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Amiga500
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 10:03 am

OldAeroGuy wrote:
<SNIP>


That is good information. Thanks.

OldAeroGuy wrote:
As Zeke has pointed out, the 737 QRH says don't retract the Flaps with the stick shaker active. Why did Lion Air crews and the Ethiopian crews retract the Flaps?


Without being in their head, I would suspect because of confidence in airspeed, engine thrust and inclination - furthermore at that point, the pilots did not make a wrong problem diagnosis.
 
jollo
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 10:59 am

keesje wrote:
There was an article about an ($ optional $) OAG malfunction indicator, that was standard on previous 737 versions. Can't find it back..


I'll second this question: there have been hints in the last couple of pages of this thread about a warning light which was standard in the NG but became an optional extra with the MAX. To be clear: I'm not talking about the "AoA disagree" flag and AoA indicator, which were optional both for the NG and for the MAX. So is there any warning (other than AoA disagree) that was standard in the NG but became optional with the MAX?
 
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zeke
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 11:02 am

Amiga500 wrote:
So you are trying to argue a FBW system could be assembled with single failure points all over the place - but that is fine as long as the physical connection between actuator and the control surface is redundant?


The software, wiring, and hydraulics are covered elsewhere. A FBW aircraft is certified the same way as a non FBW for that requirement, it needs to demonstrate that if a surface is jammed or failed the aircraft is still controlled.

Amiga500 wrote:
Which of course is why aircraft sometimes have to fly around to burn or dump fuel before landing if they have had to return immediately to their departure airport.


You can return to land immediately for any emergency.

Amiga500 wrote:
Yet no one does them unless in a dire time-dependent emergency. For good reason. Your putting the airframe out of action pending a C or D check (localised).
- Not worried about the engine thrust - its more structural loading through the u/c.


You can return immediately for any emergency, no such thing as a “dire time-dependent emergency”.

I am not aware of any C or D check required, we print out a Load 15 report, if the rate of descent on touchdown is within the zone nothing further is required.
Human rights lawyers are "ambulance chasers of the very worst kind.'" - Sky News
 
kalvado
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 11:15 am

IADFCO wrote:
kalvado wrote:
OldAeroGuy wrote:

And why go to the expense of chopping a 737 MAX in half when a whole one is out there flying?

Remember, the wind tunnel is static but you're looking at a dynamic condition. What you're suggesting would help in the preflight stage but would be very, very, very expensive. Once the airplane is in flight test, it's the better experimental vehicle.

More thinking about how to justify such oversize facility. One wing off model is probably on par with 75% model cost-wise -but when I think about per-hour costs involved for something like that... Instrumentation may still be better than what you can get flying... maybe..


In the 80' x 120' Ames tunnel you can definitely fit one half of a full size 737NG attaching it to a sufficiently large plate, so that no flow from the "real" half goes toward the "nonexisting" half. Probably the "half aircraft" would be turned on the side, with the wing sticking up. In doing so, however, you limit yourself to situations where the flow is symmetric with respect to the longitudinal plane of the aircraft, i.e., you cannot have any sideslip or test any nonsymmetric configurations, e.g., one with flaps deployed on just one wing.

WInd tunnel test vs flight test is not an either/or proposition. In the wind tunnel you can generate much more precise and repeatable flow conditions, and take flow measurements that would be hard or impossible to get on a flying aircraft. This could be useful, for example, to calibrate your aerodynamic prediction models. You can also test several configurations, e.g., different engine positions with respect to the wing, or separate effects, e.g., wing vs tail.

To do this you don't obviously take an aircraft off the production line and physically saw it in half, seats, wiring, and all. Every aircraft manufacturer and most aerospace research organizations have model shops that build specialized wind tunnel models.

Obvious, simple and an incorrect solution. There will be flow interaction with dividing plane, unless you make it super slippery. If you know how to achieve that, I beg you to use private message so we can think of commercial application!
Other than that, there is no guarantee that flow will be perfectly symmetric. Vortex may form somewhere, with a random rotation direction.
Last edited by kalvado on Mon Apr 29, 2019 11:16 am, edited 1 time in total.
 
jollo
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 11:16 am

I got a little lost about the proposed fix. In my understanding the gist of what Boeing submitted as a permanent solution for MCAS runaway issues is:
  • STS and MCAS automatically deactivate on an AoA disagree condition
  • MCAS authority no longer unlimited (one activation cycle per "high AoA event" + new limit on AND input per cycle?)
  • in AoA disagree conditions, pilots will get a "SPEED TRIM FAIL" warning light, and will be directed to do the Unreliable Airspeed NNC
  • no sim training required

Did I get it right or am I oversimplifying things?
 
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keesje
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 11:22 am

jollo wrote:
keesje wrote:
There was an article about an ($ optional $) OAG malfunction indicator, that was standard on previous 737 versions. Can't find it back..


I'll second this question: there have been hints in the last couple of pages of this thread about a warning light which was standard in the NG but became an optional extra with the MAX. To be clear: I'm not talking about the "AoA disagree" flag and AoA indicator, which were optional both for the NG and for the MAX. So is there any warning (other than AoA disagree) that was standard in the NG but became optional with the MAX?


This WSJ article is pay walled.

https://www.wsj.com/articles/boeings-enduring-puzzle-why-certain-safety-features-on-737-max-jets-were-turned-off-11556456400

CNBC has more. Apparently from a whistleblower.
https://www.cnbc.com/2019/04/28/boeing-didnt-tell-southwest-that-safety-feature-on-737-max-was-turned-off-wsj.html

Southwest Airline’s statement:

Upon delivery (prior to the Lion Air event), the AOA Disagree lights were depicted to us by Boeing as operable on all MAX aircraft, regardless of the selection of optional AOA Indicators on the Primary Flight Display (PFD).

The manual documentation presented by Boeing at Southwest’s MAX entry into service indicated the AOA Disagree Light functioned on the aircraft, similar to the Lights on our NG series.

After the Lion Air event, Boeing notified us that the AOA Disagree Lights were inoperable without the optional AOA Indicators on the MAX aircraft.

