SheikhDjibouti wrote:

The only other option is the grand conspiracy; Ethiopia knows it was a bomb, but is busy hiding all the evidence.....

LTC8K6 wrote:

Improving MCAS doesn't necessarily make it the cause of the crash, though.

32andBelow wrote:

Explosion that made the plane uncontrollable. It was at 1000ft. How big do you think the field would be?

Shaky wrote:

Please explain how you know the aircraft was at 1,000 ft?
Please explain the inconsistent speed data at take-off?
Please explain the handling issues reported shortly after take-off?

32andBelow wrote:

Could easily have been an altimeter bomb. Or detonated by a passenger.
The NTSB just got there. I doubt Ethiopian knows much of anything tbh. I think NTSB and Boeing will take the primary lead. The easiest explanation is usually the most likely.

JoeCanuck wrote:

and permanently disabled with a pair of cutoff switches on the yoke.

Gonzalo wrote:

Aerolíneas Argentinas, Aeroméxico, Gol and many other carriers are grounding the fleet of 738Max in the last few hours. This is a major trouble for Boeing and the stocks will continue to fall if the company doesn’t take a strong action to make a public commitment to solve any problem and warrant the safety of the model in a very short time.
I love Boeing planes and this is really sad, but let’s face it, the things have been managed horribly from a public view standpoint and the lack of a strong response by Boeing is not helping.

Rgds.
G.

GEUltraFan9XGTF wrote:

Do pilots have to sign an NDA about performance characteristics?

Reefwiz wrote:

Can't believe that no one has posted this update from Reuters.

So much for 1700 posts of theory and fantasy.

Looks more like fire and or explosion or hull intrusion is a strong possibility.

https://www.reuters.com/article/us-ethi ... SKBN1QS1LJ

Tamirat Abera, 25, was walking past the field at the time. He said the plane turned sharply, trailing white smoke and items like clothes and papers, then crashed about 300 meters away.

Half a dozen witnesses interviewed by Reuters in the farmland where the plane came down reported smoke billowing out behind, while four of them also described a loud sound.

“It was a loud rattling sound. Like straining and shaking metal,” said Turn Buzuna, a 26-year-old housewife and farmer who lives about 300 meters (328 yards) from the crash site.

Paper and clothing dropping from the sky as the plane trailed smoke and sparks (fire)... doesn't sound like software, eh?

hamiltondaniel wrote:

SheikhDjibouti wrote:

The only other option is the grand conspiracy; Ethiopia knows it was a bomb, but is busy hiding all the evidence.....

Another either/or fallacy (sixth or seventh in last three pages, since I started counting).

hamiltondaniel wrote:

I'm going to officially proclaim myself the logic checker of this thread. Somebody needs to.

FredrikHAD wrote:

khobar95 wrote:

... The Aviation Herald learned that the loss of altitude had been caused by two angle of attack sensors having frozen in their positions ...

What puzzles me is that the computers in these advanced aircraft cannot make use of the vast amount of sensors in a more intelligent way. It is (I know it is) entirely possible to give a pretty good estimate of AoA based on other input than only AoA sensors. It could be derived from throttle, actual thrust (is that available by the way?), rudder deflection, speed, altitude and perhaps some other data. This type of "secondary" data could be used to warn the pilots that a set of sensors MAY be wrong and give them the option to deactivate systems that are dependant on them, or automatically switch to another sensor if available. In the case with both AoA sensors frozen, the system could even decide to use the derived AoA and warn that this is the case.

A MAX8/9 that has had no extraordinary stick input, just rotated at a speed that is "normal", is accelerating as expected and is climbing at an expected rate cannot all of a sudden go into an angle of attack of epic proportions.

I sometimes refer to the CRJ-200PF crash in Sweden Jan 8th 2016. The captain's "Primary Flight Display showed a pitch angle of 15 degrees nose up with speed and altitude remaining unchanged" [quote from the investigation]. The #1 Inertial Reference System (IRS) (displayed on the left side PFD) had started indicating a pitch that was both untrue and completely unrealistic. Sadly, the captain didn't even consult the FO but started pitching down, causing a dive, and from there everything "went south". The captain was probably startled by the high pitch and started to "counteract" that by lowering the nose. The FO didn't understand a thing because his PFD was showing the correct pitch. Both pilots must have felt all was normal before the captain saw the incorrect pitch on the PFD. If the pitch had been that high, speed would have decreased and/or altitude increased, all possible to "sense" by a human, and, more interestingly, by the computers!!! Humans can be fooled into believing all is normal (spatial disorientation, somatogravic illusion and other phenomena) but computers with enough sensors can decide that at least one sensor is incorrect, perhaps even determine which one. In this case, as speed, altitude and one IRS were consistent with each other, that would wash out pitch from the #1 IRS as the culprit. One action could be to stop displaying pitch on the left PFD, or draw a red cross over it, still displaying the false value. A warning that the #1 IRS was probably giving a false value should be easy to produce.

