Ethiopia crash

[John_Cillis 2,406]

27 minutes ago, IUBrian said:

I haven’t had much of substance to add to this topic but there are a couple of points I would be remiss if I didn’t make. One, immediately after the crash, as I think i mentioned near the beginning, I told my daughter I’ll hop over to Avsim and pretty quickly get a pretty fair assessment of what likely went wrong because there are a lot of really really smart people there. And I have not been disappointed - as a non-pilot the wealth of knowledge, even from differing opinions, has been incredible. 

The second point is that in this day and age it seems unfortunately rare that people can disagree without the disagreement devolving into personal attacks. I think it’s a credit to this forum generally and the moderators that we can express opinions and even strongly disagree without the conversation disintegrating into personal attacks. I feel with everyone, regardless of where we fall on this topic, if we met in person we’d all quaff a few beers together. 

 

 

Yes, very true.  Sadly the "safety" of forums allows some to stretch the envelope and use fighting words all the while knowing that in real life they'd get decked for using them, given the other person with moral high ground usually wins in physical fights but is defenseless when some just have to get the last written word in.  I will not say anything I would not be willing to defend myself if physically attacked by a flamer, but at the same time I have also stretched the limits at time and felt deserved to be decked were it not for the mods who put me on a few days time out to become myself again.

Forums also bring us aboard with other challenges, physical, work challenges and sometimes that causes us to vent a lot of steam or "shotgun" the forums which we realize, most of us, in retrospect is a mistake.  I see that in all forms of social media and Avsim at its basic is social media, but unlike Facebook and Twitter and so on, at least it is moderated and not a winner take all type of forum.

John

[Christopher Low 5,352]

Quote

and the most famous the series of unexplained Rudder Hard Over crashes due to a flaw in its rudder actuator which caused it to suddenly apply full rudder

I will always state that they should have grounded the entire 737 fleet over this one.

[John_Cillis 2,406]

16 minutes ago, Christopher Low said:

I will always state that they should have grounded the entire 737 fleet over this one.

I remember those crashes quite well, and I agree.  The 737's rudder was its Achilles heel, it must have been fixed though given the handful of crashes out of tens of thousands of flights.  I remember the US Airways crash but oddly I was never nervous because I always flew on such aircraft after such crashes knowing the pilots would have learned coping skills just in case. 

I still laugh that my most severe crash came in the form of my recent pedestrian accident just shy of three weeks ago.  I got to at least enjoy the high of pain killers, lol, but that high was bought at a high price.  I have been in several car crashes, bicycle crashes, oddly never a scooter crash, my friend had one in the late 70's and we would scooter to the city fair in 1978 I believe in Napa.  I have been in one airline ground crash and only slightly hurt my hip, happened in Jackson Hole as I have previously mentioned.

Crashes and mistakes happen, as Thomas Edison put it, it took many mistakes to make the lightbulb.  The airliner is still evolving.  We mourn those lost in crashes, but we must remember, death will meet us anyway, naturally or by accident.  It is how we prepare for it that is important, and how those who have gone before us somehow serve as angels making for a safer aviation and safer world, I swear the world is getting safer because I survived a most horrific impact and accident recently, and the good Samaritans whether right wingers or left wingers, I did not care about their creed, I simply accepted the help that saved my life on March 3rd, on the ground, I was not simming or flying then.

In other words I feel we learn from these accidents and those souls involved are in some type of afterlife helping us learn and create a better future for our world.

John

 

[Bobsk8 12,681]

15 hours ago, Jim Young said:

I agree with your premise but I read the FAA made it optional too.  Boeing, like Airbus, was just trying to save their customers some money.  I do not think both aircraft crashed because it was missing two optional features that saved them money.  The countries and airlines involved also had the option to buy the optional safety features.

the FAA is Boeings lap dog. 

[Bobsk8 12,681]

4 hours ago, John_Cillis said:

I remember those crashes quite well, and I agree.  The 737's rudder was its Achilles heel, it must have been fixed though given the handful of crashes out of tens of thousands of flights.  I remember the US Airways crash but oddly I was never nervous because I always flew on such aircraft after such crashes knowing the pilots would have learned coping skills just in case. 