At that time, Southwest installed the AOA Indicators on the PFD, resulting in the activation of the AOA Disagree lights - both items now serve as an additional crosscheck on all MAX aircraft.


The FAA considered grounding the aircraft at that stage. Which, as we know now, happened only after the second crash / ROW did.

The FAA even considered grounding Southwest’s Max fleet while they weighed whether or not the airline’s pilots needed additional training about the safety alert, according to the Journal. But those discussions were brief and did not go up the chain, the newspaper reported.


Another depth charge if you ask me.
"Never mistake motion for action." Ernest Hemingway
 
CO953
Posts: 523
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 11:33 am

GalaxyFlyer wrote:
smartplane wrote:
ltbewr wrote:
There needs to be better grooming and training of pilots, less expensive to learn how to become a pilot, better pay for pilots in their early years and on smaller 'commuter' airlines. It is not very good to pay someone flying humans more like in term of real time working for a pay rate like a worker at McDonald's. If they are smart and good enough to be pilots they will look to areas of work that pay better up front, allow them to afford to pay off loans and don't have the responsibility of flying.

Agreed.

OEM's need to ensure they test aircraft initially with test pilots, and then real pilots with different proficiency levels.

Perhaps a future feature for passengers selecting a flight, will be the ability to check crew experience based on training and hours on type. If below a certain threshold, the ability to cancel and re-book at no extra cost.


Charter operators are already doing that kind of background check. When my schedulers booked a charter (corporate operator needing lift), they would present me with a brief on the crew’s licensing and flight experience, aircraft status. If the crew didn’t meet our standards, I’d approve a waiver or disapprove the crew and ask the operator to change crew or rebook the charter. The most frequent red flag was a high experience captain and newly rated co-pilot. I’d call, verify it was a FO in training with an instructor.

There’s no dangerous planes, no dangerous pilots, no dangerous weather. There’s only dangerous operations. A Cub can just barely kill you, Bob Hoover crashed a plane having not checked the tanks had the proper fuel and thunderstorms have been safely penetrated. The more hysterical here, ten years on, will be flying MAXs without a thought especially, if the choice is driving for days or swimming.


gf


Off-topic, but I feel I should reply, on Mr. Hoover's behalf. I spent a lot of time with him over an 8-year period and he told me how this went down. I think it's a mischaracterization to hang the refueling error on Bob, if that's how the comment was meant. A very young guy put the wrong fuel in Bob's tanks. He was in tears after the accident & Bob forgave him and asked that he not be fired, and next time Bob came through that airport, he made sure to have the same young guy be the one to refuel his plane. That's how Bob was. This resulted in the "Hoover Nozzle" and the "Hoover Ring." sort of like the restrictor that was placed in automotive fuel-tank filler-necks during the transition from leaded gaoline to unleaded gasoline, to prevent the larger "leaded" nozzles from being inserted into tanks meant to be filled with unleaded fuel.
--------------------------
From wiki:
Hoover Nozzle and Hoover Ring

The "Hoover Nozzle", used on jet fuel pumps, is designed with a flattened bell shape. It cannot be inserted in the filler neck of a gasoline-powered aircraft with the "Hoover Ring" installed, thus preventing the tank from accidentally being filled with jet fuel.

This system was given this name following an accident in which Hoover was seriously injured, when both engines on his Shrike Commander failed during takeoff. Investigators found that the plane had just been fueled by line personnel who mistook the piston-engine Shrike for a similar turboprop model, filling the tanks with jet fuel instead of avgas (aviation gasoline).[45] There was enough avgas in the fuel system to taxi to the runway and take off, but then the jet fuel was drawn into the engines, causing them to stop.

Once Hoover recovered, he widely promoted[46] the use of the new type of nozzle with the support and funding of the National Air Transportation Association, General Aviation Manufacturers Association, and various other aviation groups. The nozzle is now required by federal government regulation on jet fuel pumps.[
 
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SomebodyInTLS
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 11:54 am

jollo wrote:
keesje wrote:
There was an article about an ($ optional $) OAG malfunction indicator, that was standard on previous 737 versions. Can't find it back..


I'll second this question: there have been hints in the last couple of pages of this thread about a warning light which was standard in the NG but became an optional extra with the MAX. To be clear: I'm not talking about the "AoA disagree" flag and AoA indicator, which were optional both for the NG and for the MAX. So is there any warning (other than AoA disagree) that was standard in the NG but became optional with the MAX?


My impression from the article (it was a couple of pages back in the thread: https://www.businessinsider.com/boeing-737-max-safety-features-disable-southwest-grounding-discussions-2019-4?r=US&IR=T) is that the journalist is probably actually referring to AoA disagree but never names it.
"As with most things related to aircraft design, it's all about the trade-offs and much more nuanced than A.net likes to make out."
 
jollo
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 12:33 pm

keesje wrote:


SomebodyInTLS wrote:
My impression from the article (it was a couple of pages back in the thread: https://www.businessinsider.com/boeing-737-max-safety-features-disable-southwest-grounding-discussions-2019-4?r=US&IR=T) is that the journalist is probably actually referring to AoA disagree but never names it.


Thanks a lot for the links. My takeaway is:
  1. this is still all about the AoA disagree warning light
  2. the articles wording convey the meaning that the AoA disagree warning was available on the NG ("... was included in previous versions of the 737 ...", "... a safety feature found on earlier models ..."), but never affirm that such warning was standard on the NG.

I checked a couple of old 737 QRHs from 2013 and 2014 available online, and AOA DISAGREE is indeed included as a NNC; however, QRH is a delivery-specific document and these references could refer to clients having purchased non-standard options (i.e. all of them).

So can anyone in the know give a definitive answer as to whether the AoA disagree warning was standard on the NG, or was a client-specific option (as on the MAX)?
 
Interested
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 12:55 pm

jollo wrote:
keesje wrote:


SomebodyInTLS wrote:
My impression from the article (it was a couple of pages back in the thread: https://www.businessinsider.com/boeing-737-max-safety-features-disable-southwest-grounding-discussions-2019-4?r=US&IR=T) is that the journalist is probably actually referring to AoA disagree but never names it.


