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mjoelnir
Posts: 9391
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 11:03 am

osiris30 wrote:
Planetalk wrote:
osiris30 wrote:

https://www.reuters.com/article/us-ethi ... SKCN1R20WD

The pilot may have been briefed but wasn't 'trained' as far as I can tell. There were a few clearer articles that I can't find immediately, but the search terms are a bit tricky. I will try to find the others later.


This was extensively discussed earlier. Despite the article's attempt to sensationalise the issue, it actually shows Ethiopian Airlines to have been ahead of the game as they were amongst the first in the world to be getting hold of the simulators, which practically noone currently has. So yes the CEO was absolutely correct saying they had received the new training.

So hopefully we will all acknowledge and give credit where it is true for Ethiopian apparently being leaders on this , rather than bringing up already debunked media nonsense to throw more dirt at the pilots and the airline.


I am not throwing any dirt in anyone. I am saying there are conflicting reports. Then provided evidence of conflicting reports. Your turn: provide evidence ET are leaders in this area.


Very simply, Ethiopian got a 737MAX simulator. Non of the USA airlines having grounded the MAX, got one. It is not Ethiopians fault, that Boeing has hidden MCAS so well, that non of the MAX simulators sold to customers are able to provide MCAS training or the effects of AOA sensor failure (or its downstream electronics).
So Ethiopian was at least leading the USA airlines.
 
Pluto707
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 11:13 am

The crucifixion has started, Boeing will suffer !! https://www.abc.net.au/news/2019-03-29/ ... h/10951772
 
XRAYretired
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 11:23 am

There are a number of news outlets quoting un-named sources briefed on the investigation saying MCAS was active during the death dive and AOA sensor was thought to be providing incorrect data. Also reported the crash site is being searched specifically for the AOA sensors that have not yet been found.

Veracity?

Ray
 
morrisond
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 11:25 am

SomebodyInTLS wrote:
osiris30 wrote:
Stall recovery is routinely practiced in sims and is part of the check ride (sim) for ?many/most/all? airlines.


Nope...

Recovery from APPROACH to stall is practiced regularly. Because that's what simulators can actually simulate and what systems are actually designed around and what training is actually based on.

You are never supposed to actually get to be in a stall since then all bets are off.


Stop with the melodramatics. No Certified aircraft would ever be certified unless it was easily recoverable from a stall - it's why the COG is in front of the COL (Center of Lift) in order to help bring the nose down if the pilot is so inept and allowed a stall to fully develop. As the MAX's COG is more forward than the NG it should actually be easier to get out of a stall.

It would not be very uncomfortable in the back - but it is a basic flight maneouver to practise recovery from stall time and time again in training. By the time a pilot gets to a commercial flight deck they should have done this at least 100 times (at least I did in Canada plus spin recovery which is pretty basic to get out of as well although that is not taught many places in the world) and it should be considered something to fear.

Actually it was quite boring - there is tons of time to recover.

Watch this video - it is on one of the first simulators certified for full stall training on the 737. You literally have to force the aircraft into the stall and the recovery is quite benign - it looks just like it does in a Cessna or almost any other airplane.

https://www.youtube.com/watch?v=zCJco59tqoQ
 
Etheereal
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 11:35 am

mxaxai wrote:
jollo wrote:
To put things in perspective: in the whole service history of the A3XX family there is exactly one recorded occurrence of a double sensor failure preventing a triple-redundant envelope protection system to work as expected (and that plane only crashed because pilots were improvising test protocols at low altitude). Frequency = 1 / number of flights since 1988.

eh ...
http://avherald.com/h?article=40de5374/0006&opt=0
Automatic nose down command after a single faulty AoA sensor confused the ADIRU.

http://avherald.com/h?article=47d74074/0000&opt=0
Alpha prot / Automatic nose down command due to 2 frozen AoA vanes (of 3).

And that's without frozen or damaged pitot tubes, which can also trigger stall warnings and all the nice things that come along.

On the other hand, this 787 handled iced pitot tubes quite well, but they had a skilled crew too.
http://avherald.com/h?article=49126557&opt=0

Excuse me, but AF447 lost ALL protections because all the pitot tubes froze. So you forgot that as well. (this message is directed to jollo btw).
 
dragon6172
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 11:40 am

asdf wrote:

look at the FDR diagram of the lion air crash
electric up trim movement commanded by the console only in those timeframes when there is no trim down command from MCAS

will you suggest that it is simple coincidence that the crew only tried to trim the nose up when MCAS was not trimming down?
they only could apply 5 seconds then MCAS comes into play

the FDR data sheet with the 0/1 imputs is some douzend pages behind here in the thread

It's not coincidence... it is the pilots over riding MCAS. Every time the pilot makes an input with the trim switch MCAS inputs stop. Pretty clear on the FDR traces.

Look closely at the FDR traces and you can see that the ONLY time MCAS made a full 10 second / 2.5 degree trim change was the very first incident after takeoff. Every other MCAS input was less than 10 seconds, most probably around 5-6 seconds, because the pilot made a trim input that over rode MCAS.
Phrogs Phorever
 
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PixelFlight
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 11:52 am

Etheereal wrote:
Excuse me, but AF447 lost ALL protections because all the pitot tubes froze. So you forgot that as well. (this message is directed to jollo btw).

No. AF447 go to Alternate law 2 (ALT2): loses normal law lateral mode (replaced by roll direct mode and yaw alternate mode) along with pitch attitude protection, bank angle protection and low energy protection. Load factor protection is retained. High angle of attack and high speed protections are retained unless the reason for alternate law 2 mode is the failure of two air-data references or if the two remaining air data references disagree.
:stirthepot: 737-8 MAX: "For all speeds higher than 220 Kts and trim set at a value of 2.5 units, the difficulity level of turning the manual trim wheel was level A (trim wheel not movable)." :stirthepot:
 
mjoelnir
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 11:59 am

Etheereal wrote:
mxaxai wrote:
jollo wrote:
To put things in perspective: in the whole service history of the A3XX family there is exactly one recorded occurrence of a double sensor failure preventing a triple-redundant envelope protection system to work as expected (and that plane only crashed because pilots were improvising test protocols at low altitude). Frequency = 1 / number of flights since 1988.

eh ...
http://avherald.com/h?article=40de5374/0006&opt=0
Automatic nose down command after a single faulty AoA sensor confused the ADIRU.

http://avherald.com/h?article=47d74074/0000&opt=0
Alpha prot / Automatic nose down command due to 2 frozen AoA vanes (of 3).

And that's without frozen or damaged pitot tubes, which can also trigger stall warnings and all the nice things that come along.

On the other hand, this 787 handled iced pitot tubes quite well, but they had a skilled crew too.
http://avherald.com/h?article=49126557&opt=0

Excuse me, but AF447 lost ALL protections because all the pitot tubes froze. So you forgot that as well. (this message is directed to jollo btw).


