Boeing's safety analysis of 737 MAX flight control had crucial flaws - Seattle Times

[uppityperson]

Source: Reuters via Yahoo via Seattle Times

Reuters) - Boeing Co's safety analysis of a new flight control system on 737 MAX jets had several crucial flaws, the Seattle Times reported on Sunday.

Boeing's safety analysis of the flight control system called MCAS (Maneuvering Characteristics Augmentation System) understated the power of this system, the Seattle Times said, citing current and former engineers at the U.S. Federal Aviation Administration (FAA).

The FAA also did not delve into any detailed inquiries and followed a standard certification process on the MAX, the Seattle Times reported citing an FAA spokesman.

The report also said both Boeing and the FAA were informed of the specifics of this story and were asked for responses 11 days ago, before the crash of an Ethiopian Airlines 737 MAX last Sunday, killing all 157 people on board. The same model flown by Lion Air crashed off the coast of Indonesia in October, killing all 189 on board

Read more: https://www.yahoo.com/news/boeings-safety-analysis-737-max-162516297.html

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https://www.seattletimes.com/business/boeing-aerospace/failed-certification-faa-missed-safety-issues-in-the-737-max-system-implicated-in-the-lion-air-crash/

Flawed analysis, failed oversight: How Boeing, FAA certified the suspect 737 MAX flight control system

As Boeing hustled in 2015 to catch up to Airbus and certify its new 737 MAX, Federal Aviation Administration (FAA) managers pushed the agency’s safety engineers to delegate safety assessments to Boeing itself, and to speedily approve the resulting analysis.

But the original safety analysis that Boeing delivered to the FAA for a new flight control system on the MAX — a report used to certify the plane as safe to fly — had several crucial flaws.
(Clip)

The safety analysis:

.Understated the power of the new flight control system, which was designed to swivel the horizontal tail to push the nose of the plane down to avert a stall. When the planes later entered service, MCAS was capable of moving the tail more than four times farther than was stated in the initial safety analysis document.
.Failed to account for how the system could reset itself each time a pilot responded, thereby missing the potential impact of the system repeatedly pushing the airplane’s nose downward.
.Assessed a failure of the system as one level below “catastrophic.” But even that “hazardous” danger level should have precluded activation of the system based on input from a single sensor — and yet that’s how it was designed....(more @ link)

Incredible.

[NurseJackie]

1. uh-oh.

Little wonder that people are selling the Boeing stock.

[PSPS]

2. It was George W Bush's administration that brought us this "self-certification" nonsense

[Canoe52]

3. The fox guarding the henhouse effect.

[DoctorJoJo]

4. Hey, What's a Couple of Stray Ones and Zeros Among Friends?

[sandensea]

5. As in:

"Shit! There's a problem!"

"Would it be expensive to fix?"

"Yessir, we'd have to start all over."

"Cover it up then."

[OMGWTF]

15. Same as the Ford Pinto that exploded when rear-ended. Cheaper to kill people than fix it.

May they who have done this never know a good night's rest again.

[sandensea]

20. +1

And the best part is, our Republican friends and neighbors all applaud them - despite being just as likely to be potential victims as the rest of us.

Just because "it irritates them lib'ruls."

Never ceases to amaze me.

[burrowowl]

43. Since they changed engine and wing location

it is a whole new plane, they really 'fucked up'!

[sandensea]

47. And what's worse tried to hide it, safety be damned.

Duplicity's all the rage these days.

[MyOwnPeace]

6. So......

We're counting on corporate executives and former lobbyists to fix this for us now?

Oh, wait, we have an "Interim" Director responsible for the oversight of it all.

WHEW!!!!!!!

I feel better now.

[KT2000]

7. whatever happened to Boeing's

triple backup? Is that a thing of the past?

[jimmil]

8. Many years ago...

In another lifetime I did testing of software. Most of the time the software worked just as advertised. Of course, software was written to requirements, testing was done to requirements, and everything in software land was peachy. I never believed in that. I always said that making a program work was easy, but making it work when everything else was going wrong was vastly different. Every conditional statement was not tested. Every range was not tested. Every result was not tested. 300+ people are dead because Boeing had overstated schedules, signed off on untested software, and were more concerned with quarterly profits than human lives.