Thanks a lot for the links. My takeaway is:
  1. this is still all about the AoA disagree warning light
  2. the articles wording convey the meaning that the AoA disagree warning was available on the NG ("... was included in previous versions of the 737 ...", "... a safety feature found on earlier models ..."), but never affirm that such warning was standard on the NG.

I checked a couple of old 737 QRHs from 2013 and 2014 available online, and AOA DISAGREE is indeed included as a NNC; however, QRH is a delivery-specific document and these references could refer to clients having purchased non-standard options (i.e. all of them).

So can anyone in the know give a definitive answer as to whether the AoA disagree warning was standard on the NG, or was a client-specific option (as on the MAX)?


The article does suggest that some warning that was standard on the NG was disabled on Max planes in 2017 without informing FAA or the airlines
 
patches
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 1:22 pm

Dont know if this question has been asked but here goes. What world happen to Boeing and the Max if a few months in to flying again a Max goes down in the US. Could be related to software or any other issue. pilot error or weather.
 
AirwayBill
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 1:27 pm

[threeid][/threeid]
The article does suggest that some warning that was standard on the NG was disabled on Max planes in 2017 without informing FAA or the airlines


Worse than that!

Upon delivery (prior to the Lion Air event), the AOA Disagree lights were depicted to us by Boeing as operable on all MAX aircraft
...
After the Lion Air event, Boeing notified us that the AOA Disagree Lights were inoperable without the optional AOA Indicators on the MAX aircraft


If true I would call this organized, high level fraud, no more, no less.
Last edited by AirwayBill on Mon Apr 29, 2019 1:44 pm, edited 1 time in total.
 
XRAYretired
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 1:34 pm

jollo wrote:
I got a little lost about the proposed fix. In my understanding the gist of what Boeing submitted as a permanent solution for MCAS runaway issues is:
  • STS and MCAS automatically deactivate on an AoA disagree condition
  • MCAS authority no longer unlimited (one activation cycle per "high AoA event" + new limit on AND input per cycle?)
  • in AoA disagree conditions, pilots will get a "SPEED TRIM FAIL" warning light, and will be directed to do the Unreliable Airspeed NNC
  • no sim training required

Did I get it right or am I oversimplifying things?


The Southwest notice has confused the issue. It mixes references to STS and MCAS so it no longer adequately reflects the previously published MCAS fix description.

I hope the pilots can understand it.


Ray
 
Oykie
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 1:50 pm

Doe anyone here know when the airlines will start fixing the airplanes? Boeing has finished flight tests and are waiting for the approval to be fixed. Do airlines have to wait until the grounding is lifted, or can they start implementing the fix while the fleet is grounded?

PS: I am really pleased with the Add foe for this thread. I have never considered that before, but after adding a few users, I have been able to get more insightful updates reading here. A few members seem more interested in arguing, than enlightening.
Dream no small dream; it lacks magic. Dream large, then go make that dream real - Donald Douglas
 
IADFCO
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 2:06 pm

kalvado wrote:
IADFCO wrote:
kalvado wrote:
More thinking about how to justify such oversize facility. One wing off model is probably on par with 75% model cost-wise -but when I think about per-hour costs involved for something like that... Instrumentation may still be better than what you can get flying... maybe..


In the 80' x 120' Ames tunnel you can definitely fit one half of a full size 737NG attaching it to a sufficiently large plate, so that no flow from the "real" half goes toward the "nonexisting" half. Probably the "half aircraft" would be turned on the side, with the wing sticking up. In doing so, however, you limit yourself to situations where the flow is symmetric with respect to the longitudinal plane of the aircraft, i.e., you cannot have any sideslip or test any nonsymmetric configurations, e.g., one with flaps deployed on just one wing.

WInd tunnel test vs flight test is not an either/or proposition. In the wind tunnel you can generate much more precise and repeatable flow conditions, and take flow measurements that would be hard or impossible to get on a flying aircraft. This could be useful, for example, to calibrate your aerodynamic prediction models. You can also test several configurations, e.g., different engine positions with respect to the wing, or separate effects, e.g., wing vs tail.

To do this you don't obviously take an aircraft off the production line and physically saw it in half, seats, wiring, and all. Every aircraft manufacturer and most aerospace research organizations have model shops that build specialized wind tunnel models.

Obvious, simple and an incorrect solution. There will be flow interaction with dividing plane, unless you make it super slippery. If you know how to achieve that, I beg you to use private message so we can think of commercial application!
Other than that, there is no guarantee that flow will be perfectly symmetric. Vortex may form somewhere, with a random rotation direction.


Google "semi span wind tunnel testing" for additional information, including technical papers, and lots of pictures.
 
jollo
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 2:18 pm

Interested wrote:
jollo wrote:
keesje wrote:


SomebodyInTLS wrote:
My impression from the article (it was a couple of pages back in the thread: https://www.businessinsider.com/boeing-737-max-safety-features-disable-southwest-grounding-discussions-2019-4?r=US&IR=T) is that the journalist is probably actually referring to AoA disagree but never names it.


Thanks a lot for the links. My takeaway is:
  1. this is still all about the AoA disagree warning light
  2. the articles wording convey the meaning that the AoA disagree warning was available on the NG ("... was included in previous versions of the 737 ...", "... a safety feature found on earlier models ..."), but never affirm that such warning was standard on the NG.

I checked a couple of old 737 QRHs from 2013 and 2014 available online, and AOA DISAGREE is indeed included as a NNC; however, QRH is a delivery-specific document and these references could refer to clients having purchased non-standard options (i.e. all of them).

So can anyone in the know give a definitive answer as to whether the AoA disagree warning was standard on the NG, or was a client-specific option (as on the MAX)?