With AF447 the pilots forced the airplane into a stall. The frozen pilot tubes did not gave wrong or unreliable stall warning. The frozen pilot tubes produced unreliable or not indicated airspeed and there are procedures to overcome that.
 
Etheereal
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 12:06 pm

PixelFlight wrote:
Etheereal wrote:
Excuse me, but AF447 lost ALL protections because all the pitot tubes froze. So you forgot that as well. (this message is directed to jollo btw).

No. AF447 go to Alternate law 2 (ALT2): loses normal law lateral mode (replaced by roll direct mode and yaw alternate mode) along with pitch attitude protection, bank angle protection and low energy protection. Load factor protection is retained. High angle of attack and high speed protections are retained unless the reason for alternate law 2 mode is the failure of two air-data references or if the two remaining air data references disagree.


Yes, and AF447 happened precisely because the reason the controls went into ALT2 was due all ADIRS disagreed due freezing.

Yes Mjoenir, there's recovery proceedures for stalling in an Airbus, but i wasnt questioning whether you can or not stall an Airbus, but showing that there have been more examples of pitot/aoa problems with the A3XX family. Also, i know the data wasnt wrong, it was simply that they got stuck due freezing, which made them unreliable.
 
mjoelnir
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 12:20 pm

Etheereal wrote:
PixelFlight wrote:
Etheereal wrote:
Excuse me, but AF447 lost ALL protections because all the pitot tubes froze. So you forgot that as well. (this message is directed to jollo btw).

No. AF447 go to Alternate law 2 (ALT2): loses normal law lateral mode (replaced by roll direct mode and yaw alternate mode) along with pitch attitude protection, bank angle protection and low energy protection. Load factor protection is retained. High angle of attack and high speed protections are retained unless the reason for alternate law 2 mode is the failure of two air-data references or if the two remaining air data references disagree.


Yes, and AF447 happened precisely because the reason the controls went into ALT2 was due all ADIRS disagreed due freezing.

Yes Mjoenir, there's recovery proceedures for stalling in an Airbus, but i wasnt questioning whether you can or not stall an Airbus, but showing that there have been more examples of pitot/aoa problems with the A3XX family.


The problem with AF447 was not stalling, but unreliable airspeed. The reaction of the pilots was pulling maximum elevator on the side stick, putting the aircraft in a stall and holding the aircraft in the stall until it crashed into the sea.

You compare that with the 737MAX trying to kill its pilots and passengers, with an undocumented feature going on at the wrong time, prompted likely by an defect sensor. Furthermore that happened twice in a short time period producing two losses of frames with all hands.

And you start out with AF447 lost protection. That is incorrect. All that AF447 lost was air speed indication and therefor dropped out of autopilot. And just to remind you, unreliable airspeed was one of the problems both the Lion Air and Ethiopian had to fight with.
 
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SheikhDjibouti
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 12:26 pm

morrisond wrote:
... it is a basic flight maneouver to practise recovery from stall time and time again in training. By the time a pilot gets to a commercial flight deck they should have done this at least 100 times (at least I did in Canada plus spin recovery which is pretty basic to get out of as well although that is not taught many places in the world) and it should be considered something to fear.

Actually it was quite boring - there is tons of time to recover.

Please, PLEASE tell me you are a regular big jet pilot. It doesn't have to be a MAX or even a 737, just any transport category aircraft with jet engines and a swept wing.

I have been asking for such an answer for days now, and all I hear is
1) Large jets are stalled all the time / fairly frequently. Or failing that "most airline pilots have done it at some point".
Funny, but I don't hear anything about it. Maybe it's so routine and "boring" nobody even mentions it. :roll:
I know some of the real airline pilots on these forums, and so far not one of them has come forward.

2) They practice stall training on simulators
Er, no. This is blatant wishful thinking ("lying" is such an ugly word).
My point for days now has been that they practice the approach to a stall, and how to avoid entering the stall.
The fact that in 2013 the FAA invited sim manufacturers to introduce full stall capability to their sims tells us it didn't exist before.
And now you pull a youtube video out of a hat which confirms this procedure is only now being introduced in 2019 by Alaska. Doh!

3) Stall are easy; I've done them 100's of times. (sotto voce ...in a Cessna)
By the time a pilot gets to a commercial flight deck they should have done this at least 100 times

This is indeed news to me.
It also goes against every other commentator on the internet, many of whom volunteer their real name and actual qualifications to speak on this matter.
I realise on a.net you are allowed to protect your identity, and I don't have a problem with that. But I haven't seen you even hint at your actual qualifications, so please excuse me if I prefer to believe those that do.

I want to hear from a 737 or A320 pilot, not a test pilot, not a CFI, not a senior check pilot, not an ex-military fast jet ace. Just an ordinary 737 or A320 pilot.

Have you ever stalled a 737 or A320 with or without passengers, and is it considered routine procedure?

So, morrisond & osiris30 - have you? You have both fought tooth & nail on this issue as if you have some special insight into this matter. :scratchchin:
Nothing to see here; move along please.
 
Etheereal
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 12:28 pm

Let me make something clear, since it seems im not being understood properly. I'm not comparing the 330 series with the Max. Someone on the last 5 pages said something that there was ONLY one documented case of the A3XX series where the "sensors" all became unreliable, which im trying to say its false as there are at least 2 more examples, including AF447.

They lost AoA protection because if the ADIRS hadnt frozen and mismatched each other, then they wouldnt have been able to get that 35-45° pitch up angle they ended upon.
 
namezero111111
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 12:37 pm

SheikhDjibouti wrote:
Have you ever stalled a 737 or A320 with or without passengers, and is it considered routine procedure?


I doubt stalling a 737/A320 with passengers on board would ever be considered "routine" procedure.
 
mjoelnir
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 12:46 pm

Etheereal wrote:
Let me make something clear, since it seems im not being understood properly. I'm not comparing the 330 series with the Max. Someone on the last 5 pages said something that there was ONLY one documented case of the A3XX series where the "sensors" all became unreliable, which im trying to say its false as there are at least 2 more examples, including AF447.

They lost AoA protection because if the ADIRS hadnt frozen and mismatched each other, then they wouldnt have been able to get that 35-45° pitch up angle they ended upon.


Point taken. But the talk was about AoA sensors.
 
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SheikhDjibouti
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 12:49 pm

AirFiero wrote:
morrisond wrote:
Seriously - specific training? This is part of basic training on any aircraft and I'm sure Pilots do this in the simulator all the time.

Drop the nose or apply power and pick up the wing that drops with the rudder (if it drops).

If a pilot can't do this they would never be allowed to Solo a Cessna.

If you believe Commercial Pilots should be allowed to fly without knowing this basic knowledge then I hope they do remove Pilots from the cockpit really soon as we would be better off with Computers and just accept the fact that Computers will screw up every once in a while and accept the crashes.