[icymist]

9. Boeing is so screwd on this one.

Going against a long Boeing tradition of giving the pilot complete control of the aircraft, the MAX’s new MCAS automatic flight control system was designed to act in the background, without pilot input.

It was needed because the MAX’s much larger engines had to be placed farther forward on the wing, changing the airframe’s aerodynamic lift.

The pilots on their rumor network (PPRuNu) have been citing that the placement of the bigger engines on a design that more than 50 years old to be the problem. Instead of creating a new design to work with the bigger engines, Boeing tried to force the older design to compensate with computer software.

This would be like putting a 429 big block engine in a Pinto and wondering why it always winds up on its side when the throttle is wide open. Then creating a computer program to force the car to be able to drive with way too large engine.

https://www.seattletimes.com/business/boeing-aerospace/failed-certification-faa-missed-safety-issues-in-the-737-max-system-implicated-in-the-lion-air-crash/

https://www.pprune.org/

[oldsoftie]

10. I've said from the start a human should ALWAYS be able to over ride a computer.

Ever since it was first talked about years ago.
Computers can be super smart & super fast and still not have any common sense.

[icymist]

11. Exactly! Look at this little gem from the Times article:

Peter Lemme, a former Boeing flight controls engineer who is now an avionics and satellite-communications consultant, said that because MCAS reset each time it was used, “it effectively has unlimited authority.”

In other words, every time this computer program was used (by the computer) it would reset itself and the pilots either didn't know or were not allowed to override it!

[cstanleytech]

12. I am not sure if I would agree as even humans make mistakes so

rather than letting the decision be solely up to one human alone it should be designed so that both the pilot and the co pilot have to concur and act together to override it much like how it used to take 2 people to agree to launch nuclear missiles.

[icymist]

18. That would be great, but unfortunately there was no such way to override this system.

eom

[cstanleytech]

24. Yes, I did read it. I am simply pointing out the potential pitfalls of letting a single person

make such a decision that can impact a large number of lives as humans are not anymore infallible than machines.

[oldsoftie]

26. Thats fine too. Although what if one is incapacitated?

I mean, the computer could fix a "mistake", but if over ridden more than once maybe it would cease to try to take control? I'm NOT a pilot, so my opinion is just a laymans thoughts.

[paleotn]

17. Computers are super fast...

That is often misconstrued for smart. But most simply follow their programming, errors and all. They learn, but only in rudimentary ways and sometimes in a manor in which any 6 year old human would stops and say bullshit. As you can imagine, I don't subscribe to the singularity nonsense. Certainly not in my lifetime. And I'm not sure which is more dangerous...a computer that goes blindly along thinking only in the manner in which it was programmed or a human who's distracted by too much random thinking.

[icymist]

19. Unless you're trying to say that Boeing installed AI into the aircraft, computers don't 'think'.

That would be like a math equation thinking.

[paleotn]

23. My statements were more general...

A response to computers being "super smart." In Boeing's case it initially appears to just a bad system. An ill conceived fix for a bad design.

[icymist]

25. Okay, I just needed some clarity.

And it isn't a bad design, just an old design. I mean that these planes were quite safe from the 60's all the way up until 2015, when Boeing decided to attach those really large engines.

[oldsoftie]

27. I agree. Its time to shelve the 50 yr old body design. Like they've done with NEWER designs.

I think a few of their aircraft that came out in the 80s have even been replaced with new designs.
Everything's great until some start falling out of the sky

[burrowowl]

44. You are right

damn thing needed to be redesigned, Boeing really screwed up.

[lagomorph777]

46. The Pinto analogy is apt.

The Pinto's engine was WAY to big for its transmission. As a result, the transmission was notoriously failure-prone.

[Chemisse]

13. It's fortunate the black boxes were sent to France

Although I doubt a Boeing-directed coverup would work, considering all the other evidence that has accumulated about the cause of the crash.

At what point do airlines lose confidence in American manufacturers which don't seem to be subject to adequate safety oversight?

[cstanleytech]

14. Yup, its simply further proof that you cannot rely on any industry to police itself and

yet the Repugnants keep saying that we need less government oversight.