I

John

 

The "coping skills" the pilots used in a hard over rudder was they said their prayers as they hit the ground. 

[IUBrian 151]

I haven’t seen anything that convinces me the Max is itself fatally flawed or inherently unsafe, just that its flight characteristics are different than the previous generation. And people saying they’ve stretched a 50 year old design too far, I haven’t seen compelling evidence that a clean sheet design would be significantly different than the existing plane - yes, maybe the wings would be shaped and placed differently, maybe the land gear would be longer, for example, but I don’t know that would necessarily make it a better plane, or even a safer plane, in particular because with the Max you incorporate a large number of known components with known reliability. A clean sheet design may be more fuel efficient, and would certainly (without software adjustments) fly differently than existing 737’s, but would it necessarily be a safer plane? If anything, the implementation of MCAS demonstrates the fallibility of humans in contemplating all of the consequences of their design decisions - think MCAS was a disaster - what happens when instead of one change you introduce tens of thousands of changes? Obviously we can look at the 777 and 787 as examples of safe aircraft (although not without their own issues), but simply saying “50 years is too old, need to start from scratch” is no guarantee of a better plane, nor does the fact that the Max is based upon a 50 year-old design mean it’s not capable of being a great plane.

 

That said, I do think Boeing has become complacent, and there needs to be significant management changes and more than a software fix to restore faith in the Max and the company. Like I said earlier, while I think there has been some discussion of Airbus versus Boeing, I don’t get the impression that the comments of those who are most critical of Boeing are coming from Airbus fans, it’s the opposite - it’s the fans of Boeing who are being critical.

[Adrian123 1,015]

4 minutes ago, IUBrian said:

I haven’t seen anything that convinces me the Max is itself fatally flawed or inherently unsafe

"Sweet dreams and flying machines in pieces on the ground"

[HighBypass 2,339]

Aircraft might be deemed inherently unsafe if one is not trained in their proper use. .. I would hazard a guess than anyone involved in aviation (professional or layman) knows not to walk close to the intake of a running jet engine... Yet there is NOTHING to actually prevent someone from doing just that.. Only "common sense" and self-preservation prevent sane people form getting killed.

Similarly once the flight envelope is exceeded in some way, then you may die, so do not do that.

As I (yes, a mere layman) understand things now:-

The MAX's LEAP engine nacelles caused an undesirable flight characteristic at high AOA, namely an increase in lift forward of the wing which increases pitch up, thus compounding a stall, or an entry into a stall,  and perhaps making a deep stall unrecoverable, especially at low altitudes. The fatal design flaw was IMHO not redesigning the nacelles to eliminate the lift component at high AOA. notwithstanding the accommodation of the weight and balance changes from re-positioning new engines on the old baby Boeing. After all, it has to be said that it appears the MAX does actually fly quite well.. under normal circumstances - it was quite a popular airliner...

Another flaw, but not a design flaw IMHO was not making it common knowledge to ALL MAX crews that MCAS was installed and how it operated.Was that Boeing's fault? Was that the airline's fault? I do not know and cannot say.

I wold hope that professional aircrew are trained in the flight characteristics of their aircraft, including training along the lines of "Do NOT let the plane do this or else it is game over" - a "dead man's curve" as it were on the flight envelope diagram.

Any aircraft has such an area of it's flight envelope. Example, if you get into a deep stall, you need X amount of altitude to recover. If you are closer than X to the ground then you are dead.

Of course steps are taken to try and prevent aircraft from ever getting to that part of their envelope, but it can and does happen: Aircrew presented with wrong data, computers presented with wrong data, both doing the job as they are trained and programmed to do respectively.Yet because the data was wrong it leads to a crash. Given enough time, the aircrew may save the day by thinking outside of the box, but sometimes there is not enough time... and the computer never thinks outside its box.

[KevinAu 441]

3 hours ago, HighBypass said:

As I (yes, a mere layman) understand things now:-

The MAX's LEAP engine nacelles caused an undesirable flight characteristic at high AOA, namely an increase in lift forward of the wing which increases pitch up, thus compounding a stall, or an entry into a stall,  and perhaps making a deep stall unrecoverable, especially at low altitudes. The fatal design flaw was IMHO not redesigning the nacelles to eliminate the lift component at high AOA. notwithstanding the accommodation of the weight and balance changes from re-positioning new engines on the old baby Boeing. After all, it has to be said that it appears the MAX does actually fly quite well.. under normal circumstances - it was quite a popular airliner...