You are correct about stalls in Cessna. Something I recently learned from a commercial pilots YouTube video (Mentour Pilot, one of a regular series he does), is that in a 737 you do not want to apply full power immediately. Evidently, the engines are so powerful it will actually make the initial part of the stall recovery worse by pitching the nose up.

morrisond wrote:
Interesting - I didn't know that ...

Funnily enough, I did already know that. And I haven't stalled an aircraft 100s of time like yourself.

This pitching up when applying power is partly due to the sheer power of the engines, and partly due to their positioning. Particularly in the MAX.

In fact, aren't we now coming full circle, back to part of the reason for MCAS in the first place - to mitigate against the natural tendency of a 737 MAX to pitch up when applying power as a natural reaction to avoid the early onset of a stall.

It's a Catch-22.

On the approach to a stall, the normal correct procedure is to add more power in order to prevent the stall.

However, if that fails, once the stall is inevitable, for the MAX the best policy is to reduce power in order to get the nose down, and only then pile it on to pick up airspeed.

If only we had somebody here with real experience of 100s of such stalling events...…. :scratchchin:
Nothing to see here; move along please.
 
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smittythepirate
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 12:56 pm

Pluto707 wrote:
The crucifixion has started, Boeing will suffer !! https://www.abc.net.au/news/2019-03-29/ ... h/10951772


You seen really excited about this for some reason...
www.jbweather.com
 
Etheereal
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 1:02 pm

mjoelnir wrote:
Etheereal wrote:
Let me make something clear, since it seems im not being understood properly. I'm not comparing the 330 series with the Max. Someone on the last 5 pages said something that there was ONLY one documented case of the A3XX series where the "sensors" all became unreliable, which im trying to say its false as there are at least 2 more examples, including AF447.

They lost AoA protection because if the ADIRS hadnt frozen and mismatched each other, then they wouldnt have been able to get that 35-45° pitch up angle they ended upon.


Point taken. But the talk was about AoA sensors.

ADIRS on airbuses also include the AoA sensor (An air data inertial reference unit (ADIRU) is a key component of the integrated air data inertial reference system (ADIRS), which supplies air data (airspeed, angle of attack and altitude) and inertial reference (position and attitude) information to the pilots' electronic flight instrument system displays as well as other systems on the aircraft such as the engines, autopilot, aircraft flight control system and landing gear systems.[1] An ADIRU acts as a single, fault tolerant source of navigational data for both pilots of an aircraft.[2] It may be complemented by a secondary attitude air data reference unit (SAARU), as in the Boeing 777 design.[3] )
 
dragon6172
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 1:25 pm

SheikhDjibouti wrote:
This pitching up when applying power is partly due to the sheer power of the engines, and partly due to their positioning. Particularly in the MAX.

In fact, aren't we now coming full circle, back to part of the reason for MCAS in the first place - to mitigate against the natural tendency of a 737 MAX to pitch up when applying power as a natural reaction to avoid the early onset of a stall.



MAX engines only have a slight increase in power over NG (about 700 lb thrust more) and are not slung lower than those on the NG. The pitch up tendency that MCAS is installed to prevent comes from the fact that the LARGER NACELLES create lift when the aircraft angle of attack is above a certain amount. Because the nacelles are forward of the CG this lift causes a pitch up moment.

This has been covered at least 100 times between the three main MAX threads.
Phrogs Phorever
 
barney captain
Posts: 2332
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 2:50 pm

SheikhDjibouti wrote:
morrisond wrote:
... it is a basic flight maneouver to practise recovery from stall time and time again in training. By the time a pilot gets to a commercial flight deck they should have done this at least 100 times (at least I did in Canada plus spin recovery which is pretty basic to get out of as well although that is not taught many places in the world) and it should be considered something to fear.

Actually it was quite boring - there is tons of time to recover.

Please, PLEASE tell me you are a regular big jet pilot. It doesn't have to be a MAX or even a 737, just any transport category aircraft with jet engines and a swept wing.

I have been asking for such an answer for days now, and all I hear is
1) Large jets are stalled all the time / fairly frequently. Or failing that "most airline pilots have done it at some point".
Funny, but I don't hear anything about it. Maybe it's so routine and "boring" nobody even mentions it. :roll:
I know some of the real airline pilots on these forums, and so far not one of them has come forward.

2) They practice stall training on simulators
Er, no. This is blatant wishful thinking ("lying" is such an ugly word).
My point for days now has been that they practice the approach to a stall, and how to avoid entering the stall.
The fact that in 2013 the FAA invited sim manufacturers to introduce full stall capability to their sims tells us it didn't exist before.
And now you pull a youtube video out of a hat which confirms this procedure is only now being introduced in 2019 by Alaska. Doh!

3) Stall are easy; I've done them 100's of times. (sotto voce ...in a Cessna)
By the time a pilot gets to a commercial flight deck they should have done this at least 100 times

This is indeed news to me.
It also goes against every other commentator on the internet, many of whom volunteer their real name and actual qualifications to speak on this matter.
I realise on a.net you are allowed to protect your identity, and I don't have a problem with that. But I haven't seen you even hint at your actual qualifications, so please excuse me if I prefer to believe those that do.

I want to hear from a 737 or A320 pilot, not a test pilot, not a CFI, not a senior check pilot, not an ex-military fast jet ace. Just an ordinary 737 or A320 pilot.

Have you ever stalled a 737 or A320 with or without passengers, and is it considered routine procedure?

So, morrisond & osiris30 - have you? You have both fought tooth & nail on this issue as if you have some special insight into this matter. :scratchchin:


Maybe I can help -

You would never practice any stall maneuver in a 737 (testing certification notwithstanding).

You DO practice stalls while working on your ratings in smaller GA aircraft - quite regularly.

Up until last year in the US, we routinely practiced approach to stall maneuvers in the sim.

Starting last year, the FAA mandated advanced maneuvering training that requires us to fully stall the aircraft at both low and high altitudes and practice recovery. Again, in the sim only.
Southeast Of Disorder
 
PlanesNTrains
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 3:08 pm

marcelh wrote:
PlanesNTrains wrote:
GalebG4 wrote:
Boeing you made a huge mistake. Accept it and get on with it, I don’t care about your airliners.net forum protectionists who will protect you no matter what. You made mistake, pay the families of the victims. Anybody could be in that plane(even you Boeing airliners.net forum protectionist- keyboard employee warrior) with uniformed pilots about system. This is your fault Boeing so stop being sneaky and trying to say we haven’t done anything wrong. You have, people died second time for the same reason.

Please don’t answer any Boeing airlines.net forum protectionists-keyboard warriors, because that’s spiting on people that have innocently died.


You’re great at casting stones. How about we wait for the investigation?

Pot...kettle...black :ziplip:


Can I get an example so I understand what you’re talking about?
-Dave


MAX’d out on MAX threads. If you are starting a thread, and it’s about the MAX - stop. There’s already a thread that covers it.
 
morrisond
Posts: 2648
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 3:26 pm

SheikhDjibouti wrote:
AirFiero wrote:
morrisond wrote:
Seriously - specific training? This is part of basic training on any aircraft and I'm sure Pilots do this in the simulator all the time.