The article does suggest that some warning that was standard on the NG was disabled on Max planes in 2017 without informing FAA or the airlines


Agreed, it does suggest that, but stops short of affirming that the AoA warning light was standard on the NG (i.e. the journo does not have a source to back him up just in case...). However it would take only one informed a.net member (i.e. a pilot currently flying the NG) to say "hey, I don't have any AOA DISAGREE warning light in my cockpit (and my QRH doesn't mention it either)" to prove that AoA disagree was an optional extra for the NG too. The opposite proof would be quite a bit more challenging.
 
kalvado
Posts: 2896
Joined: Wed Mar 01, 2006 4:29 am

Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 2:23 pm

IADFCO wrote:
kalvado wrote:
IADFCO wrote:

In the 80' x 120' Ames tunnel you can definitely fit one half of a full size 737NG attaching it to a sufficiently large plate, so that no flow from the "real" half goes toward the "nonexisting" half. Probably the "half aircraft" would be turned on the side, with the wing sticking up. In doing so, however, you limit yourself to situations where the flow is symmetric with respect to the longitudinal plane of the aircraft, i.e., you cannot have any sideslip or test any nonsymmetric configurations, e.g., one with flaps deployed on just one wing.

WInd tunnel test vs flight test is not an either/or proposition. In the wind tunnel you can generate much more precise and repeatable flow conditions, and take flow measurements that would be hard or impossible to get on a flying aircraft. This could be useful, for example, to calibrate your aerodynamic prediction models. You can also test several configurations, e.g., different engine positions with respect to the wing, or separate effects, e.g., wing vs tail.

To do this you don't obviously take an aircraft off the production line and physically saw it in half, seats, wiring, and all. Every aircraft manufacturer and most aerospace research organizations have model shops that build specialized wind tunnel models.

Obvious, simple and an incorrect solution. There will be flow interaction with dividing plane, unless you make it super slippery. If you know how to achieve that, I beg you to use private message so we can think of commercial application!
Other than that, there is no guarantee that flow will be perfectly symmetric. Vortex may form somewhere, with a random rotation direction.


Google "semi span wind tunnel testing" for additional information, including technical papers, and lots of pictures.


And then spend quite a bit of time understanding the role of the boundary effects. what I see, as expected, is that gap can play significant role. Would that end up more accurate than 75% scale model?
I understand @oldaeroguy's point that once you have a plane in the air, it may be the most efficient way of doing things. It is not even counterintuitive once you think about cost of operating huge unique setup.
 
jollo
Posts: 396
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 2:33 pm

XRAYretired wrote:
jollo wrote:
I got a little lost about the proposed fix. In my understanding the gist of what Boeing submitted as a permanent solution for MCAS runaway issues is:
  • STS and MCAS automatically deactivate on an AoA disagree condition
  • MCAS authority no longer unlimited (one activation cycle per "high AoA event" + new limit on AND input per cycle?)
  • in AoA disagree conditions, pilots will get a "SPEED TRIM FAIL" warning light, and will be directed to do the Unreliable Airspeed NNC
  • no sim training required

Did I get it right or am I oversimplifying things?


The Southwest notice has confused the issue. It mixes references to STS and MCAS so it no longer adequately reflects the previously published MCAS fix description.

I hope the pilots can understand it.


Ray


Ok, fair enough. Then I am still confused by the "previously published MCAS fix description", specifically when it comes to what happens in an AoA disagree condition. I get that MCAS v2 will be automatically disabled somehow (welcome to automation 101), but what warning will be presented to the pilots? What will be the prescribed procedure in response? Apologies if this was already discussed (it it wasn't, IMO discussing when the MAX will return to service is quite premature).
 
OldAeroGuy
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 2:36 pm

keesje wrote:
Stick shaker -> stall, IAS 250 kts, TOGA, but don't retract the flaps (with their nose down moment) while fighting unexplained nose down forces! .. yeah.. If an airlines average pilots aren't good enough to fly that aircraft, they better don't buy such aircraft.


Please go back and review the JT610 and ET302 FDR traces. MCAS is only active when Flaps are retracted.

Before the Flaps are retracted, there were no "unexpected nose down forces". Retracting Flaps with an active stick shaker is contrary to Boeing operational procedures.

If either JT610 and ET302 had left Flaps extended per Boeing procedure for an active stick shaker with Flaps extended and returned to land, neither airplane would have crashed.
Last edited by OldAeroGuy on Mon Apr 29, 2019 2:53 pm, edited 2 times in total.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
OldAeroGuy
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 2:48 pm

jollo wrote:
Ok, fair enough. Then I am still confused by the "previously published MCAS fix description", specifically when it comes to what happens in an AoA disagree condition. I get that MCAS v2 will be automatically disabled somehow (welcome to automation 101), but what warning will be presented to the pilots? What will be the prescribed procedure in response? Apologies if this was already discussed (it it wasn't, IMO discussing when the MAX will return to service is quite premature).


As I understand MCAS.v2, it will have a visual display of "AOA Disagree"

If this is displayed, MCAS will be disabled so I suspect no additional pilot action will be necessary except the usual one of avoiding high AoA.
Last edited by OldAeroGuy on Mon Apr 29, 2019 3:07 pm, edited 1 time in total.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
XRAYretired
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 2:53 pm

jollo wrote:
XRAYretired wrote:
jollo wrote:
I got a little lost about the proposed fix. In my understanding the gist of what Boeing submitted as a permanent solution for MCAS runaway issues is:
  • STS and MCAS automatically deactivate on an AoA disagree condition
  • MCAS authority no longer unlimited (one activation cycle per "high AoA event" + new limit on AND input per cycle?)
  • in AoA disagree conditions, pilots will get a "SPEED TRIM FAIL" warning light, and will be directed to do the Unreliable Airspeed NNC
  • no sim training required

Did I get it right or am I oversimplifying things?


The Southwest notice has confused the issue. It mixes references to STS and MCAS so it no longer adequately reflects the previously published MCAS fix description.

I hope the pilots can understand it.


Ray


Ok, fair enough. Then I am still confused by the "previously published MCAS fix description", specifically when it comes to what happens in an AoA disagree condition. I get that MCAS v2 will be automatically disabled somehow (welcome to automation 101), but what warning will be presented to the pilots? What will be the prescribed procedure in response? Apologies if this was already discussed (it it wasn't, IMO discussing when the MAX will return to service is quite premature).

