Go Back  PPRuNe Forums > Flight Deck Forums > Rumours & News
Reload this Page >

Ethiopian airliner down in Africa

Rumours & News Reporting Points that may affect our jobs or lives as professional pilots. Also, items that may be of interest to professional pilots.

Ethiopian airliner down in Africa

Old 27th Apr 2019, 18:29
  #4441 (permalink)  
 
Join Date: Jan 2004
Location: Far West Wessex
Posts: 2,556
So as this thread continues towards the five-grand mark, how many of these posts have been a version of "well, if this had happened to me and my F/O, we'd have done this, that and those other things and everyone would have been fine because FLY THE AIRPLANE and BASIC AIRMANSHIP and we're not children of the magenta line, we're hairy-armed master aviators."

But let's get this straight. It never happened to you.

There are three pilots alive to whom this failure (AoA failure arms MCAS, which kicks in as flaps retract) actually happened. Four others are dead along with their passengers, The failure caused two fatal accidents less than two years after service introduction. Compare this to anything in the past 25 years of aviation and tell me that's not unusual, that the AoA/MCAS sequence is something that should be handled with normal training.

Bull!
LowObservable is offline  
Old 27th Apr 2019, 18:43
  #4442 (permalink)  
 
Join Date: Oct 2011
Location: Lower Skunk Cabbageland, WA
Age: 71
Posts: 355
Originally Posted by LowObservable View Post
Compare this to anything in the past 25 years of aviation and tell me that's not unusual, that the AoA/MCAS sequence is something that should be handled with normal training.

Bull!
What about the 737 rudder problems [hardovers from defective actuators]? IIRC, that problem, besides a mechanical one, had to be "trained" for a technique to avoid going splat.

But the guy you're railing against, the one who keeps on saying, "Fly the airplane," DOES acknowledge the design problem generated by Boeing, in every post, while criticizing the pilots. That IS a balanced view.

Organfreak is offline  
Old 27th Apr 2019, 18:57
  #4443 (permalink)  
 
Join Date: Jun 2009
Location: Tennessee, USA
Age: 69
Posts: 1
I just saw this on The Aviation Herald:

On Apr 27th 2019 it became known, that four independent whistleblowers, current and former Boeing employees, had called the FAA hotline for whistleblowers regarding aviation safety concerns on Apr 5th 2019. The concerns reported were wiring damage to the AoA related wiring as result of foreign object damage as well as concerns with the TRIM CUTOUT switches. The FAA believes these reports may open completely new investigative angles into the causes of the two crashes in Indonesia and Ethiopia.
dccraven is offline  
Old 27th Apr 2019, 18:59
  #4444 (permalink)  
 
Join Date: Aug 2017
Location: London
Posts: 94
Originally Posted by 737 Driver View Post
By the numbers then: Stick shaker. WTF?! Check my power (increase as necessary), check my attitude, check my configuration. Is it flying or is it wallowing? If it is wallowing, keep the nose down and accelerate. If its flying, probably a false indication, continue the climb, call for the gear. Cross check instruments. I've got my hands full, so ask my FO to read off what he sees on all three airspeeds. At 400 feet check my roll mode, have FO ask for straight ahead if appropriate and declare emergency. If by now I've determined we have unreliable airspeed, memory items except I'm going to keep takeoff power and 15 degrees pitch until 1000' where I set 10 degrees and 80% N1.
Very convincing, well written, and no-one can argue that following that recipe would have saved the aircraft.

There are two problems with it. The pilot seems to have done rather a lot by 400ft. And leaving flaps down seems a bit too convenient. If you just add a bit of delay in pulling the stick shaker CBs, and you happen to clean up (which would be perfectly good airmanship), then the MCAS genie is out of the bottle and you're in test pilot mode.

Reality is more complex, time is more flexible, cognitive skills are worse than the scripts that we write after the event.

A competent pilot showing good airmanship would most likely have activated mcas pre lion air, and quite possibly post. Once in the mcas trap I'd say it's 50/50 they'd get out of it at low altitude. See my previous post for why. So your constant assertions of 'just fly the plane' don't really cut it.

Again I think everyone agrees with you that there needs to be more emphasis on hand flying skills throughout the whole industry and that 200h is ludicrous for a FO.