Drop the nose or apply power and pick up the wing that drops with the rudder (if it drops).

If a pilot can't do this they would never be allowed to Solo a Cessna.

If you believe Commercial Pilots should be allowed to fly without knowing this basic knowledge then I hope they do remove Pilots from the cockpit really soon as we would be better off with Computers and just accept the fact that Computers will screw up every once in a while and accept the crashes.

You are correct about stalls in Cessna. Something I recently learned from a commercial pilots YouTube video (Mentour Pilot, one of a regular series he does), is that in a 737 you do not want to apply full power immediately. Evidently, the engines are so powerful it will actually make the initial part of the stall recovery worse by pitching the nose up.

morrisond wrote:
Interesting - I didn't know that ...

Funnily enough, I did already know that. And I haven't stalled an aircraft 100s of time like yourself.

This pitching up when applying power is partly due to the sheer power of the engines, and partly due to their positioning. Particularly in the MAX.

In fact, aren't we now coming full circle, back to part of the reason for MCAS in the first place - to mitigate against the natural tendency of a 737 MAX to pitch up when applying power as a natural reaction to avoid the early onset of a stall.

It's a Catch-22.

On the approach to a stall, the normal correct procedure is to add more power in order to prevent the stall.

However, if that fails, once the stall is inevitable, for the MAX the best policy is to reduce power in order to get the nose down, and only then pile it on to pick up airspeed.

If only we had somebody here with real experience of 100s of such stalling events...…. :scratchchin:



Yes if you were 737 Qualified you would know that's how a 737 reacted in a stall and you do not apply power first.

The first natural reaction in any stall is to lower the nose first- not apply power.

Do you think 737 Pilots are not taught how to get out of a stall?

As for my qualifications - I do hold a Private Pilots License in Canada with about 120 hours (probably but I haven't flown in about 10 years so I understand flight dynamics.

Did you watch the video I posted above? That simulator is certified for full stall training on an 737 - it looks just like the sight picture of a Cessna in stall.

Here it is again https://www.youtube.com/watch?v=zCJco59tqoQ

Does the airplane look wildly out of control?

What are your qualifications?
 
marcelh
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 3:36 pm

PlanesNTrains wrote:
marcelh wrote:
PlanesNTrains wrote:

You’re great at casting stones. How about we wait for the investigation?

Pot...kettle...black :ziplip:


Can I get an example so I understand what you’re talking about?


Also some Boeing “enthousiasts” are casting stones by - for example - blaming the “third world” pilots by crashing the plane. Nothing personal, just an observation.
 
Backseater
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 4:32 pm

Just out of curiosity, here is a picture of a mechanic checking the AoA sensor alignment on a Lion Air 737 MAX (from Chinese TV network)
Image

I believe he is using a J34002-19 tool licensed from Boeing. I think it works as follows. The tool is temporarily attached to the sensor by two thumb screws, thus getting a horizontal reference (of course provided the a/c is parked on flat ground!). An angle is then selected by rotating the tool upper surface and the swept vane.
Image

Besides that alignment procedure, the question remains regarding the "calibration" of the Rosemount 0861FL1 sensor itself. Such calibration had to be performed at the factory (cert. TSO-C54) to compensate for the physical properties of each device.
 
mandala499
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 5:01 pm

SheikhDjibouti wrote:
I want to hear from a 737 or A320 pilot, not a test pilot, not a CFI, not a senior check pilot, not an ex-military fast jet ace. Just an ordinary 737 or A320 pilot.

I have talked to witnesses (pilots, instructors, and other trained personnel) of a particular pilot here who used to do stall testing on post maintenance flights. Contrary to company procedures, this guy would not only test stick shaker, he'd go and actually stall the damn 737-300... He does it on a regular basis, only to go and show his balls to those onboard. Let's just say, those onboard didn't like what he was doing (they would use the term losing one of their balls when the guy pulled his stunts...
The guy was happened to be a DGCA designated instructor and check pilot...
The airline threw him out, he moved to another carrier as an inspector... that second carrier then revoke his DGCA previledges on company aircraft, and sent him back to the DGCA... and he ended up flying at a 3rd carrier without his instructor/checker/inspector previleges... (how he can keep his license without losing his life)... The insurers don't like him.

I agree... only test pilots test swept wing jetliner aircraft in a stall. Regular pilots don't.... for a good reason... the main one, the insurers don't like regular pilots stalling swept wing commercial jets.

Pilots are taught how to get out of a stall, but they are not expected to stall their swept wing jets.

morrisond wrote:
Does the airplane look wildly out of control?

Oh yeah, not out of control... LOL... of course...

Here's one for you to see... https://www.youtube.com/watch?v=L2CsO-Vu7oc
And this one is also fun... https://www.youtube.com/watch?v=FzUakyCFYSc

Enjoy...
When losing situational awareness, pray Cumulus Granitus isn't nearby !
 
dakota123
Posts: 241
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 5:14 pm

SheikhDjibouti wrote:
AirFiero wrote:
morrisond wrote:
Seriously - specific training? This is part of basic training on any aircraft and I'm sure Pilots do this in the simulator all the time.

Drop the nose or apply power and pick up the wing that drops with the rudder (if it drops).

If a pilot can't do this they would never be allowed to Solo a Cessna.

If you believe Commercial Pilots should be allowed to fly without knowing this basic knowledge then I hope they do remove Pilots from the cockpit really soon as we would be better off with Computers and just accept the fact that Computers will screw up every once in a while and accept the crashes.

You are correct about stalls in Cessna. Something I recently learned from a commercial pilots YouTube video (Mentour Pilot, one of a regular series he does), is that in a 737 you do not want to apply full power immediately. Evidently, the engines are so powerful it will actually make the initial part of the stall recovery worse by pitching the nose up.

morrisond wrote:
Interesting - I didn't know that ...

Funnily enough, I did already know that. And I haven't stalled an aircraft 100s of time like yourself.

This pitching up when applying power is partly due to the sheer power of the engines, and partly due to their positioning. Particularly in the MAX.

In fact, aren't we now coming full circle, back to part of the reason for MCAS in the first place - to mitigate against the natural tendency of a 737 MAX to pitch up when applying power as a natural reaction to avoid the early onset of a stall.

It's a Catch-22.

On the approach to a stall, the normal correct procedure is to add more power in order to prevent the stall.

However, if that fails, once the stall is inevitable, for the MAX the best policy is to reduce power in order to get the nose down, and only then pile it on to pick up airspeed.

