PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Australia, New Zealand & the Pacific (https://www.pprune.org/australia-new-zealand-pacific-90/)
-   -   Virgin Australia pushes back Boeing 737 MAX order (https://www.pprune.org/australia-new-zealand-pacific/621017-virgin-australia-pushes-back-boeing-737-max-order.html)

dr dre 30th Apr 2019 01:50

Virgin Australia pushes back Boeing 737 MAX order
 
For more than just the stated safety reasons??:

​​​​​​​Virgin Australia pushes back Boeing 737 MAX order

Dee Vee 30th Apr 2019 02:16

What else would it be?

And it's good news, it means I can continue to fly Virgin for a while without having to worry what aircraft is operating...

Boeing's CEO is blaming "pilot error" for the 2 crashes now, despite Boeing saying no additional training of pilots was required.... They have a serious credibility gap at this point in time....

SRM 30th Apr 2019 04:22


Originally Posted by Dee Vee (Post 10459328)
What else would it be?

And it's good news, it means I can continue to fly Virgin for a while without having to worry what aircraft is operating...

Boeing's CEO is blaming "pilot error" for the 2 crashes now, despite Boeing saying no additional training of pilots was required.... They have a serious credibility gap at this point in time....

Well I guess ultimately it was pilot error.

PoppaJo 30th Apr 2019 04:54

Capex headwind removed. Box tick.

Poor old Tiger. Stuck with this ballsup fleet plan until 2025. Hahahaha

ElZilcho 30th Apr 2019 05:11


Originally Posted by Dee Vee (Post 10459328)
What else would it be?

And it's good news, it means I can continue to fly Virgin for a while without having to worry what aircraft is operating...

Boeing's CEO is blaming "pilot error" for the 2 crashes now, despite Boeing saying no additional training of pilots was required.... They have a serious credibility gap at this point in time....

While their response was probably in poor taste and the MAX is looking more and more like a polished turd, ultimately, it was Pilot error.
Over the past few months I've seen a lot of people rant and rave about MCAS (including Pilots) who actually have very little understanding about the system.... or they understand the system entirely but fail to recognize what actually happens when it (or the sensors) fail.

The MCAS trims the Stabilizer, if it's doing this in error, you apply the memory items for the Stabilizer and disconnect it.

I agree, Boeing should have made Pilots/Airlines aware of the MCAS, why it's needed and how it functions, but as for training, none is required because if the MCAS is faulty, the existing memory items cover the potential faults, including unreliable Airspeed.

maggot 30th Apr 2019 06:42


Originally Posted by ElZilcho (Post 10459379)
While their response was probably in poor taste and the MAX is looking more and more like a polished turd, ultimately, it was Pilot error.
Over the past few months I've seen a lot of people rant and rave about MCAS (including Pilots) who actually have very little understanding about the system.... or they understand the system entirely but fail to recognize what actually happens when it (or the sensors) fail.

The MCAS trims the Stabilizer, if it's doing this in error, you apply the memory items for the Stabilizer and disconnect it.

I agree, Boeing should have made Pilots/Airlines aware of the MCAS, why it's needed and how it functions, but as for training, none is required because if the MCAS is faulty, the existing memory items cover the potential faults, including unreliable Airspeed.

Which "memory items for the stabiliser"? You mean for a runaway? (Which it wasn't). Meanwhile stick shaker, IAS disagree (toga thrust!) And, well. Pilot error I guess. Shame they couldn't just over power the stab with elevator as they say they could, eh

cessnapete 30th Apr 2019 07:44


Originally Posted by maggot (Post 10459407)
Which "memory items for the stabiliser"? You mean for a runaway? (Which it wasn't). Meanwhile stick shaker, IAS disagree (toga thrust!) And, well. Pilot error I guess. Shame they couldn't just over power the stab with elevator as they say they could, eh

with a propely trained competent crew they wouldn’t have had to overpower the stab.

As as soon as erroneous stick shaker recognised. Disengage A/P and A/T, fly the plane, (anathema to many airline SOPs) set pitch and power you should have as memory item for that stage of flight.( Unreliable ASI training on your Conversion Course) Co pilot handles the aircraft while Capt. Manages an expeditious return to the departure airfield, no need to fully retract the the flaps.
It really doesn’t help leaving TOGA power set throughout, and you do of course have a G/S display as a speed reference.