Last edited by PerPurumTonantes; 27th Apr 2019 at 22:03.
PerPurumTonantes is offline  
Old 27th Apr 2019, 19:09
  #4445 (permalink)  
 
Join Date: Nov 2007
Location: Canada
Posts: 24
One thing is certain, the persons who are the main drivers of these accidents had a lot more time to consider the outcome of their actions than the pilots. They have a CPA, MBA and/or JD. They received large salaries and bonuses. They live in the suburbs of Chicago, and will be receiving far less scrutiny than the engineers and pilots. They will cost out the lives lost vs. the cost of doing things properly. Their profession will insulate them from their true share of the culpability. In the end a very few will get a golden handshake and pursue other interests. Letís take a minute to remember them.

Last edited by dozing4dollars; 27th Apr 2019 at 19:56.
dozing4dollars is offline  
Old 27th Apr 2019, 19:46
  #4446 (permalink)  
 
Join Date: Nov 2007
Location: Canada
Posts: 24
.... and now, because this is a pilots forum, the subject of Airspeed. Although a lot was going on, it seems to me, sitting on my couch, that if A/S was controlled, the misbehaviour of the trim would have been easier to deal with at a lower A/S.

The previous LionAir flights controlled A/S (obviously). When we ďhand flyĒ (flight directors and auto throttle on) itís analogous to me on my couch. Fly toward the FD. Hell, I even have a Heads Up display. If you want to see the other guys squirm, turn off the AT Much of this so-called ďhand flyingĒ isnít really. I think it would be very human to miss the AS during an event such as this. I think pulling the throttles back once unreliable AS was identified would be key to gaining some time to think. Hand flying with AT on isnít doing much good and has made me less aware of flying using the throttles.

I also believe the MCAS was not adjusting its trim input for AS. From what Iíve read in the discription of MCAS, it shouldnít have been using 2.5 degree ANU at higher AS
dozing4dollars is offline  
Old 27th Apr 2019, 19:51
  #4447 (permalink)  
 
Join Date: Nov 2006
Location: Europe
Posts: 668
200 hour FOs? A culture of maximum automation at all times with almost zero handflying experience and confidence?

Sounds more like Europe than Africa.

​​​
Kerosine is offline  
Old 27th Apr 2019, 19:55
  #4448 (permalink)  
 
Join Date: Apr 2019
Location: USA
Posts: 217
Originally Posted by LowObservable View Post
But let's get this straight. It never happened to you.
True, none of us were there when the pins all lined up. Guilty as charged.

Might I also point out that none of us were there when the aircraft designers were designing, the project managers were managing, the regulators were regulating, and the airlines were training. Yet, there seems to be a pretty broad consensus in these parts that their were critical lapses in those parts despite the fact that no one here (at least that I've seen) has claimed to be current in qualified in those specialties. Odd, don't you think?

No, I was not there, and no I have never seen an MCAS failure in the sim or in life. However, over the course of 35+ years in aviation and perhaps a dozen different aircraft, I've dealt with more emergencies in the sim than I can count and more in the air than I ever wished to have had. I've encountered pilots of all different skill levels, and I've observed the traits that separate the good from the bad. Having reviewed perhaps hundreds, if not thousands, of incident reports over the years, I think I have a fairly good sense for what types of malfunctions should have been survivable without resort to extraordinary means, which ones required some combination of luck and superior skill, and which ones were pretty much hopeless from the start. In the case of Lion Air, I'd put that one somewhere between the first and second categories mainly due to the novelty. For Ethiopian, that one falls squarely in the first batch. Sorry you disagree, but I strongly suspect the final accident reports will fall closer to my position than yours.

Last edited by 737 Driver; 27th Apr 2019 at 21:57.
737 Driver is offline  
Old 27th Apr 2019, 20:39
  #4449 (permalink)  
 
Join Date: May 2010
Location: Boston
Age: 70
Posts: 443
Originally Posted by 737 Driver View Post
Having reviewed perhaps hundreds, if not thousands, of incident reports over the years, I think I have a fairly good sense for what types of malfunctions should have been survivable without resort to extraordinary means, which ones required some combination of luck and superior skill, and which ones were pretty much hopeless from the start. In the case of Lion Air, I'd put that one somewhere between the first and second categories mainly due to the novelty. For Ethiopian, that one falls squarely in the first batch. Sorry you disagree, but I strongly suspect the final accident reports will fall closer to my position than yours.
In the Ethiopian case unfortunately I would have to disagree with you, the chances of an unbiased look at pilot actions and training are low given the response to the prior (Lebanon) accident report which detailed numerous pilot errors, with a possibility of subtle PIC incapacitation to which Ethiopian authorities strongly objected and proposed unsupported by facts alternate theories.