If only we had somebody here with real experience of 100s of such stalling events...…. :scratchchin:


Any plane with the thrust line below the center of mass will pitch up on an increase in power. Indeed, the MAX’s thrust line is higher than the NG’s. All else being equal (which it isn’t, of course), the MAX would have less pitch up on power application.
“And If I claim to be a wise man, well surely it means that I don’t know”
 
PC12Fan
Posts: 2130
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 5:15 pm

marcelh wrote:
PlanesNTrains wrote:
marcelh wrote:
Pot...kettle...black :ziplip:


Can I get an example so I understand what you’re talking about?


Also some Boeing “enthousiasts” are casting stones by - for example - blaming the “third world” pilots by crashing the plane. Nothing personal, just an observation.


And the same thing would be happening if the shoe was on the other foot.

Sad, but true. :ashamed:
Just when I think you've said the stupidest thing ever, you keep talkin'!
 
PlanesNTrains
Posts: 9524
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 5:19 pm

marcelh wrote:
PlanesNTrains wrote:
marcelh wrote:
Pot...kettle...black :ziplip:


Can I get an example so I understand what you’re talking about?


Also some Boeing “enthousiasts” are casting stones by - for example - blaming the “third world” pilots by crashing the plane. Nothing personal, just an observation.


Then why not join me in calling this sort of one-sided nonsense out? I’ve got plenty of B fanboys who I either have pushed back on or put on my foe list because I can’t stand the rhetoric. The only reason I commented on the other fellow’s post was because he pretty much was labeling anyone with a different point of view as Boeing apologists. Hence - at that point - best to wait for the investigation.
-Dave


MAX’d out on MAX threads. If you are starting a thread, and it’s about the MAX - stop. There’s already a thread that covers it.
 
morrisond
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 5:22 pm

mandala499 wrote:
SheikhDjibouti wrote:
I want to hear from a 737 or A320 pilot, not a test pilot, not a CFI, not a senior check pilot, not an ex-military fast jet ace. Just an ordinary 737 or A320 pilot.

I have talked to witnesses (pilots, instructors, and other trained personnel) of a particular pilot here who used to do stall testing on post maintenance flights. Contrary to company procedures, this guy would not only test stick shaker, he'd go and actually stall the damn 737-300... He does it on a regular basis, only to go and show his balls to those onboard. Let's just say, those onboard didn't like what he was doing (they would use the term losing one of their balls when the guy pulled his stunts...
The guy was happened to be a DGCA designated instructor and check pilot...
The airline threw him out, he moved to another carrier as an inspector... that second carrier then revoke his DGCA previledges on company aircraft, and sent him back to the DGCA... and he ended up flying at a 3rd carrier without his instructor/checker/inspector previleges... (how he can keep his license without losing his life)... The insurers don't like him.

I agree... only test pilots test swept wing jetliner aircraft in a stall. Regular pilots don't.... for a good reason... the main one, the insurers don't like regular pilots stalling swept wing commercial jets.

Pilots are taught how to get out of a stall, but they are not expected to stall their swept wing jets.

morrisond wrote:
Does the airplane look wildly out of control?

Oh yeah, not out of control... LOL... of course...

Here's one for you to see... https://www.youtube.com/watch?v=L2CsO-Vu7oc
And this one is also fun... https://www.youtube.com/watch?v=FzUakyCFYSc

Enjoy...


No pilots are not expected to stall their fixed wing jets - it is exceedingly difficult to do - but the recovery is not that difficult - Max and A320 don't have the same sweep as earlier jets (707,747).

I take it the pilot in the above example is still alive? It must not have been that hard to get out of the stall.

The first one was a stall coaxed into a spin. That does require some effort.

The other they are stalling it multiple times - not that it is not falling out of the shy and "All Bets are off"
 
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SheikhDjibouti
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 6:22 pm

SheikhDjibouti wrote:
Please, PLEASE tell me you are a regular big jet pilot. It doesn't have to be a MAX or even a 737, just any transport category aircraft with jet engines and a swept wing.

I have been asking for such an answer for days now, and all I hear is
1) Large jets are stalled all the time / fairly frequently. Or failing that "most airline pilots have done it at some point".

2) They practice stall training on simulators
My point for days now has been that they practice the approach to a stall, and how to avoid entering the stall.
The fact that in 2013 the FAA invited sim manufacturers to introduce full stall capability to their sims tells us it didn't exist before.

3) Stall are easy; I've done them 100's of times. (sotto voce ...in a Cessna)
By the time a pilot gets to a commercial flight deck they should have done this at least 100 times


I want to hear from a 737 or A320 pilot, not a test pilot, not a CFI, not a senior check pilot, not an ex-military fast jet ace. Just an ordinary 737 or A320 pilot.

Have you ever stalled a 737 or A320 with or without passengers, and is it considered routine procedure?

So, morrisond & osiris30 - have you? You have both fought tooth & nail on this issue as if you have some special insight into this matter. :scratchchin:


barney captain wrote:
Maybe I can help -

You would never practice any stall maneuver in a 737 (testing certification notwithstanding).

You DO practice stalls while working on your ratings in smaller GA aircraft - quite regularly.

Up until last year in the US, we routinely practiced approach to stall maneuvers in the sim.

Starting last year, the FAA mandated advanced maneuvering training that requires us to fully stall the aircraft at both low and high altitudes and practice recovery. Again, in the sim only.

Thank you so much. (assuming that you are qualified to comment....)

(I'm not doubting it one iota, but since I queried those who argued against me, I shouldn't automatically accept you simply because you confirm everything I said :lol: )
Nothing to see here; move along please.
 
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SomebodyInTLS
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 9:48 pm

morrisond wrote:
SomebodyInTLS wrote:
You are never supposed to actually get to be in a stall since then all bets are off.


Stop with the melodramatics.


A factual correction is melodrama?! (BTW, apologies for posting that after several others had already made the same point, been a bit distracted from finishing the thread today.)

No Certified aircraft would ever be certified unless it was easily recoverable from a stall - it's why the COG is in front of the COL (Center of Lift) in order to help bring the nose down if the pilot is so inept and allowed a stall to fully develop. As the MAX's COG is more forward than the NG it should actually be easier to get out of a stall.


See you too are mixing up stall and approach to stall.

And you're ignoring the fact that (every into) stall is governed by aerodynamics, which is exactly the issue with the MAX when at high angles of attack. The CoG may be further forward than in the NG, but that is fixed while the aerodynamic centre moves forward as the AoA increases due to the increasing lift and drag from the nacelles combined with reduced lift from the wing behind them.

It would not be very uncomfortable in the back - but it is a basic flight maneouver to practise recovery from stall time and time again in training.


Wrong. Those pilots are NEVER in a stall during that training.
"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."
 
flybucky
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 9:55 pm

asdf wrote:
you can not trim UP as long as MCAS trimms DOWN
in the time frame MCAS is at work the crew has no authority over the trim

No, the pilots can override MCAS trim at any time with the control column Electric Trim switches, even when MCAS is working. See the Boeing bulletin TBC-19:

"In the event of erroneous AOA data, the pitch trim system can trim the stabilizer nose down in increments lasting up to 10 seconds. The nose down stabilizer trim movement can be stopped and reversed with the use of the electric stabilizer trim switches but may restart 5 seconds after the electric stabilizer trim switches are released."