Actually, that is completely speculative on the part of a user on pprune. The only reasons so far in industry literature (aw&st) and airline bulletins (swa) that I have seen cite difficulty in stall recovery due to engine position and thrust. Not a new longitudinal instability issue as posited on pprune by fceng84. As such, difficulty in maintaining attitude control during stall recovery and even go arounds, is inherent and anticipated in this class of aircraft. This was an issue on the NGs and the greater thrust of the max engines exacerbated it to the extend that some sort of mitigation, such as a stick pusher, had to be introduced. Per the Southwest Airlines’ recent bulletin to pilots on the upcoming changes to  mcas, in lieu of installing the stick pusher, which would have required sim training, mcas was implemented to run in the background, in order to make sim training unnecessary.

Edited March 23, 2019 by KevinAu

[threexgreen 3,139]

21 hours ago, DellyPilot said:

Design flaw 1 - Misleading warnings + 80K extra to get the right warning
...

Design flaw 2 - MCAS works off only 1 AoA vane and is active even when 2 AoA inputs disagree
...

Design flaw 3 - Applying 2.5 degrees pitch forward every 10 seconds
...

Jim and others who are saying wait for the report and airbus are just as dangerous, sorry guys but what in the...? If you can't see this is a design flaw then what is?

This is partly why patching a 50 year old design with a complex automation system AND then not training crew about it is in my view is criminal. There will be court cases.

But even with the current implementation its crazy not to have input validation/correlation checks for such a key system, how the FAA agreed to no ECAM Messages is incredible.. there should be audible warnings too MCAS ACTIVE! MCAS TRIM!

Finally to address your last point.. orders were made long before the design flaws were realised.

I agree with you on the flaws you list here. However, these flaws are MCAS specific design flaws, not flaws in the overall design of the aircraft, as you said initially in your post that I replied to. Implement the software update to make MCAS behave as it should have from the start and you have a perfectly safe, modern and efficient aircraft that, given it's orders, will play a crucial role in narrowbody service in decades to come. This is my point, apart from MCAS where Boeing obviously have failed to develop an adequate design from the get-go there's nothing that would suggest this aircraft is flawed as an overall design. Still, people seem to commonly take the MCAS design issue as evidence for just this.

To weigh in on some of the more detailed points you make:
- New checklist for MCAS emergencies: I doubt anyone, that includes Boeing, was aware before the Lion Air crash how horribly wrong an erroneous MCAS activation could go, therefore, no new checklist for this emergency was developed (which should be done now)
- Small correction: On stall recovery, you only carefully add thrust once the aircraft is in a nose down attitude to build speed, not immediately as the increase of thrust pitches the nose up which makes things even worse
- The amount of times that MCAS kicked in and was responded to by the pilots on the Lion Air flight was over 21 times

As for the orders, an overall design flaw of the aircraft as a whole would certainly be obvious and have made certification close to impossible (yes, the certification process seems to have been fishy) and carriers such as United Airlines or Southwest, among others, would not make this aircraft a large part of their narrowbody plans. Hence, 5000+ orders (or slightly less than that, given what Garuda are up to) and the pace at which the order book was filled do not speak for a fundamentally flawed aircraft design.

On a side note, I'm not sure if Garuda are making much of a right decision by scrapping their order of 50. Passenger trust has been lost, obviously. However, I'm fairly certain the general public will forget about this sooner rather than later. Once the software fix is mandated and installed, the fleet will go back into service and be perfectly safe and while I, personally, wouldn't at this time (if I could), I would happily board a MAX after the grounding is over. Plus, changing your order of which you already received an airframe will only put you at the end of a backlog of a load of orders.

 

 

[HighBypass 2,339]

10 minutes ago, KevinAu said:

... mcas was implemented to run in the background, in order to make sim training unnecessary...