I do understand that such modifications cannot be done easily, but if the values from the present systems are fed to a separate computer, it could at least warn the pilots that something is wrong, and they can be aided into deciding how to troubleshoot that. This type of "secondary" or "synthetic" readings should be considered in the future at least. If this had been the case in the MAX, it might just have averted both crashes.

/Fredrik

zuckie13 wrote:

gia777 wrote:

https://finance.yahoo.com/news/pilots-reported-issues-us-boeing-204120870.html
This article explain how the autpilot at B737MAX have issues

Airline pilots on at least two U.S. flights have reported that an automated system seemed to cause their Boeing 737 Max planes to tilt down suddenly.

The pilots said that soon after engaging the autopilot on Boeing 737 Max 8 planes, the nose tilted down sharply. In both cases, they recovered quickly after disconnecting the autopilot.

As described by the pilots, however, the problem did not appear related to a new automated anti-stall system that is suspected of contributing to a deadly October crash in Indonesia.

The Max 8 is at the center of a growing global ban by more than 40 countries following a second fatal crash, this time in Ethiopia, in less than five months. In the U.S., however, the Federal Aviation Administration and airlines continued to permit the planes to fly.

American Airlines and Southwest Airlines operate the 737 Max 8, and United Airlines flies a slightly larger version, the Max 9. All three carriers vouched for the safety of Max aircraft on Wednesday

The pilot reports were filed last year in a data base compiled by NASA. They are voluntary safety reports and do not publicly reveal the names of pilots, the airlines or the location of the incidents.

It was unclear whether the accounts led to any actions by the FAA or the pilots' airlines.

In one report, an airline captain said that immediately after putting the plane on autopilot, the co-pilot called out "Descending," followed by an audio cockpit warning, "Don't sink, don't sink!"

The captain immediately disconnected the autopilot and resumed climbing.

"With the concerns with the MAX 8 nose down stuff, we both thought it appropriate to bring it to your attention," the captain wrote. "Best guess from me is airspeed fluctuation" due to a brief weather system overwhelming the plane's automation.

On another flight, the co-pilot said that seconds after engaging the autopilot, the nose pitched downward and the plane began descending at 1,200 to 1,500 feet (365 to 460 meters) per minute. As in the other flight, the plane's low-altitude-warning system issued an audio warning. The captain disconnected autopilot, and the plane began to climb.

Possible the planes were not trimmed well when AP was engaged. Maybe pilot engaged the AP and trim was so bad it nosed down because it had to make a major adjustment?

skuds wrote:

Condolences to the families of the lost.

Good evening, My first post... Long time lurker... Please be gentle.
After slogging thru this thread the last couple of days, I’ve learned a lot... Coo-does to most!

Referencing FredrikHAD‘s comments, and acknowledging that I have no experience in aircraft flight systems... However, I do have 35 years of human space flight ground systems engineering and management experience in Houston.

I’m wondering if there is systems integration issues between the 738’s aircraft’s autopilot system and the seemingly add-in MCAS that today’s s/w upgrade may address. The autopilot transition’s dipping of the aircraft’s nose is most disconcerting.

Questions I have include: Do all the sensors live on a network using standard communications protocols or are they point-to-point, e.g., is it possible to efficiently add additional redundant sensors? Is the base MCAS capable of taking on additional inputs? Is there a general communications pathway between the autopilot, flap settings and MCAS that goes beyond “I’m on and therefore you’re off”? e.g., Do they interrogate each other and pass key flight parameters?

Or... Is this a closed system that would require reengineering of each subsystem, a bazillion $s and recertifications?
Or, could this software “patch” address some or all of these key integration issues?

LTC8K6 wrote:

Improving MCAS doesn't necessarily make it the cause of the crash, though.

32andBelow wrote:

spacecadet wrote:

Reefwiz wrote:

Can't believe that no one has posted this update from Reuters.