OK. This is the published material, my notes in normal font to try and answer the question.

-Flight control system will now compare inputs from both AOA sensors. If the sensors disagree by 5.5 degrees or more with the flaps retracted, MCAS will not activate. [i]The two sensor signals will be compared and if the difference is >5.5 deg, AOA DISAGREE Flag will be set. MCAS will check for the flag before it initiates and if present, it will not do so.
-An indicator on the flight deck display will alert the pilots to AoA Disagree. I would assume that an AOA Disagree QRH will be required
-If MCAS is activated in non-normal conditions, it will only provide one input for each elevated AOA event. I understand the trigger will be the transition from below to above a set value, so if one or both the AOA signals is failed high above the set limit, it will only be triggered once
-There are no known or envisioned failure conditions where MCAS will provide multiple inputs.
-MCAS can never command more stabilizer input than can be counteracted by the flight crew pulling back on the column.
-The pilots will continue to always have the ability to override MCAS and manually control the airplane.
[/i]

Ray
 
morrisond
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 3:19 pm

Mullenburg is answering questions live on CNBC right now
 
User avatar
keesje
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 3:30 pm

OldAeroGuy wrote:
keesje wrote:
Stick shaker -> stall, IAS 250 kts, TOGA, but don't retract the flaps (with their nose down moment) while fighting unexplained nose down forces! .. yeah.. If an airlines average pilots aren't good enough to fly that aircraft, they better don't buy such aircraft.


Please go back and review the JT610 and ET302 FDR traces. MCAS is only active when Flaps are retracted.

Before the Flaps are retracted, there were no "unexpected nose down forces". Retracting Flaps with an active stick shaker is contrary to Boeing operational procedures.

If either JT610 and ET302 had left Flaps extended per Boeing procedure for an active stick shaker with Flaps extended and returned to land, neither airplane would have crashed.


Flaps extended at 250 kts? I'm no 737 pilot, but >200 kts seems on the high side..

Boeing hopefully understands, that smart communication tactics, perception management, blame sharing and diversion worked when they together with the FAA were in charge on modifications, AD's, certifications, legal acceptance. It worked for image, credibility and stock value. Things have changed. Other people that less embedded, might get even more suspicious & formal. Which won't help quick return to service.
"Never mistake motion for action." Ernest Hemingway
 
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7BOEING7
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 3:31 pm

jollo wrote:
Interested wrote:
jollo wrote:



Thanks a lot for the links. My takeaway is:
  1. this is still all about the AoA disagree warning light
  2. the articles wording convey the meaning that the AoA disagree warning was available on the NG ("... was included in previous versions of the 737 ...", "... a safety feature found on earlier models ..."), but never affirm that such warning was standard on the NG.

I checked a couple of old 737 QRHs from 2013 and 2014 available online, and AOA DISAGREE is indeed included as a NNC; however, QRH is a delivery-specific document and these references could refer to clients having purchased non-standard options (i.e. all of them).

So can anyone in the know give a definitive answer as to whether the AoA disagree warning was standard on the NG, or was a client-specific option (as on the MAX)?


The article does suggest that some warning that was standard on the NG was disabled on Max planes in 2017 without informing FAA or the airlines


Agreed, it does suggest that, but stops short of affirming that the AoA warning light was standard on the NG (i.e. the journo does not have a source to back him up just in case...). However it would take only one informed a.net member (i.e. a pilot currently flying the NG) to say "hey, I don't have any AOA DISAGREE warning light in my cockpit (and my QRH doesn't mention it either)" to prove that AoA disagree was an optional extra for the NG too. The opposite proof would be quite a bit more challenging.


From what I have available it appears the AOA DISAGREE was standard on the NG, however it is an amber "Alert" (not warning) on the Mach Airspeed Indicator or the PFD (Primary Flight Display) and when you go to then QRH it only tells the pilots they may have an IAS DISAGREE or ALTIMETER DISAGREE alert -- there are no specific proceedures to carry out.

Whether it was installed or not would have made no difference to the outcome of the Ethiopian or Lion Air flights -- the flight crews knew they had "disagreements".
 
morrisond
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 3:32 pm

morrisond wrote:
Mullenburg is answering questions live on CNBC right now


He is sticking with the chain of events narrative - MCAS wasn't flawed and was sufficient assuming the Pilots could follow the checklists and the design did not violate any internal Boeing Guidelines or Certification Standards.
 
Interested
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 3:37 pm

morrisond wrote:
Mullenburg is answering questions live on CNBC right now


Thanks

Just watched it. He couldn't get out of there quick enough could he??

3 times he was asked by different journalists to admit Boeing made mistakes or flaws in design

3 time he refused to agree and instead repeated that the crashes were caused by a chain of events

He also stated that Boeing followed the correct certification processes etc that have worked in the past.

The final question was from the Seattle Times Guy. Who had a bit of anger in his voice by this stage. The journalist said regardless of whether you followed the certification process or not can you at least admit that your engineers created a flawed design ?

He again answered by chain of events and that Boeing are committed to improving airline safety ongoing.

It wasn't good and he was in a big rush to get off the microphone. There were lots more journalists wanting to ask questions and shouting questions at him as he left. This is a huge company with shareholders etc not answering questions.

This isn't the way to regain trust IMO

It's the exact opposite of his initial statement saying "we own this" a couple of weeks ago

Which IMO was a good statement and a good start to regain trust

Boeing have reneged on that already??
Last edited by Interested on Mon Apr 29, 2019 3:46 pm, edited 2 times in total.
 
Interested
Posts: 887
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 3:41 pm

morrisond wrote:
morrisond wrote:
Mullenburg is answering questions live on CNBC right now


He is sticking with the chain of events narrative - MCAS wasn't flawed and was sufficient assuming the Pilots could follow the checklists and the design did not violate any internal Boeing Guidelines or Certification Standards.


Yes. But he didn't convince any of those asking the questions did he. He ended up with a pretty aggressive crowd as he left.

When you want to get people onside surely you answer as many questions as they want to ask.

This was a CEO running scared.