Does anyone else find this a slightly disturbing idea? No sim training is necessary - you don't need to know about a system which IF it goes wrong might confuse you just long enough to crash before you can save the plane. The word "insidious" comes to mind, however I feel that would be too strong - I believe MCAS in and of itself is not evil or harmful, nor was it ever meant to be. It will help alleviate the onset of a (really) bad situation IF it is operating on good data..... IF.

Kevin: I did say in a previous post that I found the pprune thread made for interesting reading. I thought it had increased my understanding of the situation, perhaps it hasn't.

[threexgreen 3,139]

4 minutes ago, HighBypass said:

Does anyone else find this a slightly disturbing idea? No sim training is necessary - you don't need to know about a system which IF it goes wrong might confuse you just long enough to crash before you can save the plane. The word "insidious" comes to mind, however I feel that would be too strong - I believe MCAS in and of itself is not evil or harmful, nor was it ever meant to be. It will help alleviate the onset of a (really) bad situation IF it is operating on good data..... IF.

I think there is no one who would try and argue with you on this - the fact that Boeing didn't think it was necessary to tell pilots about MCAS and the changed behaviour of the aircraft close to a stall is negligence and a threat to safety. It's not exactly much of an effort to bring MCAS to the pilot's attention through the flight manual.

I don't see an issue with the fact that MCAS has been implemented to help with the stall recovery. The design of the software is the issue which is rightfully getting a much needed overhaul. That, however, comes too late for the souls lost.

Keep in mind that the reason why MCAS exists is not only to counteract the increased pitch up close to stalls. Without MCAS, the MAX would exhibit flight characteristics in said situation that don't conform with the certification requirements. No MCAS, no MAX, regardless of whether there is pilot training or not.

[KevinAu 441]

50 minutes ago, HighBypass said:

Does anyone else find this a slightly disturbing idea? No sim training is necessary - you don't need to know about a system which IF it goes wrong might confuse you just long enough to crash before you can save the plane. The word "insidious" comes to mind, however I feel that would be too strong - I believe MCAS in and of itself is not evil or harmful, nor was it ever meant to be. It will help alleviate the onset of a (really) bad situation IF it is operating on good data..... IF.

Kevin: I did say in a previous post that I found the pprune thread made for interesting reading. I thought it had increased my understanding of the situation, perhaps it hasn't.

It is an interesting thread over there, but I wouldn’t take it as The Reason. I don’t doubt that the nacelle body provides some lift, but my non-engineer, just a pilot bet is that of the XXlbs of arm force I’m using to push over from a go around or stall recovery, XXlbs is fighting where the trim is, XXlbs is fighting the max thrust, and xlbs is fighting the nacelle body lift.

That you are actually pushing forward to keep the plane from stalling is not new or unique to the max. That part is clear to me from the stall maneuvers we did in the E190 during recurrent this year.

Not requiring sim training is not inherently evil as this plane was meant from the beginningto be similar to the previous versions. But not having a proper explanation for an antistall function and not having procedures people work out a qrh procedure for it’s malfunction is concerning. That whole bit about just going back to the trim runaway procedure was negligent at best, and at worse, dictated by lawyers in an attempt to mitigate liability from the lion air crash.

Edited March 23, 2019 by KevinAu

[IUBrian 151]

2 hours ago, threegreen said:

 

On a side note, I'm not sure if Garuda are making much of a right decision by scrapping their order of 50. Passenger trust has been lost, obviously. However, I'm fairly certain the general public will forget about this sooner rather than later. Once the software fix is mandated and installed, the fleet will go back into service and be perfectly safe and while I, personally, wouldn't at this time (if I could), I would happily board a MAX after the grounding is over. Plus, changing your order of which you already received an airframe will only put you at the end of a backlog of a load of orders.

 

 

This may have nothing to do with the Max, per se. A story I read said there are some smaller airlines with financial issues that may be looking for an excuse to get out their orders. This provides them a potential excuse that avoids the financial implications of being sued for breach of contract.    

[IUBrian 151]

Another interesting article, not so much on the technical side, but the business side, specifically the arrogance of Boeing management. 

https://www.nytimes.com/2019/03/23/business/boeing-737-max-crash.html