So much for 1700 posts of theory and fantasy.

It was posted dozens of pages ago, before Reuters even learned of it.

Paper and clothing dropping from the sky as the plane trailed smoke and sparks (fire)... doesn't sound like software, eh?

If the witness is correct, which they are more than likely not.

That's why not a lot of credence has been given to it. Witnesses - especially *one* witness - are very rarely reliable. If there's a pattern among dozens of witnesses, then ok, you look for general things you can take away from that. But very few people - even if they know anything about aviation - can accurately describe what they're seeing in an unusual situation like this. In the Northwest 255 accident, for example, there were other pilots who watched that flight take off and swore that the flaps were down. They weren't. And those were *pilots*. You expect a layperson to do better?

Ignore the witnesses until there's some corroborating evidence, which there is not right now. A single witness statement should be treated as at best "interesting" until proven otherwise, but it's certainly no smoking gun, or even necessarily evidence of anything.

He said half a dozen witnesses but you cut that off his quote.

NWNightfly wrote:

WIederling wrote:

Interpretation:
MCAS trimmed high and the activated autopilot corrected that ASAP.
This would indicate that MCAS and flight displays get wrong ( increased AoA) information
while the AP gets the correct one. That is a real can of worms, man!

Except isn't it pretty much SOP throughout the world to activate the autopilot before fully retracting the flaps? In which case, once again, MCAS would have never been engaged.

NWNightfly wrote:

WIederling wrote:

1010101 wrote:

This article https://m.huffpost.com/us/entry/us_5c88 ... 0ddae54075 has two reports of a sudden pitch down after the autopilot is engaged. This would support the notion that something more than MCAS is involved.

Edited to add this direct link to the pilot asrs report. https://www.documentcloud.org/documents ... 10/a486269

Interpretation:
MCAS trimmed high and the activated autopilot corrected that ASAP.
This would indicate that MCAS and flight displays get wrong ( increased AoA) information
while the AP gets the correct one. That is a real can of worms, man!

Except isn't it pretty much SOP throughout the world to activate the autopilot before fully retracting the flaps? In which case, once again, MCAS would have never been engaged.

maui19 wrote:

There is something that has been nagging at me about both these crashes. In both cases, the pilots were struggling with the aricraft, but did seem to be overcoming the problem (MCAS) as shown by their continuing to climb, albeit haltingly. But at the end, both planes encountered something that caused them to nosedive. I feel like this is a big piece of the puzzle is yet to be identified. Perhaps the final problem occurs when they try to turn the AC to return to the airport. I think there's more to this than just MCAS and a bad sensor. But who knows.

Waterbomber2 wrote:

I have a theory that could explain the AOA sensor malfunction indication and the crashes, while also explaining why MCAS is wrongly accused of being the main culprit.

If you look at the position of the engines on the MAX 8, they have been brought forward and up, to maintain ground clearance despite installing a larger fan.
The MCAS system has been added to counter the balance effects compared to the -800, but let's leave this aside for a minute and focus purely on aerodynamics.
My theory is that due to the new position and size of the fan, where the fan intake's upper edge is protruding above the wing's extrados even when the aircraft is level VS. ram air, the MAX 8's engines may be too high and sucking a lot of ram air that previously came into contact with the wing to contribute to lift generation, causing the wing to locally stall prematurely. In addition, it's possible that the position of the new engines vis a vis the wings is causing ram air to become turbulent ahead of the wing and creating a shadow effect for the wing sections situated behind the engine.
Basically, my theory is that the higher position of the engines is reducing the flight envelope of the MAX 8 by causing premature, undetected stalls.
In my flight training days, we would practice the powered stall recovery with the instructor and this reminds me of that phenomenon.

-it explains why the Lion Air aircraft went out of envelope in the climb after take-off: an already high angle of attack during climb, followed by a local undetected stall of the wing, which expands into a power-on stall potentially supported by flap retraction.
-The AOA sensors indicate a malfunction because they are outside preset parameters. Essentially, they are not malfunctioning, but they appear to be malfunctioning as the aircraft is in a stall but not within the expected parameters of a stall.
-The trim may be running amock and contributing to a difficult recovery, again, because it is operating outside the parameters.

Please look at the position of the engines and compare them to the -800.
They are crazy high and imagine how they will be way above the wing's leading edge in a climb with a higher angle of attack.