You may have been confused with by statements like "pilots do not have authority over MCAS", which are probably referring to that pulling full back on the yoke (full elevators) will not be able to compensate for the stabilizer pitch down from MCAS.

asdf wrote:
look at the FDR diagram of the lion air crash
electric up trim movement commanded by the console only in those timeframes when there is no trim down command from MCAS
will you suggest that it is simple coincidence that the crew only tried to trim the nose up when MCAS was not trimming down?
they only could apply 5 seconds then MCAS comes into play

The reason it appears that the crew only trims up when MCAS is not trimming down is because as soon as the crew trims up, MCAS is interrupted. If what you were saying was true, then the MCAS cycles would always be 10 seconds long, since it could not be interrupted while it is working. But you can see from the FDR that the MCAS cycles are not all 10 seconds long because they are being interrupted by the pilot's input.

Image
Last edited by flybucky on Sat Mar 30, 2019 9:59 pm, edited 1 time in total.
 
fadecfault
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 9:57 pm

barney captain wrote:
SheikhDjibouti wrote:
morrisond wrote:
... it is a basic flight maneouver to practise recovery from stall time and time again in training. By the time a pilot gets to a commercial flight deck they should have done this at least 100 times (at least I did in Canada plus spin recovery which is pretty basic to get out of as well although that is not taught many places in the world) and it should be considered something to fear.

Actually it was quite boring - there is tons of time to recover.

Please, PLEASE tell me you are a regular big jet pilot. It doesn't have to be a MAX or even a 737, just any transport category aircraft with jet engines and a swept wing.

I have been asking for such an answer for days now, and all I hear is
1) Large jets are stalled all the time / fairly frequently. Or failing that "most airline pilots have done it at some point".
Funny, but I don't hear anything about it. Maybe it's so routine and "boring" nobody even mentions it. :roll:
I know some of the real airline pilots on these forums, and so far not one of them has come forward.

2) They practice stall training on simulators
Er, no. This is blatant wishful thinking ("lying" is such an ugly word).
My point for days now has been that they practice the approach to a stall, and how to avoid entering the stall.
The fact that in 2013 the FAA invited sim manufacturers to introduce full stall capability to their sims tells us it didn't exist before.
And now you pull a youtube video out of a hat which confirms this procedure is only now being introduced in 2019 by Alaska. Doh!

3) Stall are easy; I've done them 100's of times. (sotto voce ...in a Cessna)
By the time a pilot gets to a commercial flight deck they should have done this at least 100 times

This is indeed news to me.
It also goes against every other commentator on the internet, many of whom volunteer their real name and actual qualifications to speak on this matter.
I realise on a.net you are allowed to protect your identity, and I don't have a problem with that. But I haven't seen you even hint at your actual qualifications, so please excuse me if I prefer to believe those that do.

I want to hear from a 737 or A320 pilot, not a test pilot, not a CFI, not a senior check pilot, not an ex-military fast jet ace. Just an ordinary 737 or A320 pilot.

Have you ever stalled a 737 or A320 with or without passengers, and is it considered routine procedure?

So, morrisond & osiris30 - have you? You have both fought tooth & nail on this issue as if you have some special insight into this matter. :scratchchin:


Maybe I can help -

You would never practice any stall maneuver in a 737 (testing certification notwithstanding).

You DO practice stalls while working on your ratings in smaller GA aircraft - quite regularly.

Up until last year in the US, we routinely practiced approach to stall maneuvers in the sim.

Starting last year, the FAA mandated advanced maneuvering training that requires us to fully stall the aircraft at both low and high altitudes and practice recovery. Again, in the sim only.


What do you think about these incidents? I've spoken to a few of our flights crews (swa) and all of them believe they would have handled the situation correctly.
The views and opinions written here are my own and do not reflect those of my employer.
 
flybucky
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 11:05 pm

Lrockeagle wrote:
speedbored wrote:
Pilots carry out checklists and tasks related to unreliable airspeed
This allows MCAS to kick in
They then have just 40 seconds, during which they are trying to work out why they are getting an unreliable airspeed indication, and which, if any, airspeed indication is correct, while fighting the MCAS trim adjustments to keep the aircraft under control.[/list]

Nobody stood there with a watch and said “you have 40 seconds, go”. Ever think maybe it’s possible they only made it 40 seconds because they forgot to AVIATE?

The "40 seconds" that previous commenter was referring to came from simulator recreations of JT610 flight. If pilots did not counteract MCAS trim down, then had about 40 seconds before the plane was unrecoverable.
https://www.nytimes.com/2019/03/25/busi ... error.html

The point is that if the pilots can't figure out how to aviate/control within 40 seconds, the flight is doomed. This window may have been even shorter for ET302 since they were even lower above ground level.
 
morrisond
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 11:22 pm

SomebodyInTLS wrote:
morrisond wrote:
SomebodyInTLS wrote:
You are never supposed to actually get to be in a stall since then all bets are off.


Stop with the melodramatics.


A factual correction is melodrama?! (BTW, apologies for posting that after several others had already made the same point, been a bit distracted from finishing the thread today.)



By stopping the melodramatics I was referring to the "All bets are off" - A full stall is recoverable from and it does not require superhuman piloting skills- it does not mean automatic crash, in fact the odds of crashing with a qualified pilot would b quite low.

The MAX will stall slightly quicker than the NG - but we are talking slightly - it's way out of the normal flight envelope.
 
flybucky
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 11:46 pm

sgrow787 wrote:
But AOA sensors don't freeze until 32000 ft. Plenty of height to deal with nose down issues.

Do you have a source for that? Why would AOA sensors freezing be dependant on altitude instead of temperature? E.g. why couldn't AOA sensors freeze at 0 ft AMSL when the temperature is cold enough?

In the 2014 Lufthansa A321 incident, "AOA sensor 1 and 2 were frozen while the aircraft was climbing to FL195 with an outside air temperature of -35°C" - https://aviation-safety.net/wikibase/wiki.php?id=171411

Anyways, my original point was that 3 sensors don't completely eliminate risk, they are not 100% fail proof.
 
flybucky
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sat Mar 30, 2019 11:56 pm

speedbored wrote:
AoA sensors? Care to give us a link to the incident report?

2 incidents that I know about with 2 faulty AOA sensors outvoting the 3rd valid one:
2008 A320 acceptance flight - crashed into the sea with no survivors.
2014 A321 Lufthansa 1829 - dropped 4000 ft before the pilots disconnected the ADR and recovered the flight.

speedbored wrote:
But nothing to suggest that the freezing was due to any specific property of the type of sensor being used so no reason to believe that having 3 different sensor types on the aircraft would have made any difference.