This illustrates yet another factor of national/corporate pride hindering global safety objectives, and yes Boeing/FAA are in same category.
MurphyWasRight is offline  
Old 27th Apr 2019, 21:04
  #4450 (permalink)  
 
Join Date: May 2004
Location: Москва/Ташкент
Age: 51
Posts: 864
Originally Posted by dozing4dollars View Post
One thing is certain, the persons who are the main drivers of these accidents had a lot more time to consider the outcome of their actions than the pilots. They have a CPA, MBA and/or JD. They received large salaries and bonuses. They live in the suburbs of Chicago, and will be receiving far less scrutiny than the engineers and pilots. They will cost out the lives lost vs. the cost of doing things properly. Their profession will insulate them from their true share of the culpability. In the end a very few will get a golden handshake and pursue other interests. Letís take a minute to remember them.
And ain't that the truth.
flash8 is offline  
Old 27th Apr 2019, 21:43
  #4451 (permalink)  
 
Join Date: Apr 2019
Location: USA
Posts: 217
Originally Posted by PerPurumTonantes View Post
There are two problems with it. The pilot seems to have done rather a lot by 400ft.
No more than I do on any other takeoff emergency. I get to practice several of these a year during recurrent training, and it’s a pretty standard drill to focus primarily on these basic parameters until you get some altitude under you.

And leaving flaps down seems a bit too convenient.
It’s more habit than convenience. My general practice on any takeoff emergency is to leave some flaps hanging unless a procedure calls for otherwise until such time that I determine that I will not be returning to the departure field. This slows things down considerably and burns fuel quicker.

If you just add a bit of delay in pulling the stick shaker CBs, and you happen to clean up (which would be perfectly good airmanship), then the MCAS genie is out of the bottle and you're in test pilot mode.
Sure, I’ll play along. Of course, you’ll have to assume I haven’t put on the A/P by now, and since I’ve pulled the stick shaker circuit breaker (not procedure, BTW, but I’d be inclined to do it anyway) and finished the Airspeed Unreliable NNC, there would be no reason not to ask HAL for some assistance. So, there I am hand-flying, bring the flaps up, and BAM!, MCAS kicks in. What MCAS will then attempt to do is run the trim nose down for 9 continuous seconds and spin the trim wheel about 37 times. I’ve asked this before, and I’ll ask this again: Starting from a stabilized, in-trim platform, exactly how long should a qualified 737 type-certified Captain who is hand-flying the aircraft let the trim run in one direction before he/she does something about it?

Therein lies your answer. What you have at this point is runaway stab trim. Our procedures really don’t care what the source of the runaway is. If you have an undesired and unexplained stab trim input, you are expected to intervene.

Reality is more complex, time is more flexible, cognitive skills are worse than the scripts that we write after the event.

Again I think everyone agrees with you that there needs to be more emphasis on hand flying skills throughout the whole industry and that 200h is ludicrous for a FO.
I do not disagree, but there really is a limit to how much befuddlement should be expected of a professional flight crew entrusted with the lives of 150+ souls. If a pilot cannot overcome the initial surprise factor in pretty short order, fall back on basic airmanship skills and execute known procedures, then perhaps they should reconsider their chosen career.



Last edited by 737 Driver; 27th Apr 2019 at 22:45.
737 Driver is offline  
Old 27th Apr 2019, 21:56
  #4452 (permalink)  
 
Join Date: Mar 2018
Location: Central UK
Posts: 568
Originally Posted by 737 Driver View Post
So, there I am hand-flying, bring the flaps up, and BAM!, MCAS kicks in. What MCAS will then attempt to do is run the trim nose down for 9 continuous seconds and spin the trim wheel about 37 times. Iíve asked this before, and Iíll ask this again: Starting from a stabilized, in-trim platform, exactly how long should a qualified 737 type-certified Captain who is hand-flying the aircraft let the trim run in one direction before he/she does something about it? Therein lies your answer. What you have at this point is runaway stab trim. Our procedures really donít care what the source of the runaway is. If you have an undesired and unexplained stab trim input, you are expected to intervene.