He's not re-assured anybody with that performance

He was also asked if he was going to resign. His answer was that it's his intent to lead.
Last edited by Interested on Mon Apr 29, 2019 3:50 pm, edited 2 times in total.
 
hivue
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 3:42 pm

XRAYretired wrote:
he Southwest notice has confused the issue. It mixes references to STS and MCAS so it no longer adequately reflects the previously published MCAS fix description.

I hope the pilots can understand it.


Ray


I believe that MCAS is implemented as an extension of STS.
"You're sitting. In a chair. In the SKY!!" ~ Louis C.K.
 
OldAeroGuy
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 3:55 pm

keesje wrote:
OldAeroGuy wrote:
keesje wrote:
Stick shaker -> stall, IAS 250 kts, TOGA, but don't retract the flaps (with their nose down moment) while fighting unexplained nose down forces! .. yeah.. If an airlines average pilots aren't good enough to fly that aircraft, they better don't buy such aircraft.


Please go back and review the JT610 and ET302 FDR traces. MCAS is only active when Flaps are retracted.

Before the Flaps are retracted, there were no "unexpected nose down forces". Retracting Flaps with an active stick shaker is contrary to Boeing operational procedures.

If either JT610 and ET302 had left Flaps extended per Boeing procedure for an active stick shaker with Flaps extended and returned to land, neither airplane would have crashed.


Flaps extended at 250 kts? I'm no 737 pilot, but >200 kts seems on the high side..

Boeing hopefully understands, that smart communication tactics, perception management, blame sharing and diversion worked when they together with the FAA were in charge on modifications, AD's, certifications, legal acceptance. It worked for image, credibility and stock value. Things have changed. Other people that less embedded, might get even more suspicious & formal. Which won't help quick return to service.


Neither airplane needed to be at 250 KIAS with the Flaps extended. For ET302, stick shaker started at 150 kts. and the Flaps 5 placard is 250 KIAS. Both crews had control over speed by either changing their climb angle or reducing thrust.

A good starting point would have been to do the Flaps down "Airspeed Unreliable" QRH procedure: 80% N1 and 10 deg pitch attitude. There was never a need to retract the Flaps.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
Interested
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 3:56 pm

 
User avatar
7BOEING7
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 4:11 pm

OldAeroGuy wrote:
keesje wrote:
OldAeroGuy wrote:

Please go back and review the JT610 and ET302 FDR traces. MCAS is only active when Flaps are retracted.

Before the Flaps are retracted, there were no "unexpected nose down forces". Retracting Flaps with an active stick shaker is contrary to Boeing operational procedures.

If either JT610 and ET302 had left Flaps extended per Boeing procedure for an active stick shaker with Flaps extended and returned to land, neither airplane would have crashed.


Flaps extended at 250 kts? I'm no 737 pilot, but >200 kts seems on the high side..
.


Neither airplane needed to be at 250 KIAS with the Flaps extended. For ET302, stick shaker started at 150 kts. and the Flaps 5 placard is 250 KIAS. Both crews had control over speed by either changing their climb angle or reducing thrust.

A good starting point would have been to do the Flaps down "Airspeed Unreliable" QRH procedure: 80% N1 and 10 deg pitch attitude. There was never a need to retract the Flaps.


:checkmark:

First Flaps 1 thru 5 limit is 250 kts.

And one of the memory items (there aren't that many) on the Airspeed Unreliable checklist is to cross check the MACH/Airspeed indicators at which point they would have probably found the Standby and the Copilots were in agreement and "made sense", Captain goes cross cockpit or turns it over to the copilot, exercise over RTB.
 
kalvado
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 4:11 pm

OldAeroGuy wrote:
keesje wrote:
OldAeroGuy wrote:

Please go back and review the JT610 and ET302 FDR traces. MCAS is only active when Flaps are retracted.

Before the Flaps are retracted, there were no "unexpected nose down forces". Retracting Flaps with an active stick shaker is contrary to Boeing operational procedures.

If either JT610 and ET302 had left Flaps extended per Boeing procedure for an active stick shaker with Flaps extended and returned to land, neither airplane would have crashed.


Flaps extended at 250 kts? I'm no 737 pilot, but >200 kts seems on the high side..

Boeing hopefully understands, that smart communication tactics, perception management, blame sharing and diversion worked when they together with the FAA were in charge on modifications, AD's, certifications, legal acceptance. It worked for image, credibility and stock value. Things have changed. Other people that less embedded, might get even more suspicious & formal. Which won't help quick return to service.


Neither airplane needed to be at 250 KIAS with the Flaps extended. For ET302, stick shaker started at 150 kts. and the Flaps 5 placard is 250 KIAS. Both crews had control over speed by either changing their climb angle or reducing thrust.

A good starting point would have been to do the Flaps down "Airspeed Unreliable" QRH procedure: 80% N1 and 10 deg pitch attitude. There was never a need to retract the Flaps.

I tried to bring it up before.. These are ballpark conditions for maintaining altitude. There is something specific in ET situation: hot and high airport with nearby mountains. Would those recommended conditions allow a safe climb above terrain? Yes, engine out performance should be such that they can get above mountains with reduced thrust - but would a handicap of extended gear and flaps outweigh that performance of extra engine?
 
XRAYretired
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 4:19 pm

hivue wrote:
XRAYretired wrote:
he Southwest notice has confused the issue. It mixes references to STS and MCAS so it no longer adequately reflects the previously published MCAS fix description.

I hope the pilots can understand it.


Ray


I believe that MCAS is implemented as an extension of STS.


Boeing fix desription is entirely in terms of MCAS. Southwest have confused it by swallowing the STS line most likely.

Ray
 
art
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 4:20 pm

I heard a little of what the Boeing representative said. He maintained that the primary consideration was always safety. If that were true the company would have redesigned the wingbox (or whatever) to avoid pushing the engines forward and up on the successor to NG, Or gone for NSA.

Which was not done because Boeing's secondary consideration was safety. Their primary consideration was maintaining market share by producing an A320NEO competitor ASAP..
 