Waterbomber2 wrote:

I have a theory that could explain the AOA sensor malfunction indication and the crashes, while also explaining why MCAS is wrongly accused of being the main culprit.

If you look at the position of the engines on the MAX 8, they have been brought forward and up, to maintain ground clearance despite installing a larger fan.
The MCAS system has been added to counter the balance effects compared to the -800, but let's leave this aside for a minute and focus purely on aerodynamics.
My theory is that due to the new position and size of the fan, where the fan intake's upper edge is protruding above the wing's extrados even when the aircraft is level VS. ram air, the MAX 8's engines may be too high and sucking a lot of ram air that previously came into contact with the wing to contribute to lift generation, causing the wing to locally stall prematurely. In addition, it's possible that the position of the new engines vis a vis the wings is causing ram air to become turbulent ahead of the wing and creating a shadow effect for the wing sections situated behind the engine.
Basically, my theory is that the higher position of the engines is reducing the flight envelope of the MAX 8 by causing premature, undetected stalls.
In my flight training days, we would practice the powered stall recovery with the instructor and this reminds me of that phenomenon.

-it explains why the Lion Air aircraft went out of envelope in the climb after take-off: an already high angle of attack during climb, followed by a local undetected stall of the wing, which expands into a power-on stall potentially supported by flap retraction.
-The AOA sensors indicate a malfunction because they are outside preset parameters. Essentially, they are not malfunctioning, but they appear to be malfunctioning as the aircraft is in a stall but not within the expected parameters of a stall.
-The trim may be running amock and contributing to a difficult recovery, again, because it is operating outside the parameters.


Please look at the position of the engines and compare them to the -800.
They are crazy high and imagine how they will be way above the wing's leading edge in a climb with a higher angle of attack.

ikramerica wrote:

Waterbomber2 wrote:

I have a theory that could explain the AOA sensor malfunction indication and the crashes, while also explaining why MCAS is wrongly accused of being the main culprit.

If you look at the position of the engines on the MAX 8, they have been brought forward and up, to maintain ground clearance despite installing a larger fan.
The MCAS system has been added to counter the balance effects compared to the -800, but let's leave this aside for a minute and focus purely on aerodynamics.
My theory is that due to the new position and size of the fan, where the fan intake's upper edge is protruding above the wing's extrados even when the aircraft is level VS. ram air, the MAX 8's engines may be too high and sucking a lot of ram air that previously came into contact with the wing to contribute to lift generation, causing the wing to locally stall prematurely. In addition, it's possible that the position of the new engines vis a vis the wings is causing ram air to become turbulent ahead of the wing and creating a shadow effect for the wing sections situated behind the engine.
Basically, my theory is that the higher position of the engines is reducing the flight envelope of the MAX 8 by causing premature, undetected stalls.
In my flight training days, we would practice the powered stall recovery with the instructor and this reminds me of that phenomenon.

-it explains why the Lion Air aircraft went out of envelope in the climb after take-off: an already high angle of attack during climb, followed by a local undetected stall of the wing, which expands into a power-on stall potentially supported by flap retraction.
-The AOA sensors indicate a malfunction because they are outside preset parameters. Essentially, they are not malfunctioning, but they appear to be malfunctioning as the aircraft is in a stall but not within the expected parameters of a stall.
-The trim may be running amock and contributing to a difficult recovery, again, because it is operating outside the parameters.

Please look at the position of the engines and compare them to the -800.
They are crazy high and imagine how they will be way above the wing's leading edge in a climb with a higher angle of attack.

But how on earth would this not have been experienced by Boeing in modeling, wind tunnel testing, regular flight testing, envelope establishment, and 2 years in service around the world?

I would still think, that even if what you are saying is correct, it has to be enhanced by some OTHER event that compounds it, some sort of malfunction.

Waterbomber2 wrote:

I have a theory that could explain the AOA sensor malfunction indication and the crashes, while also explaining why MCAS is wrongly accused of being the main culprit.