[OMGWTF]

16. Rethuglicans want less oversight like crooks want fewer police.

[oldsoftie]

28. I've said that to some of my friends who bitch about ANY regs.

I've asked them, do you REALLY trust the airlines to do maintenance on schedule if no one is watching?
Do you REALLY trust the meat packer to make sure the meat is what its supposed to be without anyone watching? That the equipment is cleaned according to schedule?
The hospital is following proper procedures without someone watching?
Etc Etc

[Recursion]

21. The government will nationalize Boeing before it gets sued into oblivion

Man, they are screwed

[DFW]

22. Thalidomide avionics.

With predictable results.

[Doodley]

29. Devastating. If true, the FAA needs to be investigated and Boeing needs to go out of business.

[CaptainTruth]

30. As an engineer, this is absolutely unacceptable.

Every flaw in the MCAS system that lead to the crashes was a conscious decision by Boeing, none of them were accidents.

I see massive lawsuits, & frankly, Boeing deserves it.

To me this ranks with Morton-Thiokol managers overruling engineers when they said the space shuttle Challenger shouldn't launch because it was too cold for the booster O-rings to seal properly.

[The_jackalope]

31. +1 - As a retired software engineer I agree wholeheartedly

My experience with software design and testing has left me uncomfortable with fly-by-wire systems ever since they were introduced. Throw in a little management-influenced groupthink and this is the unfortunate result.

[Sgent]

39. This isn't (really) a fly by wire issue though

The 737 is not a FBW airplane and Boeing was trying to avoid designating as such -- which would require Boeing to bring it up to modern standards instead of being grandfathered.

They instead created the MCAS, which they designated as akin to a stick shaker, and created a system that can independently bring the plane down.

[Sunlei]

33. It took a few minutes for the plane to hit the ground & not a word from the pilots?

software shouldn't even allow a plane or a ship to path into a crash. Our military has also had recent software trouble where ships crashed.

[oldsoftie]

34. And whats gonna happen if & when we have a solar incident or EMP event or similar?

Everything has to be able to be manually controlled.

[Sunlei]

36. was just surprised, why didn't they say anything?

[uppityperson]

37. I expect they will eventually release the audio in some form. I'm not sure why you think the pilots

were silent.

[whopis01]

41. What makes you think the pilots didn't say anything?

[ga_girl]

42. If in trouble

Aviate - control the airplane
Navigate - Go someplace safe(r)
Communicate - Tell someone what's going on

[progree]

35. I'm so goddam sick of this shit. I'm so fucking glad I'm retired (former engineer, another industry)

As Boeing hustled in 2015 to catch up to Airbus and certify its new 737 MAX, Federal Aviation Administration (FAA) managers pushed the agency’s safety engineers to delegate safety assessments to Boeing itself, and to speedily approve the resulting analysis.

[Takket]

38. sounds like they did a hazard analysis and ignored their own results

people are going to prison for manslaughter for this, eventually.

THIS is what happens when you get rid of regulations (or don't have them to begin with). Putting the wolf in charge of the hen house.

[PuppyBismark]

40. Had Congress, i.e. the GOP given the FAA enough money to do certifications...

The major reason that air plane manufactures do most of the certification and inspection processes is that the FAA budget is no where near it needs to be. And you can all bet that their budget will never be that big with the GOP having anything to say. In some ways, this is not so bad as the manufacturers have much more technical expertise than an FAA employee and pay better.

That being said, it appears that Boeing made a major mistake in characterizing the MCAS and it should never had only one angle of attack input, rather than a two input redundant system. Thus when the single angle of attack sensor was incorrect, the MCAS system tries to fix the problem that does not exist.

However, the problem was identified after the first crash and a procedure published both by Boeing and the FAA, as well as in the aviation press. When a MAX 8 starts have runaway pitch down, the pilots should turn off the motors for trim. These switches are located just below and to the right of the throttles. It would appear that this procedure did not get communicated and trained with the Ethiopian air crew. If I know this just being an aviation enthusiast, one would assume the two Ethiopian crew members should have known what to do.

A couple of other items to note. Southwest Air MAX 8 aircraft have dual angle of attach sensors and thus they recognized the problem and I would assume their MAX 8 planes would be safe to fly. Also, it is reported that Boeing has a fix that was delayed 5 weeks by the Trump government shutdown and thus Trump killed the people on the Ethiopian for his wall. It is reported the fix takes two hours to install as it is only a software fix. That fix should have been installed before the second crash.

[burrowowl]

45. Unfortunately we don't send top management to prison

where they should be.