SRM 30th Apr 2019 07:45


Originally Posted by maggot (Post 10459407)
Which "memory items for the stabiliser"? You mean for a runaway? (Which it wasn't). Meanwhile stick shaker, IAS disagree (toga thrust!) And, well. Pilot error I guess. Shame they couldn't just over power the stab with elevator as they say they could, eh

Are you saying that the 737 cannot be controlled with the elevators if the stabiliser is the full AND position.

Does in the Sim at 250 kts.

No Idea Either 30th Apr 2019 07:56

It’s the TOGA thrust that got them maggot. Dynamic pressure goes up logarithmically and at 400 kts plus they just couldn’t pull the elevators to up and the stab to trim nose up, in fact the stab was still moving nose down, being ‘pushed’ by the air pressure. I don’t have an opinion in either direction, the warning noises, aerodynamic noise, multiple cautions, it would have been a very stressful situation, too stressful indeed. I know the memory items for unreliable airspeed but if you follow them and maintain level flight or a downwards trajectory then you are going to over speed quite significantly as shown here. The old saying.....’there but for the grace of god go I’ but I like to think I would have had the sense to identify the increasing airspeed. When we practice this in the sim (unreliable airspeed) we allow the aircraft to climb, as you do no doubt. And yes, I know, perhaps they thought they were stalling so persisted with the max thrust......but I know the outcome of max thrust and level flight at sea level/5000’ and so do you...........the MCAS, well we were all in the dark about it’s mysterious machinations but it was running for quite long periods of time over and over again. Watch your STS or autopilot trim next time, it would be lucky to run for a few seconds at a time followed by large periods of inactivity. Big picture stuff I suppose, and the other old saying as well.....’you get out of it what you put into it’. I believe that Ethiopian Airlines never disseminated the EAD to the crew that Boeing put out. We don’t fly the max so never got the EAD but I can tell you I’ve done a lot of research into this. I feel I have a reasonable appreciation of what happened and have thought about it a lot and what I would do in a similar situation, all with the benefit of hindsight of course, such a wonderful thing. So have you, I would assume and so have 99.9% of all Boeing pilots world wide.

hope I don’t come across as a condescending [email protected], I wasn’t there, never been in the situation, not sure how I would handle it but I would hope I could achieve a much better outcome.

ElZilcho 30th Apr 2019 08:45


Originally Posted by maggot (Post 10459407)
Which "memory items for the stabiliser"? You mean for a runaway? (Which it wasn't). Meanwhile stick shaker, IAS disagree (toga thrust!) And, well. Pilot error I guess. Shame they couldn't just over power the stab with elevator as they say they could, eh

Is it titled Runaway Stabilizer in the 737? Been a number of years so I honestly can't recall, but in the 777 it's simply titled "Stabilizer" in the QRH. Regardless, the condition statements refer to un-commanded movement of the stabilizer, or "Stabilizer movement without a signal to trim". The MCAS, when it activates, will trim nose down for about 9 seconds to alleviate a sensed high AoA. If a Pilot believes this trim to be in error, the memory items to disconnect the stabilizer would apply. The memory items also apply to a Failed Stabilizer, i.e. if the MCAS puts the Aircraft badly out of Trim and wont allow you to correct it.

As for Stick Shaker, IAS Disagree and TOGA thrust, again this is covered by the Memory items for Unreliable Airspeed. Flaps extended? 10 degrees and 85% N1 if I recall correctly. Easier said than done I realize, as they were battling both stick shaker and overspeed warnings, but those pitch and power settings would have kept them safe... or at the very least gotten them to reduce the thrust from TOGA.

I'm not trying to defend Boeing here, the 737 MAX quite possibly should of never been certified. BUT that's not to say there wasn't a component of Pilot error in the 2 accidents. Lion Air, for example, had an event the day before relating to MCAS but with the help of a jump seat pilot, disconnected the Stabilizer and returned safely.

gordonfvckingramsay 30th Apr 2019 09:05

So Boeing slip in a dodgy system which has the ability to drive two brand new aircraft into the ground and it’s pilot error??? I think the crumbs of incompetence will lead back to Boeing and the FAA.

Turbine Overheat 30th Apr 2019 10:49

Uncommanded trim
 
dont forget that in all B737 we have a wonderful system called Speed Trim. Which means it’s quite normal for the stab trim to move when we haven’t commanded it.