Interested
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 4:33 pm

art wrote:
I heard a little of what the Boeing representative said. He maintained that the primary consideration was always safety. If that were true the company would have redesigned the wingbox (or whatever) to avoid pushing the engines forward and up on the successor to NG, Or gone for NSA.

Which was not done because Boeing's secondary consideration was safety. Their primary consideration was maintaining market share by producing an A320NEO competitor ASAP..


Near the end he actually said "we are going to make this plane EVEN safer"

Im not sure how the word EVEN made it into that sentence but he definitely said it!
Last edited by Interested on Mon Apr 29, 2019 4:40 pm, edited 1 time in total.
 
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SuperGee
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 4:36 pm

"Boeing shareholder meeting turns tense amid 737 Max crisis"

https://www.cnn.com/2019/04/29/investin ... index.html
 
morrisond
Posts: 2772
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 4:42 pm

kalvado wrote:
OldAeroGuy wrote:
keesje wrote:

Flaps extended at 250 kts? I'm no 737 pilot, but >200 kts seems on the high side..

Boeing hopefully understands, that smart communication tactics, perception management, blame sharing and diversion worked when they together with the FAA were in charge on modifications, AD's, certifications, legal acceptance. It worked for image, credibility and stock value. Things have changed. Other people that less embedded, might get even more suspicious & formal. Which won't help quick return to service.


Neither airplane needed to be at 250 KIAS with the Flaps extended. For ET302, stick shaker started at 150 kts. and the Flaps 5 placard is 250 KIAS. Both crews had control over speed by either changing their climb angle or reducing thrust.

A good starting point would have been to do the Flaps down "Airspeed Unreliable" QRH procedure: 80% N1 and 10 deg pitch attitude. There was never a need to retract the Flaps.

I tried to bring it up before.. These are ballpark conditions for maintaining altitude. There is something specific in ET situation: hot and high airport with nearby mountains. Would those recommended conditions allow a safe climb above terrain? Yes, engine out performance should be such that they can get above mountains with reduced thrust - but would a handicap of extended gear and flaps outweigh that performance of extra engine?


Yes apparently they are sufficient for all situations - at lower altitudes (assume under 20,000') it will produce a climb.

One thing not talked about much on this website but came from the Flight Global article is that they never deviated from Take Off thrust. Apparently that is different from Climb thrust and they did not even adjust down to this value.

94% would have have been the computed take-off thrust - what would climb thrust been?
 
BravoOne
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 4:45 pm

jollo wrote:
keesje wrote:
There was an article about an ($ optional $) OAG malfunction indicator, that was standard on previous 737 versions. Can't find it back..


I'll second this question: there have been hints in the last couple of pages of this thread about a warning light which was standard in the NG but became an optional extra with the MAX. To be clear: I'm not talking about the "AoA disagree" flag and AoA indicator, which were optional both for the NG and for the MAX. So is there any warning (other than AoA disagree) that was standard in the NG but became optional with the MAX?



I see nothing in the Boeing documents that supports this line of thinking. I'll keep looking but I would not get two wrapped up in this issue.
 
oschkosch
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 4:45 pm

Interested wrote:
https://mobile.twitter.com/AlexInAir/status/1122890595192778753?ref_src=twsrc%5Egoogle%7Ctwcamp%5Eserp%7Ctwgr%5Etweet

Press conference is here
lol! He won't be around for much longer is my key takeaway from that press conference.

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A3801000
Posts: 562
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 4:52 pm

journalists who asked the questions were picked in advanced without the others knowing.
 
Interested
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 4:54 pm

BravoOne wrote:
jollo wrote:
keesje wrote:
There was an article about an ($ optional $) OAG malfunction indicator, that was standard on previous 737 versions. Can't find it back..


I'll second this question: there have been hints in the last couple of pages of this thread about a warning light which was standard in the NG but became an optional extra with the MAX. To be clear: I'm not talking about the "AoA disagree" flag and AoA indicator, which were optional both for the NG and for the MAX. So is there any warning (other than AoA disagree) that was standard in the NG but became optional with the MAX?



I see nothing in the Boeing documents that supports this line of thinking. I'll keep looking but I would not get two wrapped up in this issue.


The Wall Street Journal article said that Boeing have still not answered why they turned off the the AOA disagree feature without informing customers.

The Journal has also had sight of internal emails about this issues between FAA officials - one of whom wrote:

"It would be irresponsible to have MAX aircraft operating with AOA Disagree Warning system inoperative"

And they discussed grounding the planes until it was fixed

The concerns were then dismissed higher up the chain.

In today's press conference the CEO said these warnings would now be standard at Boeing's expense and will be retro-fitted on every MAX plane
 
Interested
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 4:57 pm

A3801000 wrote:
journalists who asked the questions were picked in advanced without the others knowing.


I think in 15 minutes there were just 4 short questions asked followed by long prepared answers from the CEO that he must have been practising a lot lately!!
 
Interested
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 4:59 pm

Interested wrote:
BravoOne wrote:
jollo wrote:

I'll second this question: there have been hints in the last couple of pages of this thread about a warning light which was standard in the NG but became an optional extra with the MAX. To be clear: I'm not talking about the "AoA disagree" flag and AoA indicator, which were optional both for the NG and for the MAX. So is there any warning (other than AoA disagree) that was standard in the NG but became optional with the MAX?



I see nothing in the Boeing documents that supports this line of thinking. I'll keep looking but I would not get two wrapped up in this issue.


The Wall Street Journal article said that Boeing have still not answered why they turned off the the AOA disagree feature without informing customers.

The Journal has also had sight of internal emails about this issues between FAA officials - one of whom wrote:

"It would be irresponsible to have MAX aircraft operating with AOA Disagree Warning system inoperative"

And they discussed grounding the planes until it was fixed

The concerns were then dismissed higher up the chain.

In today's press conference the CEO said these warnings would now be standard at Boeing's expense and will be retro-fitted on every MAX plane


In the press conference the CEO said even without the warning lights the pilots had all the information they needed to fly the plane. And that pilots need things like altitude and speed info to fly planes and they were all part of what was on screens to allow them to fly the MAX safely. And that the warning lights aren't necessary etc etc etc

He had an answer for every mistake

He's even better than Morisson!!
 