If you look at the position of the engine intakes on the MAX 8, they have been brought forward and up, to maintain ground clearance despite installing a larger fan.
The MCAS system has been added to counter the balance effects compared to the -800, but let's leave this aside for a minute and focus purely on aerodynamics.
My theory is that due to the new position and size of the fan, where the fan intake's upper edge is protruding above the wing's extrados even when the aircraft is level VS. ram air, the MAX 8's engines may be too high and sucking a lot of ram air that previously came into contact with the wing to contribute to lift generation, causing the wing to locally stall prematurely. In addition, it's possible that the position of the new engines vis a vis the wings is causing ram air to become turbulent ahead of the wing and creating a shadow effect for the wing sections situated behind the engine.
Basically, my theory is that the higher position of the engine intakes is reducing the flight envelope of the MAX 8 by causing premature, undetected stalls.
In my flight training days, we would practice the powered stall recovery with the instructor and this reminds me of that phenomenon.

-it explains why the Lion Air aircraft went out of envelope in the climb after take-off: an already high angle of attack during climb, followed by a local undetected stall of the wing, which expands into a power-on stall potentially supported by flap retraction.
-The AOA sensors indicate a malfunction because they are outside preset parameters. Essentially, they are not malfunctioning, but they appear to be malfunctioning as the aircraft is in a stall but not within the expected parameters of a stall.
-The trim may be running amock and contributing to a difficult recovery, again, because it is operating outside the parameters.


Please look at the high position of the engine intakes and compare them to the -800.
They are crazy high and imagine how they will be shadowing a good portion of the wing's leading edge in a climb with a higher angle of attack.



https://static.seattletimes.com/wp-cont ... 60x967.jpg

tvarad wrote:

From the Ethiopian Airlines CEO through Richard Quest (their travel reporter), CNN is reporting that the airplane had flight control issues:

https://twitter.com/CNNnewsroom/status/ ... index.html

Surely the pilots would have gotten the memo on the MCAS issue after the Lion Air crash and must have tried the fix(es) so if they still couldn't fly it, there's a high probability that the loss of control points to something else.

Waterbomber2 wrote:

ikramerica wrote:

Waterbomber2 wrote:

I have a theory that could explain the AOA sensor malfunction indication and the crashes, while also explaining why MCAS is wrongly accused of being the main culprit.

If you look at the position of the engines on the MAX 8, they have been brought forward and up, to maintain ground clearance despite installing a larger fan.
The MCAS system has been added to counter the balance effects compared to the -800, but let's leave this aside for a minute and focus purely on aerodynamics.
My theory is that due to the new position and size of the fan, where the fan intake's upper edge is protruding above the wing's extrados even when the aircraft is level VS. ram air, the MAX 8's engines may be too high and sucking a lot of ram air that previously came into contact with the wing to contribute to lift generation, causing the wing to locally stall prematurely. In addition, it's possible that the position of the new engines vis a vis the wings is causing ram air to become turbulent ahead of the wing and creating a shadow effect for the wing sections situated behind the engine.
Basically, my theory is that the higher position of the engines is reducing the flight envelope of the MAX 8 by causing premature, undetected stalls.
In my flight training days, we would practice the powered stall recovery with the instructor and this reminds me of that phenomenon.

-it explains why the Lion Air aircraft went out of envelope in the climb after take-off: an already high angle of attack during climb, followed by a local undetected stall of the wing, which expands into a power-on stall potentially supported by flap retraction.
-The AOA sensors indicate a malfunction because they are outside preset parameters. Essentially, they are not malfunctioning, but they appear to be malfunctioning as the aircraft is in a stall but not within the expected parameters of a stall.
-The trim may be running amock and contributing to a difficult recovery, again, because it is operating outside the parameters.

Please look at the position of the engines and compare them to the -800.
They are crazy high and imagine how they will be way above the wing's leading edge in a climb with a higher angle of attack.

But how on earth would this not have been experienced by Boeing in modeling, wind tunnel testing, regular flight testing, envelope establishment, and 2 years in service around the world?

I would still think, that even if what you are saying is correct, it has to be enhanced by some OTHER event that compounds it, some sort of malfunction.

I think that it can be explained by the fact that modelling is not advanced enough or does not take into account the air sucked in by an engine as this was not as much of a factor in previous designs.
For instance in wind tunnel testing, the engines are just static elements and don't have a fan in them that sucks in ram air.

trpmb6 wrote:

PlanesNTrains wrote:

slider wrote:

Well, this could be a tragic by-product of trying to upgrade a warmed-over 50 year old airframe instead of having designed a new clean sheet airplane. WN drove the train on the NG from the start--Boeing should have taken that singular opportunity to thank them but tell them that their fleet commonality wasn't going to dictate much necessary airframe improvements for the 737. So then you have Frankenstein at work, with the 737-900ER, and then the MAX with shoehorning a significantly different engine on it and having to programatically compensate for aerodynamic compromise. Separate rant altogether about how Boeing's desire to placate a major customer in WN actually hurt them in the long run. And we may--*may*--be seeing the ultimate price for that now, which would be tragic.

