Ethiopian Airlines flight to Nairobi crashes with 'no survivors' of 157 people aboard

Caporegime
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The FAA is investigating another incident involving a 737.

HOUSTON — Federal authorities say a United Airlines flight declared an emergency when an engine shut down as the plane descended into Houston.

Flight 1168 was carrying 174 passengers and six crew members late Sunday when the engine trouble began near George Bush Intercontinental Airport. The Boeing 737-900 was traveling from Newark Liberty International Airport in New Jersey.

(Source).
 
Soldato
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Post 2 may have a point, modern flight crews have become complacent, reliant on technology and auto systems, when the system malfunctions their inability
to assess the situation, take action, and bring the plane under control has been highlighted.

The report on the crash of Air France 447 is highly critical of the actions [ or complete lack of ] of the crew:
  • the crew made inappropriate control inputs that destabilized the flight path;
  • the crew failed to follow appropriate procedure for loss of displayed airspeed information;
  • the crew were late in identifying and correcting the deviation from the flight path;
  • the crew lacked understanding of the approach to stall;
  • the crew failed to recognize the aircraft had stalled and consequently did not make inputs that would have made it possible to recover from the stall.[215]
Sometimes it's not the plane's fault.

Yikes.....

A long list of failings there. Remind me not to ever fly with Ethiopian Airlines...

Edit: Air France
 
Associate
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Probably worth making a couple of points here.

Altought its true that the majority of airline accidents cite pilot error as a causal factor, if you drill down into the details it seems clear that fatigue is a major factor in these errors. It may be that the image of an airline pilot is of an overpaid prima dona who does'nt do any work, sadly this is'nt true. The fact you can sometimes fly across europe for 20 quid means airlines tighten the screws wherever they can - rostering practices are one area where this holds true. Airline pilots fall asleep at the controls more often that you might care to imagine.

As a side note - if you automate everything then 100% of all accidents will be down to the automation.

Regarding AirFrance, its very easy in the cold light of day to point out the numerous errors that were made. One thing I can garantee is that those guys didn't set out that day to kill themselves and all on board. One of the things I remember from reading either the accident report or documents relating to it was that the crew thought the aircraft couldn't be in a stall because it was impossible to stall an Airbus. Certainly training was an issue there, but I wonder how much Airbus sold their wundermachine on the basis of how much protection it gave the pilot.

As regards to the current accident, there is no information yet. Nontheless it seems very similar to Lionair. The cause of that accident hasn't been verified either, but a prelimary report has been released. If the suspicions in that case hold true then it would seem that the failure of a single sensor (Angle of Attack vane) led to a cascade of failures the least obvious of which is that the aircraft pushes the nose down using the stabiliser trim system. And it can very quickly do so to such an extent that it overpowers the pilots ability to pull the nose back up using the control column. If that turns out to be true then it is definately an aircraft design problem.
 

B&W

B&W

Soldato
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Probably worth making a couple of points here.

Altought its true that the majority of airline accidents cite pilot error as a causal factor, if you drill down into the details it seems clear that fatigue is a major factor in these errors. It may be that the image of an airline pilot is of an overpaid prima dona who does'nt do any work, sadly this is'nt true. The fact you can sometimes fly across europe for 20 quid means airlines tighten the screws wherever they can - rostering practices are one area where this holds true. Airline pilots fall asleep at the controls more often that you might care to imagine.

As a side note - if you automate everything then 100% of all accidents will be down to the automation.

Regarding AirFrance, its very easy in the cold light of day to point out the numerous errors that were made. One thing I can garantee is that those guys didn't set out that day to kill themselves and all on board. One of the things I remember from reading either the accident report or documents relating to it was that the crew thought the aircraft couldn't be in a stall because it was impossible to stall an Airbus. Certainly training was an issue there, but I wonder how much Airbus sold their wundermachine on the basis of how much protection it gave the pilot.

As regards to the current accident, there is no information yet. Nontheless it seems very similar to Lionair. The cause of that accident hasn't been verified either, but a prelimary report has been released. If the suspicions in that case hold true then it would seem that the failure of a single sensor (Angle of Attack vane) led to a cascade of failures the least obvious of which is that the aircraft pushes the nose down using the stabiliser trim system. And it can very quickly do so to such an extent that it overpowers the pilots ability to pull the nose back up using the control column. If that turns out to be true then it is definately an aircraft design problem.

You said you fly the Max, if this sensor failure happened to you what would you do to correct it?
 
Associate
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If the AoA vane failed a number of things would happen.

The most obvious is that the airspeed indicator and a number of other flight instruments would fail. In addition the stick shaker would start operating. This a very loud electric motor which rattles the control column and most definately gets your attention. The high speed warning horn will also start sounding, in addition to a aural warning stating "SPEED LOW SPEED LOW". Its a very confusing situation which can easily mask the fact that the aircraft is trimming the nose towards the ground. If this happens the aircraft is probably at some point going to start shouting "TERRAIN TERRAIN PULL UP". The point I'm trying to make is that its going to happen very suddenly and be very confusing to try and sort out what's going on.