I do not disagree, but there really is a limit to how much befuddlement should be expected of a professional flight crew entrusted with the lives of 150+ souls. If a pilot cannot overcome the initial surprise factor in pretty short order, fall back on basic airmanship skills and executed known procedures, then perhaps they should reconsider their chosen career.
+100
Oh? Ten charaters minimum? +100,000,000 then
meleagertoo is offline  
Old 27th Apr 2019, 22:09
  #4453 (permalink)  
 
Join Date: Feb 2019
Location: shiny side up
Posts: 431
I haven't seen the original reports (would appreciate a pointer to the source if someone has it)
737 Driver ASRS database link.. https://asrs.arc.nasa.gov/overview/database.html
Smythe is offline  
Old 27th Apr 2019, 22:43
  #4454 (permalink)  
 
Join Date: Apr 2019
Location: USA
Posts: 217
Originally Posted by Smythe View Post
737 Driver ASRS database link.. https://asrs.arc.nasa.gov/overview/database.html
Found them, thanks! The reports were misfiled with the 737NG's for some reason. They appear to be reporting the same anomaly. Report numbers are ACN 1597286 and ACN 159380 for anyone looking for them.
737 Driver is offline  
Old 27th Apr 2019, 22:50
  #4455 (permalink)  
 
Join Date: Jun 2003
Location: UK
Posts: 2,560
Originally Posted by rickyricks View Post
OK, first post, and not a pilot. But I have read all posts here. Simple question. If the pilots of Lion Air 610 and Ethiopian Airlines 302 had been flying Airbus A320s would these accidents have happened? I am a frequent passenger (I hate TLAs, especially SLF - we simply pay your wages after all) so I would like to have some objective feedback.
The 737 Max uses one AoA vane, and if it fails a world of hell ensues.

The A320 uses the two best of three vanes, so discarding the faulty one. This makes a fault very unlikely. However, it has happened! 2 froze in a fixed position causing the aircraft to pitch down (it thought those 2 were correct and the 1 truly correct one was incorrect). The pitch down was overcome by the pilots using half backstick. They then worked out the two side by side buttons that needed switching off to correct the situation.

Since then Airbus underwent a huge program to ensure pilots knew how to recognise the problem (you can catch it well well before it pitches you down) and which two buttons to press. Google: OEB48. The issue has now been engineered out and I don't think it happened a second time.

The A320 is a proper FBW aircraft that has been pottering around since the 80s. The max is a conventionally controlled aircraft with a bit of totally inadequate FBW bolted on, to fix a fundamental aerodynamic problem that would be forbidden if the aircraft was new.

And yes, I received sim training to recognise and recover from an OEB48 event.


Incident: Lufthansa A321 near Bilbao on Nov 5th 2014, loss of 4000 feet of altitude
HundredPercentPlease is offline  
Old 27th Apr 2019, 22:50
  #4456 (permalink)  
 
Join Date: Jan 2008
Location: Reading, UK
Posts: 13,270
Originally Posted by Smythe View Post
737 Driver ASRS database link.. https://asrs.arc.nasa.gov/overview/database.html
Report Numbers (ACNs): 1597380, 1597286. Neither was an MCAS-related event; there are none in ASRS.
DaveReidUK is online now  
Old 27th Apr 2019, 23:13
  #4457 (permalink)  
 
Join Date: Aug 2012
Location: Scotland
Age: 51
Posts: 174
Excuse the length & potential ignorance;

I'm still really, seriously struggling to get my head around the specifying of MCAS & it's method of operation. It's apparently there to increase feel at high AOA, but its driving a primary flight control surface. I understand that increasing feel at increasing AOA is necessary for certification requirements & I understand that feel reduces as AOA increases in the MAX due to the additional lift generated by the larger, repositioned engine cowlings.

So, for whatever reason, MAX reaches high AOA which isn't indicated as is normal by stick feel - Pilot needs to be informed of the situation - this part seems to be neglected / skipped & dubious automation takes over & starts driving the big guy at the back. Why does the requirement for increased stick force / feel to the pilot morph immediately into a substantial control surface deflection?