Couldn’t agree more with previous comments
there but for the grace of ...........

maggot 30th Apr 2019 10:58


Originally Posted by ElZilcho (Post 10459481)
Is it titled Runaway Stabilizer in the 737? Been a number of years so I honestly can't recall, but in the 777 it's simply titled "Stabilizer" in the QRH. Regardless, the condition statements refer to un-commanded movement of the stabilizer, or "Stabilizer movement without a signal to trim". The MCAS, when it activates, will trim nose down for about 9 seconds to alleviate a sensed high AoA. If a Pilot believes this trim to be in error, the memory items to disconnect the stabilizer would apply. The memory items also apply to a Failed Stabilizer, i.e. if the MCAS puts the Aircraft badly out of Trim and wont allow you to correct it.

As for Stick Shaker, IAS Disagree and TOGA thrust, again this is covered by the Memory items for Unreliable Airspeed. Flaps extended? 10 degrees and 85% N1 if I recall correctly. Easier said than done I realize, as they were battling both stick shaker and overspeed warnings, but those pitch and power settings would have kept them safe... or at the very least gotten them to reduce the thrust from TOGA.

I'm not trying to defend Boeing here, the 737 MAX quite possibly should of never been certified. BUT that's not to say there wasn't a component of Pilot error in the 2 accidents. Lion Air, for example, had an event the day before relating to MCAS but with the help of a jump seat pilot, disconnected the Stabilizer and returned safely.

Its been a while for me too but iirc it's 'runaway stabiliser'.
Just remember the stab running on/off oddly is normalised for 737 crew.

I tend to agree with above, it was TOGA that got them. I imagine it was a good idea when things went pear shaped down low - avoid a stall and get away from the ground. From there it unfortunately kept piling on and was left.


maggot 30th Apr 2019 11:00


Originally Posted by Turbine Overheat (Post 10459592)
dont forget that in all B737 we have a wonderful system called Speed Trim. Which means it’s quite normal for the stab trim to move when we haven’t commanded it.

Couldn’t agree more with previous comments
there but for the grace of ...........

indeed! Sage words.

maggot 30th Apr 2019 11:04


Originally Posted by SRM (Post 10459442)

Are you saying that the 737 cannot be controlled with the elevators if the stabiliser is the full AND position.

Does in the Sim at 250 kts.

Apparently not for the poor sods

Boeing CEO says so though. Hmmm

RickNRoll 30th Apr 2019 11:22


Originally Posted by SRM (Post 10459364)


Well I guess ultimately it was pilot error.


The pilots were the last ones to make an error.

Beer Baron 30th Apr 2019 13:29

I think it is grossly unfair to label this crash ‘pilot error’. The aircraft type was manufactured with a flawed system and the particular airframe suffered a failure on the day which the pilots were unable to overcome. That makes it an aircraft problem, not a pilot problem.

The pilots fought to to resist a plane that was determined to fly itself into the ground, ultimately they lost that fight.

Consider the Sioux City crash where they lost all 3 hydraulic systems. They valiantly battled to fly a crippled aircraft and saved many lives. But would you say the crash was ‘pilot error’ because a theoretical ‘competent crew’ could possibly have managed to land it safely and save all the passengers lives??

Cloud Cutter 30th Apr 2019 20:05

Last two posts sum it up.


This is a system safety failure rooted in poor design and engineering. A good design accounts for the human factors likely to be associated with conceivable failure modes. In this case, it doesn't take a rocket surgeon to realise that a highly stressed crew presented with multiple warnings (visual/aural/tactile/seat of pants) is not the right basket to be putting all of ones eggs in when it comes to recovering the situation. Add to that the likely confusion caused by two separate but equally obscure stabiliser trim-based stability augmentation systems and the reliance by the manufacturer on a non-normal checklist that was designed for a different type of failure entirely, and it becomes a tough ask for the average crew (let alone the lowest common denominator that the aircraft designer should have in mind).

T-Vasis 1st May 2019 05:46

The Boeing CEO stated that the 'pilots did not correctly follow the required procedures'. What did they not do correctly?

Red Jet 1st May 2019 09:22


Originally Posted by T-Vasis (Post 10460230)
The Boeing CEO stated that the 'pilots did not correctly follow the required procedures'. What did they not do correctly?

I think the inference was that the pilots of the Ethiopian flight allegedly RE-ENGAGED the stab-trim, after having initially turned the system off.


All times are GMT. The time now is 12:24.


Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.