Exactly. That's why 3 sensors (while better than 2 sensors) is not fail proof. There needs to be an independent backup AOA calculation that does not rely on AOA sensors.
 
flybucky
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sun Mar 31, 2019 12:04 am

Latest news:
  • FDR shows MCAS was activated.
  • The stick shaker activated on one side.
  • The AOA sensor on that side has not been located yet in the wreckage.
  • FDR showed that the missing AOA sensor was malfunctioning.

Investigators of an Ethiopian Airlines crash have concluded that the same system that malfunctioned in an earlier accident off Indonesia was activated, and they are searching for a key piece of equipment that might explain why.

Preliminary flight data from the Boeing Co. 737 Max jet’s black-box recorder indicates that a new anti-stall system known as MCAS was pushing the plane’s nose down. Searches of the wreckage as of Thursday night had failed to locate the part believed to have been involved.

Evidence from the flight-data recorder of the Ethiopian 737 Max 8 showed that the missing sensor was malfunctioning and that a device known as a “stick-shaker” -- which makes a loud nose and rattles a pilot’s control column to warn of an impending aerodynamic stall -- had been activated on the same side of the aircraft. It could be heard on the cockpit voice recorder, the person said.

The details about the sensor, which haven’t previously been reported, indicate a scenario similar to the one on the final flight of a Lion Air jet that crashed Oct. 29 off the coast of Indonesia.

https://www.bloomberg.com/news/articles ... -for-clues
 
asdf
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sun Mar 31, 2019 12:07 am

morrisond wrote:
Watch this video - it is on one of the first simulators certified for full stall training on the 737. You literally have to force the aircraft into the stall and the recovery is quite benign - it looks just like it does in a Cessna or almost any other airplane.
https://www.youtube.com/watch?v=zCJco59tqoQ


well, seems like it was a simulator like this where they figured out that the lion air crew had a non-recoverable bird in hand after only three (!) MCAS trim inputs.

only 40 seconds to figure out that by some reason they couldnt understand moves the trim from time to time ...

https://www.nytimes.com/2019/03/25/busi ... e=Homepage

John Cox, an aviation safety consultant and a former 737 pilot, said pilots are highly likely to use the thumb switch to extend the 40-second window to several minutes. But that may still not be enough time to diagnose and solve the problem, especially if the pilots, like the Lion Air crew, were not informed of the system.
 
Backseater
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sun Mar 31, 2019 12:18 am

((Edited post))
Just out of curiosity, here is a picture of a mechanic checking the AoA sensor alignment on a Lion Air 737 MAX (from Chinese TV network)
Image

I believe he is using a J34002-19 tool licensed from Boeing. I think it works as follows. The tool is temporarily attached to the sensor by two thumb screws, thus getting a horizontal reference (of course provided the a/c is parked on flat ground!). An angle is then selected by rotating the lower circulate plate and the swept vane.
Image

Besides that alignment procedure, the question remains regarding the "calibration" of the Rosemount 0861FL1 sensor itself. Such calibration had to be performed at the factory (cert. TSO-C54) to establish and compensate for the physical properties of each device. I believe that was done thru software(!) inside the sensor.
 
Aviation737
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sun Mar 31, 2019 12:51 am

SheikhDjibouti wrote:
AirFiero wrote:
morrisond wrote:
Seriously - specific training? This is part of basic training on any aircraft and I'm sure Pilots do this in the simulator all the time.

Drop the nose or apply power and pick up the wing that drops with the rudder (if it drops).

If a pilot can't do this they would never be allowed to Solo a Cessna.

If you believe Commercial Pilots should be allowed to fly without knowing this basic knowledge then I hope they do remove Pilots from the cockpit really soon as we would be better off with Computers and just accept the fact that Computers will screw up every once in a while and accept the crashes.

You are correct about stalls in Cessna. Something I recently learned from a commercial pilots YouTube video (Mentour Pilot, one of a regular series he does), is that in a 737 you do not want to apply full power immediately. Evidently, the engines are so powerful it will actually make the initial part of the stall recovery worse by pitching the nose up.

morrisond wrote:
Interesting - I didn't know that ...

Funnily enough, I did already know that. And I haven't stalled an aircraft 100s of time like yourself.

This pitching up when applying power is partly due to the sheer power of the engines, and partly due to their positioning. Particularly in the MAX.

In fact, aren't we now coming full circle, back to part of the reason for MCAS in the first place - to mitigate against the natural tendency of a 737 MAX to pitch up when applying power as a natural reaction to avoid the early onset of a stall.


I don't think you still understand the reason for the MCAS system at all. MOST airliners have a natural tendency to pitch up when power is applied to the engines, it is not unique only to the MAX. The difference in the MAX is just that it pitches more aggressively than the NG and hence the MCAS is required to help the pilots push the nose down. But it is not impossible for the pilots to push the nose down without the MCAS system on the MAX just more difficult.

SheikhDjibouti wrote:
On the approach to a stall, the normal correct procedure is to add more power in order to prevent the stall.

However, if that fails, once the stall is inevitable, for the MAX the best policy is to reduce power in order to get the nose down, and only then pile it on to pick up airspeed.

If only we had somebody here with real experience of 100s of such stalling events...…. :scratchchin:

Nope, the normal procedural on most airliners including the NG and the MAX is just to push the nose down when the aircraft approaches stall and let gravity help you accelerate. You only increase the throttle once the aircraft passed a certain speed which is dependent on the aircraft type. The reason you do not increase the thrust immediately, like what I said above, is that it will cause the aircraft to pitch even more and risk causing the stall to happen. Yes, increasing thrust can sometimes get you out of a stall but it is easier and safer to just push the nose down. Let me repeat again that this is the same for most not all of the airliners out there and is not unique to the MAX.

Watch this video from mentour aviation on why the MAX needs the MCAS system.
https://www.youtube.com/watch?v=TlinocVHpzk&
To explain why increased thrust would cause the aircraft to pitch up.
https://www.quora.com/Why-does-a-plane- ... is-reduced
 
barney captain
Posts: 2332
Joined: Tue Nov 06, 2001 5:47 pm

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sun Mar 31, 2019 2:04 am

SheikhDjibouti wrote:
SheikhDjibouti wrote:
Please, PLEASE tell me you are a regular big jet pilot. It doesn't have to be a MAX or even a 737, just any transport category aircraft with jet engines and a swept wing.

I have been asking for such an answer for days now, and all I hear is
1) Large jets are stalled all the time / fairly frequently. Or failing that "most airline pilots have done it at some point".

2) They practice stall training on simulators
My point for days now has been that they practice the approach to a stall, and how to avoid entering the stall.
The fact that in 2013 the FAA invited sim manufacturers to introduce full stall capability to their sims tells us it didn't exist before.

3) Stall are easy; I've done them 100's of times. (sotto voce ...in a Cessna)
By the time a pilot gets to a commercial flight deck they should have done this at least 100 times


I want to hear from a 737 or A320 pilot, not a test pilot, not a CFI, not a senior check pilot, not an ex-military fast jet ace. Just an ordinary 737 or A320 pilot.

