2019 5:21 pm

Amiga500 wrote:
Elementalism wrote:
And so what about his background? That doesn't have anything to do with him of using a msgboard post as a basis for some theory about run away dive mechanics on a 737.

Well, given he noted his personal experience of it (in a hydraulically actuated aircraft), then I think he's probably somewhat aware of where it can lead.

Elementalism wrote:
A kickback through the steering wheel is not the same as what he is describing via the msgboard post. The aircraft has entered into a situation no amount of force can bring the nose up. This would require a lot of airspeed for the hydraulics on a 737 to get to that point.

What is different? Instead of a kerb you have air. Have you never seen hydraulics max out on what they can do?!? Stick 10 ton on the back of my dad's tractor and it ain't lifting it.

Your missing the bit about MCAS retriming the H-Stab such that you need 95%+ upward deflection on the elevators to counter the downward trim.

Do you know the gearing of the actuators on the 737? I'll tell you this - if they were utterly immune to blowback far beyond the design range of the aircraft, it'd mean they are too heavy - and an elevator needing full upward deflection when the stabiliser is on full down trim at low altitude and high speed is far outside the typical design range of that subsystem.

Isn't the hydraulic pressure limited with a relief valve to prevent such force that it would lead to damaged control surfaces due to high aerodynamic force? Like the speed breaks in some planes have?

freakyrat · Fri Mar 22, 2019 5:53 pm

What were seeing if I read the new articles correctly is that the final MAX product MCAS system did not comply with the original specs that limited the MCAS system to 0.6 % nose down trim. There was also no redundancy built into the system which now Boeing will build in. The software and some hardware updates will put the MCAS system back to the original specs which should make the aircraft very safe to operate.

Morvious · Fri Mar 22, 2019 6:22 pm

freakyrat wrote:
What were seeing if I read the new articles correctly is that the final MAX product MCAS system did not comply with the original specs that limited the MCAS system to 0.6 % nose down trim. There was also no redundancy built into the system which now Boeing will build in. The software and some hardware updates will put the MCAS system back to the original specs which should make the aircraft very safe to operate.

MCAS is a feature that only a few knew about (Why, what was there to hide?). This “simple” software “fix” will be properly investigated this time and not only by the FAA. I also believe the whole MCAS system will be investigated now and why it is here in the first place.

If all goes as simple as you pointed it out to be, Boeing will be very lucky, I just don’t see it happening this way.

Interested · Fri Mar 22, 2019 6:29 pm

Morvious wrote:
freakyrat wrote:
What were seeing if I read the new articles correctly is that the final MAX product MCAS system did not comply with the original specs that limited the MCAS system to 0.6 % nose down trim. There was also no redundancy built into the system which now Boeing will build in. The software and some hardware updates will put the MCAS system back to the original specs which should make the aircraft very safe to operate.

MCAS is a feature that only a few knew about (Why, what was there to hide?). This “simple” software “fix” will be properly investigated this time and not only by the FAA. I also believe the whole MCAS system will be investigated now and why it is here in the first place.

If all goes as simple as you pointed it out to be, Boeing will be very lucky, I just don’t see it happening this way.

Isn't it needed because the plane can't fly safely without it?

So they've designed a plane that now has a feature that can fail that wouldn't need to be there with a more safely designed plane

Safety has gone backwards when it should be moving forwards?

Whether or not that keeps the plane grounded or not who knows but it's not exactly a selling point is it?

hilram · Fri Mar 22, 2019 6:31 pm

freakyrat wrote:
What were seeing if I read the new articles correctly is that the final MAX product MCAS system did not comply with the original specs that limited the MCAS system to 0.6 % nose down trim. There was also no redundancy built into the system which now Boeing will build in. The software and some hardware updates will put the MCAS system back to the original specs which should make the aircraft very safe to operate.

Even if all that smooth sailing through test and certification by the FAA were to come true, like Boeing leadership ensures us, there will still be an independent Re-Certification in Europe and Canada, and maybe Asia. 737 MAX deliveries will not resume in “no time “. Likely, MAX without redundant AOA sensors will never fly Pax in Europe again.

SheikhDjibouti · Fri Mar 22, 2019 7:04 pm

freakyrat wrote:
What were seeing if I read the new articles correctly is that the final MAX product MCAS system did not comply with the original specs that limited the MCAS system to 0.6 % nose down trim. There was also no redundancy built into the system which now Boeing will build in. The software and some hardware updates will put the MCAS system back to the original specs which should make the aircraft very safe to operate.

Er…. no.
That is the very definition of a "kludge"

Boeing did not increase MCAS limit from 0.6deg to 2.5deg simply because it was a nice number. They did it because (Boeing?) test pilots deemed more MCAS authority was necessary.

Now, in order to satisfy FAA documentation you propose they revert to the original 0.6deg, and somehow claim it "should make the aircraft very safe to operate". :banghead:

The tail should not be wagging the dog.

You do not invite a test pilot to check out your baby, and then ignore his recommendations because it will mess up your paperwork. :hissyfit:

Interested · Fri Mar 22, 2019 7:07 pm

SheikhDjibouti wrote:
freakyrat wrote:
What were seeing if I read the new articles correctly is that the final MAX product MCAS system did not comply with the original specs that limited the MCAS system to 0.6 % nose down trim. There was also no redundancy built into the system which now Boeing will build in. The software and some hardware updates will put the MCAS system back to the original specs which should make the aircraft very safe to operate.

Er…. no.
That is the very definition of a "kludge"

Boeing did not increase MCAS limit from 0.6deg to 2.5deg simply because it was a nice number. They did it because (Boeing?) test pilots deemed more MCAS authority was necessary.

Now, in order to satisfy FAA documentation you propose they revert to the original 0.6deg, and somehow claim it "should make the aircraft very safe to operate".

The tail should not be wagging the dog.

You do not invite a test pilot to check out your baby, and then ignore his recommendations because it will mess up your paperwork.

So what can Boeing do that is simple to make these planes at least as safe as the 737s they are replacing?

namezero111111 · Fri Mar 22, 2019 7:18 pm

Interested wrote:
So what can Boeing do that is simple to make these planes at least as safe as the 737s they are replacing?

I'm sure they'd be willing to pay anyone a generous amount for a viable solution to that conundrum.

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