Ethiopian plane crash
Discussion
Ffs ptb we need an autopilot version of you in every max so that with 3000ft to play with, high altitude take off with everything fubar you could make sure every simple tick box step is followed in the manual ONCE you’ve diagnosed an aoa failure WITHOUT any aoa data on the cluster
Are you Jim Lovells ghost?
Are you Jim Lovells ghost?
Ptb,
I have only skimmed through your posts here,
I find myself agreeing with much of what you have said, and the questions you are asking.
Always good to have the knowledge from someone like yourself on these topics so we can reflect.
All the best.
I have only skimmed through your posts here,
I find myself agreeing with much of what you have said, and the questions you are asking.
Always good to have the knowledge from someone like yourself on these topics so we can reflect.
pushthebutton said:
What I'm attempting to show is that the statement by the ECAA, that said that the pilots followed Boeing's guidelines, is at best misleading. It really depends on when and how the appropriate checklists were actioned and, possibly, if even at all. What has happened is, as a result of the preliminary report, judge, jury and executioner have already acted and the actual causes are of little relevance: consequentially, the opportunity to learn from the accidents will potentially be diminished.
Very much this, All the best.
George Smiley said:
Ffs ptb we need an autopilot version of you in every max so that with 3000ft to play with, high altitude take off with everything fubar you could make sure every simple tick box step is followed in the manual ONCE you’ve diagnosed an aoa failure WITHOUT any aoa data on the cluster
Are you Jim Lovells ghost?
George calm down. You’re ranting now.Are you Jim Lovells ghost?
As pushthebutton has explained many times it’s actually just two non normal checklists. Unreliable airspeed and stabiliser runaway. Boeing had pointed this out in a bulletin after the first crash.
Yes of course it’s difficult when you don’t expect it and there are stall warnings etc going off.
It’s certainly not a combination of events that’s uncontrollable though.
As I said before, I think it’s Boeing’s fault that this happened but other pilots may disagree or like pushthebutton is, simply ask more about what the pilots were actually doing to resolve it.
pushthebutton said:
You’re focusing solely on the MCAS aspect of the accident and ignoring the initial failure, which was related to AoA.
60s elapsed between lift off and the beginning of the Flap retraction which ultimately led to MCAS activating incorrectly.
Surely a valid point is that the pilots had been trained, but without the knowledge that flap retraction activates MCAS; and that setting flaps again would stop the MCAS problem happening? That's my understanding anyway.60s elapsed between lift off and the beginning of the Flap retraction which ultimately led to MCAS activating incorrectly.
pushthebutton said:
Lots of interesting stuff.
Do you think that an over reliance on automation has contributed to these accidents?It seems (and may be utter crap) that the airlines that have flown around these problems are the sort of airlines that train more “stick flying” and the ones that have had issues are perhaps more keen on automated flight? Maybe crews reluctant to turn off automatic featur3s and just fly the plane.
pushthebutton said:
skwdenyer said:
All good stuff...
Once the airspeed issue was dealt with (or not) they seem to have followed the AD and the runaway trim checklist, but got nowhere.
Just this bit.Once the airspeed issue was dealt with (or not) they seem to have followed the AD and the runaway trim checklist, but got nowhere.
It really depends when and how the checklist was actioned, the state of trim of the aircraft at the time the switches were placed to cutout and the use of the electric trim up to that point. Too many variables to say that they got nowhere with the checklist as it does assume that you continue to fly with reference to valid datums.
One interesting point from the preliminary report - if you look at the trim state line from after they set stab trim cutout, there seem to be "perturbations" for want of a better word, movements that don't - to my eye - seem to be there previously. The resolution of the graph is rubbish, but those movements might support the contention that the stabilizers were not responding to (attempted) manual inputs. That would seem to me to fit with the airspeed at that point being already very high.
For my mind, a lot rests on what the state of the instruments was at the start - if airspeed was consistent and no IAS DISAGREE was showing early on, it seems plausible to imagine the crew didn't believe they had an unreliable airspeed, leading them to instead consider the AD (as it would no doubt have been front of mind).
The other interesting thing is that - again from the graphs - it seems that the rate of winding ANU in response to yolk trim switches is slower than the rate of winding AND in response to MCAS. Not a biggie - one would imagine a look at the indicator would sort it out - but interesting nonetheless that "n" seconds one way is not the same as "n" seconds the other.
Final point on the graphs - at one stage it looks like the FCC was commanding both AND and ANU at the same time - or am I mis-reading that?
768 said:
Read something today, probably covered already, suggesting that the AoA was suddenly being reported as 70 degrees when it "failed". And that anything above 25 isn't something MCAS is going to recover, so just a simple extra conditional on an if statement could have prevented it.