I'm not a big fan of the MAX but how do you fault Boeing/WN for the NG when it was an incredible market success? Are you saying it would have been even more successful and profitable had they done a clean sheet back in the 90's?

With the MAX, it is what it is. Aside from what we know about the MCAS system, it doesn't seem to be an abject failure - just not the best.

Furthermore, the market dictated the development of the MAX not the other way around. It's not like Boeing went out and said, here's the max, take it or leave it. They developed what the market wanted. The market didn't want to wait for a new single aisle aircraft and it didn't want to pay the sticker price of a new single aisle aircraft.

Starlionblue wrote:

Waterbomber2 wrote:

ikramerica wrote:

But how on earth would this not have been experienced by Boeing in modeling, wind tunnel testing, regular flight testing, envelope establishment, and 2 years in service around the world?

I would still think, that even if what you are saying is correct, it has to be enhanced by some OTHER event that compounds it, some sort of malfunction.

I think that it can be explained by the fact that modelling is not advanced enough or does not take into account the air sucked in by an engine as this was not as much of a factor in previous designs.
For instance in wind tunnel testing, the engines are just static elements and don't have a fan in them that sucks in ram air.

I don't buy it. Fluid Dynamics modelling is super advanced, plus there is wind tunnel testing. IMHO there is no way this sort of thing would have been simply "missed".

32andBelow wrote:

He said half a dozen witnesses but you cut that off his quote.

downdata wrote:

Ethiopia wanted to send the flight-data and cockpit-voice recorders to the U.K.’s Air Accidents Investigation Branch to recover the data, causing U.S. investigators to hold intense behind-the-scenes talks to bring the remains to America, the Wall Street Journal reported, citing people familiar with the matter. U.S. officials wanted to have the recorders sent to the National Transportation Safety Board on grounds that American government experts would provide the most reliable and accurate data downloads, according to the report. The U.S. hadn’t received a final decision as of late Tuesday, according to the Journal.[/code]

This would be pretty much unprecedented right? Given this is a US made plane.

downdata wrote:

Per Bloomberg: Ethiopia wanted to send the flight-data and cockpit-voice recorders to the UK AAIB instead of NTSB in the US

https://www.bloomberg.com/news/articles ... emium-asia

Code: Select all

Blackbox to U.K. or U.S.? (10:58 a.m.)

Ethiopia wanted to send the flight-data and cockpit-voice recorders to the U.K.’s Air Accidents Investigation Branch to recover the data, causing U.S. investigators to hold intense behind-the-scenes talks to bring the remains to America, the Wall Street Journal reported, citing people familiar with the matter. U.S. officials wanted to have the recorders sent to the National Transportation Safety Board on grounds that American government experts would provide the most reliable and accurate data downloads, according to the report. The U.S. hadn’t received a final decision as of late Tuesday, according to the Journal.

This would be pretty much unprecedented right? Given this is a US made plane.

downdata wrote:

Per Bloomberg: Ethiopia wanted to send the flight-data and cockpit-voice recorders to the UK AAIB instead of NTSB in the US

https://www.bloomberg.com/news/articles ... emium-asia

Code: Select all

Blackbox to U.K. or U.S.? (10:58 a.m.)

Ethiopia wanted to send the flight-data and cockpit-voice recorders to the U.K.’s Air Accidents Investigation Branch to recover the data, causing U.S. investigators to hold intense behind-the-scenes talks to bring the remains to America, the Wall Street Journal reported, citing people familiar with the matter. U.S. officials wanted to have the recorders sent to the National Transportation Safety Board on grounds that American government experts would provide the most reliable and accurate data downloads, according to the report. The U.S. hadn’t received a final decision as of late Tuesday, according to the Journal.

This would be pretty much unprecedented right? Given this is a US made plane.

downdata wrote:

Per Bloomberg: Ethiopia wanted to send the flight-data and cockpit-voice recorders to the UK AAIB instead of NTSB in the US
.

hamiltondaniel wrote:

I'm going to officially proclaim myself the logic checker of this thread. Somebody needs to.

slider wrote:

trpmb6 wrote:

PlanesNTrains wrote:

I'm not a big fan of the MAX but how do you fault Boeing/WN for the NG when it was an incredible market success? Are you saying it would have been even more successful and profitable had they done a clean sheet back in the 90's?