Actually to initally solve the problem you should, in simple terms:

Pitch the nose to 10 degrees above the horizon.
Apply 80% N1 (the primary power setting parameter for the engine), or at least leave the thrust levers where they are if taking off.
(or 4 degrees/75% N1 depending on aircraft configuration)
The above should ensure the aircraft remains flying.

Reach over by the thrust lever and toggle the stabiliser trim cutout switches.
This should disable the stabilser trim system and stop the aircraft trimming the nose down. You would have to use the manual trim system for the remainder of the flight.

Which sounds easy but what I want to stress is how confusing the situation is going to be initally - a lot of warning systems are going to going off, giving contradictory information and not a lot of time to recognise and fix the problem.

To put it another way, there are two checklists we have in the flightdeck which are relevant.

Airspeed unreliable and Runway stabiliser trim. The trick is you really need to do both at the same time and in a short time.

Please note however that the failure of both the Lionair and Ethiopian aircraft have not been proven to be activation of the stab trim (MCAS) system, however if it is the case, the above is what I would do.
 
Soldato
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Great posts in this thread esmozz.
With no concrete information to go on for both accidents, how do you feel having to pilot one of these planes?

As an ignorant passenger, I'd be thinking twice about flying in one of these. Statistics say it's safe, but hysteria is powerful.
Might be a very stupid question, but do you go through any sort of training for how to maintain a sound mind in this scenario?
 
Soldato
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I read earlier that the MCAS system used to be over-ridden by manual inputs, but with the Max that changed. Now, the system has to be disabled before it stops interfering, but Boeing didn't initially update their manuals to mention this fact. That would have a significant impact on pilot reaction, surely?
 
Soldato
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Everyone who is scared of flying thinks its the landing that's the worst, Its the taking off that's the most shady part a plane full of fuel crashing = death.

RIP to everyone.
 
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Man of Honour
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Out of interest can pilots refuse to fly an aircraft if they don't feel it's safe?

Obviously not in terms of obvious mechanical problems or weather, but in the case of the 737 MAX, if they're being grounded elsewhere is this enough for a pilot to refuse to fly one? I know tube drivers are able to refuse to drive a train if they feel it's unsafe or there's a fundamental issue that's not been addressed.
 
Associate
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I read earlier that the MCAS system used to be over-ridden by manual inputs, but with the Max that changed. Now, the system has to be disabled before it stops interfering, but Boeing didn't initially update their manuals to mention this fact. That would have a significant impact on pilot reaction, surely?

This is largely true, actually MCAS doesn't exist on earlier variants of the B737. In fact, Boeing not only didn't update their manuals, they neglected to tell pilots that the system actually exists.

Great posts in this thread esmozz.
With no concrete information to go on for both accidents, how do you feel having to pilot one of these planes?

As an ignorant passenger, I'd be thinking twice about flying in one of these. Statistics say it's safe, but hysteria is powerful.
Might be a very stupid question, but do you go through any sort of training for how to maintain a sound mind in this scenario?

Thanks. Not hugely worried about flying the Max but it is at the back of my mind. My company operate a mixed fleet of B737 and I'm flying older variants for the remainder of the month - I'm quite okay with that ;). Regarding training, I guess the only thing to fail back on to try to remain calm is experience, certainly I've never had specific training in that regard. As you build your career as a civilian pilot you will exposed to a variety of different situations, first on light aircraft, then as a first officer, then (in my case) as a captain on smaller aircraft and working your way up. Hopefully by the time the brown stuff really hits the fan and you're in charge, you should be comfortable enough (and experienced enough) in your environment to be able to remain calm. Doesn't always work that way.

As an aside, I laughed when I watched Sully, the movie. One pilot calmly remarks to the other that one engine has gone, then calmly remarks that the other engine has gone. In real life I suspect the air turned blue in that flight deck. It certainly would in mine under the same circumstances.

Out of interest can pilots refuse to fly an aircraft if they don't feel it's safe?

Obviously not in terms of obvious mechanical problems or weather, but in the case of the 737 MAX, if they're being grounded elsewhere is this enough for a pilot to refuse to fly one? I know tube drivers are able to refuse to drive a train if they feel it's unsafe or there's a fundamental issue that's not been addressed.

Unfortunately, no. The decision to ground an aircraft under these circumstances is taken at a much higher level within the flight operations department. An individual pilot who decided not to fly the Max based on it being grounded elsewhere would probably find themselves in hot water. Thats not to say you can't refuse to fly a particular aircraft based on its fit or a previous maintance action. You can, you just better have a good reason.
 
Soldato
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I assume if this all happened at night you'd be in even more trouble. Then again it might be better not seeing the ground getting closer. :(
 
Associate
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I assume if this all happened at night you'd be in even more trouble. Then again it might be better not seeing the ground getting closer. :(

Yes, you would be. Or in cloud/bad weather. You would have to rely entirely on your instruments and although this particular failure wouldn't affect your artifical horizon you might not entirely trust it if you can't figure out what's going on, leading to even more confusion.
 
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