MSPNWA
Posts: 3698
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 5:06 pm

art wrote:
I heard a little of what the Boeing representative said. He maintained that the primary consideration was always safety. If that were true the company would have redesigned the wingbox (or whatever) to avoid pushing the engines forward and up on the successor to NG, Or gone for NSA.

Which was not done because Boeing's secondary consideration was safety. Their primary consideration was maintaining market share by producing an A320NEO competitor ASAP..


Insider hint (not): Safety is always in a balance with other factors. One can say it's #1, but in reality there always come a point where feasibility or finances are #1.

You know what isn't putting safety as a primary concern? Only focusing on MCAS and ignoring the other significant factors at play in these crashes. Like the CEO said, the accidents were a chain of events. Boeing will fix their link (and it's the easiest to fix). It's up to the rest of the world to improve the other links.
 
kalvado
Posts: 2896
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 5:08 pm

morrisond wrote:
kalvado wrote:
OldAeroGuy wrote:

Neither airplane needed to be at 250 KIAS with the Flaps extended. For ET302, stick shaker started at 150 kts. and the Flaps 5 placard is 250 KIAS. Both crews had control over speed by either changing their climb angle or reducing thrust.

A good starting point would have been to do the Flaps down "Airspeed Unreliable" QRH procedure: 80% N1 and 10 deg pitch attitude. There was never a need to retract the Flaps.

I tried to bring it up before.. These are ballpark conditions for maintaining altitude. There is something specific in ET situation: hot and high airport with nearby mountains. Would those recommended conditions allow a safe climb above terrain? Yes, engine out performance should be such that they can get above mountains with reduced thrust - but would a handicap of extended gear and flaps outweigh that performance of extra engine?


Yes apparently they are sufficient for all situations - at lower altitudes (assume under 20,000') it will produce a climb.

One thing not talked about much on this website but came from the Flight Global article is that they never deviated from Take Off thrust. Apparently that is different from Climb thrust and they did not even adjust down to this value.

94% would have have been the computed take-off thrust - what would climb thrust been?

Brought up many times. For me it is perfectly obvious: one pilot is fighting with yoke, the other is with trim wheel. Thrust is way lower in priority. Assuming trim would be actually movable, 30 seconds to return trim to a managable state, there would be no issue with overspeed or engine.
As for "it results in climb" - is the rate of climb sufficient to avoid mountains? In a plane which may or may not handle a turn?
 
flyer737sw
Posts: 146
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 5:10 pm

All Safety features should be “standard” equipment from this point going forward. Period
 
kalvado
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Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 5:16 pm

MSPNWA wrote:
art wrote:
I heard a little of what the Boeing representative said. He maintained that the primary consideration was always safety. If that were true the company would have redesigned the wingbox (or whatever) to avoid pushing the engines forward and up on the successor to NG, Or gone for NSA.

Which was not done because Boeing's secondary consideration was safety. Their primary consideration was maintaining market share by producing an A320NEO competitor ASAP..


Insider hint (not): Safety is always in a balance with other factors. One can say it's #1, but in reality there always come a point where feasibility or finances are #1.

You know what isn't putting safety as a primary concern? Only focusing on MCAS and ignoring the other significant factors at play in these crashes. Like the CEO said, the accidents were a chain of events. Boeing will fix their link (and it's the easiest to fix). It's up to the rest of the world to improve the other links.

Well, lets say very conservatively - Boeing should shoulder 99.5% of fault over here, maybe a touch more. We may talk about remaining fraction of a problem - which surely will include crew actions.
 
OldAeroGuy
Posts: 3926
Joined: Sun Dec 05, 2004 6:50 am

Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 5:18 pm

kalvado wrote:
I tried to bring it up before.. These are ballpark conditions for maintaining altitude. There is something specific in ET situation: hot and high airport with nearby mountains. Would those recommended conditions allow a safe climb above terrain? Yes, engine out performance should be such that they can get above mountains with reduced thrust - but would a handicap of extended gear and flaps outweigh that performance of extra engine?


Gear would not have been extended and Flaps 5 L/D is perhaps 40% lower than Flaps Up. The loss in L/D is more than made up by having 100% more engine thrust (two engines vs one engine). Plenty of climb performance would have been available.

In addition, ET302 crew were at their home airport in clear air. Maneuvering for an immediate return to land should have been a non-event.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
morrisond
Posts: 2772
Joined: Thu Jan 07, 2010 12:22 am

Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 5:18 pm

Interested wrote:
Interested wrote:
BravoOne wrote:


I see nothing in the Boeing documents that supports this line of thinking. I'll keep looking but I would not get two wrapped up in this issue.


The Wall Street Journal article said that Boeing have still not answered why they turned off the the AOA disagree feature without informing customers.

The Journal has also had sight of internal emails about this issues between FAA officials - one of whom wrote:

"It would be irresponsible to have MAX aircraft operating with AOA Disagree Warning system inoperative"

And they discussed grounding the planes until it was fixed

The concerns were then dismissed higher up the chain.

In today's press conference the CEO said these warnings would now be standard at Boeing's expense and will be retro-fitted on every MAX plane


In the press conference the CEO said even without the warning lights the pilots had all the information they needed to fly the plane. And that pilots need things like altitude and speed info to fly planes and they were all part of what was on screens to allow them to fly the MAX safely. And that the warning lights aren't necessary etc etc etc

He had an answer for every mistake

He's even better than Morisson!!


It's obvious I coached him.
 
kalvado
Posts: 2896
Joined: Wed Mar 01, 2006 4:29 am

Re: B737MAX Grounded Worldwide

Mon Apr 29, 2019 5:22 pm

flyer737sw wrote:
All Safety features should be “standard” equipment from this point going forward. Period

AoA disagree wasn't really considered a safety feature. And it is really formal thing: can Boeing add certain safety things as product matures? If yes - should it be still safe to fly older frames without those new features? Should it be possible to buy planes in the old config, in the name of fleet commonality, for example?

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