With the MAX, it is what it is. Aside from what we know about the MCAS system, it doesn't seem to be an abject failure - just not the best.

Furthermore, the market dictated the development of the MAX not the other way around. It's not like Boeing went out and said, here's the max, take it or leave it. They developed what the market wanted. The market didn't want to wait for a new single aisle aircraft and it didn't want to pay the sticker price of a new single aisle aircraft.

I utterly disagree. They capitulated to the "market" in the sense they gave in to WN when the NG was being developed in the first place. Boeing has a history of allowing far too much latitude in carriers' ordering options. When the NG was launched, they gave in to WN for their "need" to have type commonality, and the die was cast...and it shouldn't have been. As a consequence, design took a back seat to sales--globally. And that continues today because they perpetuated an aging airframe with new engines even then.

Now, the development costs for a modified variant are obviously much less, so we all understand Boeing's approach, but it remains questionable as to whether they ought to have made a clean sheet decision even then, even considering the monster development to do so. IF--and I say this cautiously--this ET302 accident is related to the MCAS system, there are some roots to follow back and that would be even more tragic. A bridge too far, Boeing. IF that's the case.

*Sidenote....has anyone found bag data for this airplane yet? Load shift? Unlikely but a thought.

Waterbomber2 wrote:

I have a theory that could explain the AOA sensor malfunction indication and the crashes, while also explaining why MCAS is wrongly accused of being the main culprit.

If you look at the position of the engine intakes on the MAX 8, they have been brought forward and up, to maintain ground clearance despite installing a larger fan.
The MCAS system has been added to counter the balance effects compared to the -800, but let's leave this aside for a minute and focus purely on aerodynamics.
My theory is that due to the new position and size of the fan, where the fan intake's upper edge is protruding above the wing's extrados even when the aircraft is level VS. ram air, the MAX 8's engines may be too high and sucking a lot of ram air that previously came into contact with the wing to contribute to lift generation, causing the wing to locally stall prematurely. In addition, it's possible that the position of the new engines vis a vis the wings is causing ram air to become turbulent ahead of the wing and creating a shadow effect for the wing sections situated behind the engine.
Basically, my theory is that the higher position of the engine intakes is reducing the flight envelope of the MAX 8 by causing premature, undetected stalls.
In my flight training days, we would practice the powered stall recovery with the instructor and this reminds me of that phenomenon.

-it explains why the Lion Air aircraft went out of envelope in the climb after take-off: an already high angle of attack during climb, followed by a local undetected stall of the wing, which expands into a power-on stall potentially supported by flap retraction.
-The AOA sensors indicate a malfunction because they are outside preset parameters. Essentially, they are not malfunctioning, but they appear to be malfunctioning as the aircraft is in a stall but not within the expected parameters of a stall.
-The trim may be running amock and contributing to a difficult recovery, again, because it is operating outside the parameters.


Please look at the high position of the engine intakes and compare them to the -800.
They are crazy high and imagine how they will be shadowing a good portion of the wing's leading edge in a climb with a higher angle of attack.

navjotgill45 wrote:

Apologies if asked before, thread too longto check. I'm still confused as to why MCAS would even operate in an AoA disagree situation. Surely the certifiers would have considered a "faulty airpseed/AoA etc" situation? Would love to be enlightened on this by knowledgeble posters (pilots/mechanics etc.)?

2175301 wrote:

As this is an American Made Aircraft the NTSB has a right to at least be an observer to the investigation. It would be routine for them to request that they do the downloads. However, Ethiopia (or any country doing the investigation) can make their own decision on where they are downloaded, and by who. I have no problem with the UK doing this work - neither will the NTSB if that is the choice of Ethiopia.

Have a great day,

downdata wrote:

2175301 wrote:

As this is an American Made Aircraft the NTSB has a right to at least be an observer to the investigation. It would be routine for them to request that they do the downloads. However, Ethiopia (or any country doing the investigation) can make their own decision on where they are downloaded, and by who. I have no problem with the UK doing this work - neither will the NTSB if that is the choice of Ethiopia.

Have a great day,

The new reporting does say this is "causing U.S. investigators to hold intense behind-the-scenes talks to bring the remains to America, the Wall Street Journal reported", so even at the surface level, there seems to be some contention there.

spacecadet wrote:

32andBelow wrote:

He said half a dozen witnesses but you cut that off his quote.