One can equally imagine a check along the lines of "if AoA jumps 70 degrees in a microsecond then there's an error" but one has to be very careful to not filter out genuine events with strange transient readings.montymoo said:
Very much this,
All the best.
Not really, for me. The accusation is that the ECAA is lying, and I don't think there is any evidence of that at this stage. I don't think anybody is questioning his technical knowledge or experience.All the best.
Use of the phrase 'is at best misleasding' is, in my view, at best misleading. I wouldnt have disagreed with 'could be misleading'.
Edited by hutchst on Thursday 11th April 03:31
George Smiley said:
Ffs ptb we need an autopilot version of you in every max so that with 3000ft to play with, high altitude take off with everything fubar you could make sure every simple tick box step is followed in the manual ONCE you’ve diagnosed an aoa failure WITHOUT any aoa data on the cluster
Are you Jim Lovells ghost?
Jim Lovell had several hours and a backup team to prevent a Apollo 13 disaster.Are you Jim Lovells ghost?
PTB would be ‘Super Lovell’ - able to diagnose all the issues and execute the exact corrective sequence at first attempt ... while knowing you may be dead in less than a minute ... a super skill set.
The ET pilots were obviously rank amateurs
.. nothing wrong with the plane
alfaman said:
George Smiley said:
Ffs ptb we need an autopilot version of you in every max so that with 3000ft to play with, high altitude take off with everything fubar you could make sure every simple tick box step is followed in the manual ONCE you’ve diagnosed an aoa failure WITHOUT any aoa data on the cluster
Are you Jim Lovells ghost?
Jim Lovell had several hours and a backup team to prevent a Apollo 13 disaster.Are you Jim Lovells ghost?
PTB would be ‘Super Lovell’ - able to diagnose all the issues and execute the exact corrective sequence at first attempt ... while knowing you may be dead in less than a minute ... a super skill set.
The ET pilots were obviously rank amateurs
.. nothing wrong with the plane
Bit in bold sounds like an engine failure at V1 to me. Every commercial pilot has to display proficiency in that.
It may surprise you to know that I didn't write the checklists in much the same way as Jim Lovell didn't. There was a whole team at Boeing...etc etc. What Jim did do was to action 'the exact corrective sequence' as prescribed by NASA.
We don't know whether the Ethiopian crew did at this point in time as not enough information has been released even though the preliminary report suggests they did. I'm suggesting that that report is missing a important detail and may be motivated by something other than establishing all aspects of the cause.
pushthebutton said:
We don't know whether the Ethiopian crew did at this point in time as not enough information has been released even though the preliminary report suggests they did. I'm suggesting that that report is missing a important detail and may be motivated by something other than establishing all aspects of the cause.
I think a lot of the missing data is on the voice recorder. I don't think we've had information on that yet?The data tells us what was done. We know what situation they were put in by the plane. We can see their actions in response to that. But we don't know all of the why. We don't know if some sequence of alarms triggered an incorrect response or thought process for the pilots. Were they fighting to follow the list but found themselves physically unable for some reason? Who knows.
I think the one thing we do know, is that MCAS took an action it should not have done if it had been built properly, which it wasn't. This put the plane and the pilots into a needlessly dangerous situation.
The question based on that alone is how did such a poor quality design make it into a brand new aircraft? Followed up by how do we stop it again, and should anybody be punished as part of that process?
Even if the pilots could have done better. Some people at Boeing and/or the FAA, put the pilots and passengers into a high stress situation that should never have happened. This wasn't an issue caused by the pilots doing something wrong.
Paraglider pilot here (and a rusty one at that), so I'm clearly not an expert on modern airliners . . .
. . . but puzzled that Pitch / Attitude isn't as significant an input as AoA? I understand that Pitch and AoA are never(?) going to be the same, and that it's AoA that matters in terms of lift vs drag, BUT surely there's a close relationship (with airspeed as a variable)?
. . . but puzzled that Pitch / Attitude isn't as significant an input as AoA? I understand that Pitch and AoA are never(?) going to be the same, and that it's AoA that matters in terms of lift vs drag, BUT surely there's a close relationship (with airspeed as a variable)?
Octoposse said:
Paraglider pilot here (and a rusty one at that), so I'm clearly not an expert on modern airliners . . .
. . . but puzzled that Pitch / Attitude isn't as significant an input as AoA? I understand that Pitch and AoA are never(?) going to be the same, and that it's AoA that matters in terms of lift vs drag, BUT surely there's a close relationship (with airspeed as a variable)?
Difficult to control pitch when airplane doing it's best to throw itself into the ground pointy end first.. . . but puzzled that Pitch / Attitude isn't as significant an input as AoA? I understand that Pitch and AoA are never(?) going to be the same, and that it's AoA that matters in terms of lift vs drag, BUT surely there's a close relationship (with airspeed as a variable)?
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