I'm seeing it that MCAS is doing nothing to meet the certification requirements of increasing feel, but rather forcefully avoiding the flight regime where the certification requirement exists - "don't go there" rather than "we are approaching there"


In my simplistic terms, I have a car that has lightening steering input as steering angle increases - it makes it a bit misleading to drive & the feel isn't right;

In my garage & in an ideal world the steering system is redesigned so that it works in the generally accepted manner. In a less ideal world, due to cost or time constraints a damper or progressive restrictor of some form is added. Either will resolve the issue & give the desired feel.

In the Boeing garage, skip the feel issue & add in a hidden & complex system that powerfully steers the car in the opposite direction of what's requested when the steering angle gets high. Control this complexity from a steering angle sensor which is know to be susceptible to damage & occasional failure. This is not adding feel, its taking control & in a questionable manner.

The more that I think about this something tells me that the characteristics of the MAX in the high AOA regime may have more issues than simple feel alone - hence the utilisation of a pile driver to crack what is apparently a nut.
Thrust Augmentation is offline  
Old 27th Apr 2019, 23:56
  #4458 (permalink)  
 
Join Date: Jun 2009
Location: florida
Age: 78
Posts: 1,436
Still confusion about MCAS

Salute!
@Ricky Answer to your original question is easy----- NO!

@Thrust... Great analogy with the power steering. I used that same one with my wife. Last thing I want, and sje agreed, was the power steering to get easier the more I turned the wheel. And the auto folks figured this out back in the late 50's. My first experience with an inlaw's car was a surprise. But within a few years we had better control valve configurations and then some inputs from speed. Hmmmm..... starting to sound like some airplane systems intended to "help" as well as keep the pointy end forward.

Back at Ricky and Thrust........ It ain't "feel". It's the basic aero characteristic of the MAX when at high AoA. So they called it "Maneuvering CHaractersitic .........." Unlike previous versions, this new critter had less inherent aero resistance to increasing AoA than required/desireable. In other words, it could be possible that eventually your AoA might keep increasing while you had the yoke/column/stick neutral. Not good.

The Boeing fix was not to screw with the "feel". Instead, by moving the stab, then the existing flight control stuff could save the day and the plane would pass the certification requirements. Although intended for high altitude and maneuvering flight, the accident MCAS scenarios happened at low altitude and slow speed and at the tail end of a critical phase of flight. Oh yeah........ the damned wheel was shaking like crazy and there were various warning lights.

In the 'bus, there is a last ditch feature called "direct law". So even if the AoA data and air data is FUBAR, your stick movement will command control surface movement at some default ratio. It's like the cable/pulley/pushrod stuff our 737 golden arms talk about. It's like your auto power steering as far as you can tell. And the 'bus is more aerodynamically capable of meetinfg the cert requirements due to its basic design, unlike the new 737 MAX.

Gums.....

Last edited by gums; 28th Apr 2019 at 00:06.
gums is offline  
Old 27th Apr 2019, 23:59
  #4459 (permalink)  
 
Join Date: Feb 2019
Location: shiny side up
Posts: 431
Found them, thanks! The reports were misfiled with the 737NG's for some reason.
There are far more than 2 reports.

The search is tough, one has to search the different variants with what is reported in the ASRS system. (there is no 737-8MAX, etc)
So far, there are reports under, 737-800, B737 Next Generation Undifferentiated, and B737 Undifferentiated or Other Model..

the nomenclature of this model has created some issues.
Smythe is offline  
Old 28th Apr 2019, 00:40
  #4460 (permalink)  
 
Join Date: Aug 2007
Location: Alabama
Age: 56
Posts: 366
Originally Posted by gums View Post
Salute!

In the 'bus, there is a last ditch feature called "direct law". So even if the AoA data and air data is FUBAR, your stick movement will command control surface movement at some default ratio. It's like the cable/pulley/pushrod stuff our 737 golden arms talk about. It's like your auto power steering as far as you can tell. And the 'bus is more aerodynamically capable of meetinfg the cert requirements due to its basic design, unlike the new 737 MAX.

Gums.....
First of all thanks for your posts, I found them very instructive.
i have a question that has been in my mind for very long. Does any other commercial airframe needs a software patch to pasd a certification requirement? Or to a certain extent certification was designed with software patches as remedies?
FrequentSLF is offline  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.