No, he chose to quote one witness - as did Reuters. Let's see what the actual pattern is among the other witnesses when asked non-leading questions that aren't designed to get matching answers by someone not in the media.

Reefwiz wrote:

spacecadet wrote:

32andBelow wrote:

He said half a dozen witnesses but you cut that off his quote.

No, he chose to quote one witness - as did Reuters. Let's see what the actual pattern is among the other witnesses when asked non-leading questions that aren't designed to get matching answers by someone not in the media.

Just to be accurate, Reuters interviewed SIX villagers. FOUR reported seeing smoke trailing the aircraft and TWO heard metallic rattling noises in addition to seeing the smoke. Sounds to me like a hull breech by lithium batteries, compressed gas cylinders, hazardous materials or an old fashioned b0mb....probably in cargo hold.

downdata wrote:

The new reporting does say this is "causing U.S. investigators to hold intense behind-the-scenes talks to bring the remains to America, the Wall Street Journal reported", so even at the surface level, there seems to be some contention there.

MillwallSean wrote:

downdata wrote:

The new reporting does say this is "causing U.S. investigators to hold intense behind-the-scenes talks to bring the remains to America, the Wall Street Journal reported", so even at the surface level, there seems to be some contention there.

Hmm, this is getting out of control.
If we cant trust national bodys and believe that corporate interests yield to much power, then present system of certification will break down and lead to alot of complications. Not sure I am to happy with that.
Also not to sure I understand anyones motive here. The Ethiopians choose where to send it. it is their investigation and their choice.
Why would the NTSB push to bring the boxes to the US should the Ethiopians want it done in the UK. the UK is as good as the NTSB so the rationale for this would give raise to a lot of unwarranted and unnecessary speculation. Whats hidden? Whos interests are protected?
And if that's the start or the cooperation between the assisting Americans and the lead agents from Ethiopia it doesn't bode well for the investigation.

Id say a lot of the blame for this can be placed squarely on the the FAA. They have been questioned, in regards to their independence, and that might be the issue here. A belief that there is a risk for bias should it be sent to the US.
However this is the American NTSB whom I haven't heard people question in regards to competence or bias. Anyway, if this becomes a trend it doesn't bode well for the neutrality and expertise that's expected from all the worlds investigating bodies.

Touch wood this is just the media making a hen out of a feather.

tvarad wrote:

From the Ethiopian Airlines CEO through Richard Quest (their travel reporter), CNN is reporting that the airplane had flight control issues:

https://twitter.com/CNNnewsroom/status/ ... index.html

Surely the pilots would have gotten the memo on the MCAS issue after the Lion Air crash and must have tried the fix(es) so if they still couldn't fly it, there's a high probability that the loss of control points to something else.

RandallStephens wrote:

Two different witness accounts. What I like is that they're not using big words to describe what they saw, they are using plain folk speech. To me that's believable.


https://youtu.be/DnCtVuLn5iY

https://youtu.be/3A9uHGqiyUA

Does mcas make a plane burn, too?

Finn350 wrote:

RandallStephens wrote:

Two different witness accounts. What I like is that they're not using big words to describe what they saw, they are using plain folk speech. To me that's believable.


https://youtu.be/DnCtVuLn5iY

https://youtu.be/3A9uHGqiyUA

Does mcas make a plane burn, too?

"Before falling down, the plane rotated two times in the air, and it had some smoke coming from the back then, it hit the ground and and exploded."

From the translation it is not clear what he meant. I would interpret that the plane was cartwheeling in the ground, and had some smoke coming as result of the cartwheeling, and then exploded. I don't see how it could have rotated two times when still airborne.

Reefwiz wrote:

spacecadet wrote:

32andBelow wrote:

He said half a dozen witnesses but you cut that off his quote.

No, he chose to quote one witness - as did Reuters. Let's see what the actual pattern is among the other witnesses when asked non-leading questions that aren't designed to get matching answers by someone not in the media.

Just to be accurate, Reuters interviewed SIX villagers. FOUR reported seeing smoke trailing the aircraft and TWO heard metallic rattling noises in addition to seeing the smoke. Sounds to me like a hull breech by lithium batteries, compressed gas cylinders, hazardous materials or an old fashioned b0mb....probably in cargo hold.