Have you ever stalled a 737 or A320 with or without passengers, and is it considered routine procedure?

So, morrisond & osiris30 - have you? You have both fought tooth & nail on this issue as if you have some special insight into this matter. :scratchchin:


barney captain wrote:
Maybe I can help -

You would never practice any stall maneuver in a 737 (testing certification notwithstanding).

You DO practice stalls while working on your ratings in smaller GA aircraft - quite regularly.

Up until last year in the US, we routinely practiced approach to stall maneuvers in the sim.

Starting last year, the FAA mandated advanced maneuvering training that requires us to fully stall the aircraft at both low and high altitudes and practice recovery. Again, in the sim only.

Thank you so much. (assuming that you are qualified to comment....)

(I'm not doubting it one iota, but since I queried those who argued against me, I shouldn't automatically accept you simply because you confirm everything I said :lol: )


No problem.

Current 737 CA, 15,000 hrs on type. ;)
Southeast Of Disorder
 
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SheikhDjibouti
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sun Mar 31, 2019 2:16 am

barney captain wrote:
Current 737 CA, 15,000 hrs on type. ;)


Hugely humbled, and grateful for your indulgence.

Me? Big fat zero hours on type, and the last stall training I did was so long ago that the logbook entry was in latin, and my check pilot was Daedulus.
Nothing to see here; move along please.
 
speedking
Posts: 141
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sun Mar 31, 2019 3:51 am

SheikhDjibouti wrote:
barney captain wrote:
Current 737 CA, 15,000 hrs on type. ;)


Hugely humbled, and grateful for your indulgence.

Me? Big fat zero hours on type, and the last stall training I did was so long ago that the logbook entry was in latin, and my check pilot was Daedulus.


You guys getting married or what?
 
barney captain
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Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sun Mar 31, 2019 5:26 am

speedking wrote:
SheikhDjibouti wrote:
barney captain wrote:
Current 737 CA, 15,000 hrs on type. ;)


Hugely humbled, and grateful for your indulgence.

Me? Big fat zero hours on type, and the last stall training I did was so long ago that the logbook entry was in latin, and my check pilot was Daedulus.


You guys getting married or what?


Let's hope not - lol!

But the props from the Zappa fan are certainly appreciated. ;)
Southeast Of Disorder
 
RickNRoll
Posts: 1868
Joined: Fri Jan 06, 2012 9:30 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sun Mar 31, 2019 5:36 am

Pluto707 wrote:
The crucifixion has started, Boeing will suffer !! https://www.abc.net.au/news/2019-03-29/ ... h/10951772
They won't have a problem finding experts who can point out the flaws in MCAS and the self certification
Last edited by RickNRoll on Sun Mar 31, 2019 5:36 am, edited 1 time in total.
 
RickNRoll
Posts: 1868
Joined: Fri Jan 06, 2012 9:30 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sun Mar 31, 2019 5:42 am

Etheereal wrote:
Let me make something clear, since it seems im not being understood properly. I'm not comparing the 330 series with the Max. Someone on the last 5 pages said something that there was ONLY one documented case of the A3XX series where the "sensors" all became unreliable, which im trying to say its false as there are at least 2 more examples, including AF447.

They lost AoA protection because if the ADIRS hadnt frozen and mismatched each other, then they wouldnt have been able to get that 35-45° pitch up angle they ended upon.
There are multiple events for Airbus planes where there has been unreliable airspeed. All the rest followed documented procedure and lived.

MCAS was not documented and not trained for.
 
RickNRoll
Posts: 1868
Joined: Fri Jan 06, 2012 9:30 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sun Mar 31, 2019 5:45 am

dragon6172 wrote:
SheikhDjibouti wrote:
This pitching up when applying power is partly due to the sheer power of the engines, and partly due to their positioning. Particularly in the MAX.

In fact, aren't we now coming full circle, back to part of the reason for MCAS in the first place - to mitigate against the natural tendency of a 737 MAX to pitch up when applying power as a natural reaction to avoid the early onset of a stall.



MAX engines only have a slight increase in power over NG (about 700 lb thrust more) and are not slung lower than those on the NG. The pitch up tendency that MCAS is installed to prevent comes from the fact that the LARGER NACELLES create lift when the aircraft angle of attack is above a certain amount. Because the nacelles are forward of the CG this lift causes a pitch up moment.

This has been covered at least 100 times between the three main MAX threads.


Yes. Their position more forward of the CG.
 
flybucky
Posts: 376
Joined: Tue Apr 17, 2018 7:44 pm

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sun Mar 31, 2019 7:11 am

From WSJ article https://www.wsj.com/articles/the-final- ... 1553876300

Something almost immediately went wrong. At 8:39, as the jet reached an altitude of 8,100 feet above sea level, just 450 feet above ground [see note below], its nose began to pitch down.

[First Officer] Mr. Mohammed radioed the control tower, his crackling voice reporting a “flight-control problem.” The tower operators asked for details as [Captain] Mr. Getachew, a veteran with 8,000 flight hours, fought to climb and correct the glide path. By 8:40, the oscillation became a wild bounce, then a dive.

“Pitch up, pitch up!” one pilot said to the other, as the Boeing jet accelerated toward the ground. The radio went dead.

A note regarding the altitudes: I believe they are incorrect. The 8100 ft at 8:39am is the Pressure Altitude. I believe the writers treated 8100 ft as the true altitude and subtracted the ground elevation to arrive at the 450 ft AGL number. They should have used the corrected altitude = Pressure Altitude + 473 ft, which would give 8573 ft AMSL, and 923 ft AGL, when the nose started to pitch down. (Although a minute later at 8:40am, according to my calculations, it did reach as low as 225 ft AGL. viewtopic.php?f=3&t=1417519&start=2500#p21190407 )
 
Noshow
Posts: 1482
Joined: Wed Jun 15, 2016 3:20 pm

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sun Mar 31, 2019 7:30 am

So the FDR data is leaked now to the US media while Ethiopia is working on the report? That is not good. Isn't that putting them under pressure to come up faster with their report? They will need as long as it takes.
 
XRAYretired
Posts: 870
Joined: Fri Mar 15, 2019 11:21 am

Re: Ethiopian Airlines 737MAX crashes enroute to Nairobi

Sun Mar 31, 2019 8:31 am

Noshow wrote:
So the FDR data is leaked now to the US media while Ethiopia is working on the report? That is not good. Isn't that putting them under pressure to come up faster with their report? They will need as long as it takes.
[photoid][/photoid]

Jumping a little here. I dont believe the FDR has been leaked. The data referred to in the WSJ report would appear to be consistent with the FR24 data available since day one and ends a couple of minutes before the impact. Suspect the before diving bit is just jounalistic flourish. There have been perhaps some leaks from unattributed US sources but, perhaps, no more significant than the EA CEO going on TV saying what he knew.

Ray

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