737 problem explained

Sigh.

Just because all crows are black birds, you can't infer that all black birds are crows.

Or at least you can't /correctly/ infer that.

Right. I didn't bring up the distinction between direct and indirect democracy.

If the government acts as though the law is the highest authority and not the people, then it certainly does protect against bad decisions made by the people. But then the progressive movement came along.

I was refering to the bad decisions they make when they vote. What else could a reference to "democracy" mean since we don't have direct democracy. Land owners made better choices (Jefferson, Adams, Madison) than non-land owners (Jackson, Polk) but freedom to decide is why all people can decide, not because they make good decisions. The free market, as I said, exists for the same reason, not because they pick the best products.

Then she sighed. Then they both sighed, side by side.

I didn't suggest anything with such certainty. You did in the case of conservative papers.

You don't actually say anything that can be argued. So I won't bother to argue the point.

--

  Rick C. 

  +-- Get 1,000 miles of free Supercharging 
  +-- Tesla referral code - https://ts.la/richard11209

But the coders are the very last stage of the process of converting requirements into a real implementation. This *wasn't* a coding error - the control algorithms for MCAS were fundamentally flawed and apparently no-one picked up on it or more likely if they did they were ignored.

Boeing even deliberately erased all mention of MCAS from the 737-Max flight manual - they missed the entry in "Glossary of terms" though.

FAA "oversight" has very serious questions to answer and can no longer be considered a competent authority to certify US planes as airworthy.

Boeing was marking its own homework and putting profit ahead of safety.

--
Regards, 
Martin Brown

+1

And the coders are not aero engineers, it's not clear they knew what impact MCAS would have. One issue some programmer might have raised was that there was no check for a normal reading of the AOA sensors while the airplane was still on the ground. In the Ethiopian crash it was reading something totally abnormal, like 35 deg while the plane was still on the ground.

And Boeing increased the amount that MCAS could move the trim from what the FAA was initially told and then did not tell the FAA.

One thing no one has talked about and which I think is another huge Boeing screw up, is the directive they put out after the first crash, what they told pilots to do, did not work. They told the pilots to follow the runaway trim procedure, which is to shut off electric trim and trim manually. The pilots in the next crash followed that, it did not work. And Boeing should have known it may not work. Why? Boeing knew back from the early days of 737 that if the trim runs way off and the plane is going fast enough, it can be impossible to move the trim wheels by hand. They had a procedure in the documentation that warned pilots of that and outlined a procedure of putting the plane into a dive to relieve the pressure, then adjusting the trim. Over the decades, that was removed.

But when this MCAS problem came up, one would think someone at Boeing, test pilots for example, would have said that the runaway trim procedure may not work. What would have worked:

1 - Use the trim buttons to get trim back to close to normal position. 2 - Once near normal, immediately turn of the trim cut off switches and trim manually. (they would have had I think 5 seconds before MCAS would again do it's trim down)

This seems like a very obvious procedure for another reason. Boeing knew that MCAS is disabled with flaps deployed and that the trouble started with the Lion Air flights as soon as they were retracted while climbing out. So, pilots don't have very much time to identify the problem and take corrective action. It takes more time to turn the trim wheels by hand than using the above procedure. They did point out that MCAS is disabled with flaps, but using flaps to stop it was not in the procedure and the Ethiopian pilots just followed the procedure.

The flaps thing has another angle too. IDK about you, but anything I'm working with, if I change something and suddenly everything goes sideways, one of my first reactions is to undo what I just did. All three incidents occurred just as the flaps were taken off. If any of the pilots had tried reversing that, deploying the flaps again, the crashes all would have been avoided.

Martin Brown wrote

This is a misrepresentation, because the bigger picture is more complex.

Boeing had no interest in producing an unsafe aeroplane. The problem here is a combination of several things

- the airlines wanting a common Type Rating (I am a pilot too, btw) and applying a lot of pressure to get it, and this implied not documenting the MCAS differences

- Boeing cocking up the software (but Airbus have done similar things, which is why they are not gloating too much)

- the two airlines that crashed the MAX having poorly trained pilots (go to any commercial pilot school and watch the bulk of the clientele, these days ;))

- the two crews that crashed doing silly stuff on departure which activated MCAS

- poor maintenance (departing with defective AoA sensors)

You need all these holes in the cheese to line up.

Peter wrote in news:qu5k60$pdo$ snipped-for-privacy@dont-email.me:

Finally, someone with a reasoned perspective.

Some of the crap I have seen must have been posted by Trumpanzee idiots.

I have never seen anything nearly this bad, from any other aircraft manufacturer.

That's an undeserved smear. The young co-pilot with just 200 hours correctly identified the runaway trim in the Ethiopian crash. He followed the Boeing procedure, put out after the first crash. His last words were that he could not move the trim. Boeing's procedure was badly flawed, just like the plane. And this is AFTER the first crash, when Boeing had plenty of time for input from test pilots, etc, to come up with the right procedure.

That's a big lie. The takeoff procedure was perfectly normal. The plane, not so much...

It looks like maintenance was an issue in the first crash. I have heard nothing about it being an issue in the second crash.

Whoey Louie wrote in news: snipped-for-privacy@googlegroups.com:

When you make your retarded responses to others, try to respond to THEIR posts, not after mine as if to be responding to me, because you were not.

I just responded to your cut and paste post. I wasn't going to try to trace back from where all you assembled it.

Whoey Louie wrote in news: snipped-for-privacy@googlegroups.com:

IOW, you're a Usenet total retard.

I 'assembled' nothing.

They used to have a very good reputation but that is long gone now.

I see no reason to trust the FAA at all. They have clearly demonstrated from the outset that they were in Boeing's pocket and *VERY* slow to react even when they basically knew that they were flying coffin ships.

It is slightly surprising that FAA didn't cave in to Boeing's recent attempt at blackmail which led to their CEO having to go.

FAA may be a toothless watchdog but at least they have finally woken up!

Sacrificing the CEO might just focus minds.

--
Regards, 
Martin Brown

Oh, I think the minds are focused by other things ( loss of lives, decertification of aircraft, costly inventory buildup in large parking lots, stock value falling).

Boeing's CEO just got replaced, but that's a very minor bit of the drama. One could argue for replacing the FAA administrator, but there was none at the time of the crashes, the administration hadn't made that appointment.

Here is an interesting item:

"Trying to land on some runways causes the Boeing 737's control screens to go black"

Now that's quite stunning and something you'd never expect. I wonder what other unexpected software interactions are in planes that no one has found yet?

aunch/

rements

hat

the

Hmmm- the French lost an Airbus with three angle of attack sensors. One was good, two were bad due to icing, and the voting scheme threw out the good reading and went with the two bad ones. Looks like you latched onto yet ano ther flawed hypothesis. You can read about it here:

-crash/95893.article

Deliberately obfuscating a system that has the potential to dive the plane into the ground in the event of a relatively common fault.

Boeing internal emails released to the enquiry and leaked today suggest that there were knowledgable voices inside Boeing very unhappy with the way the 737-Max was being "engineered". The quote making the headlines is "Designed by clowns who in turn are supervised by monkeys".

They were flying normally until they retracted the flaps after takeoff and MCAS cut in with its very determined effort to crash the plane. The second lot even tried Boeing's approved "fix" but already starting at high altitude on takeoff and surrounded by even higher mountains they didn't have enough physical strength, time or space to make it work.

One thing that did surprise me as a non-pilot was why the SOP for recovering from an MCAS MFU was not to extend flaps again to slow the plane and take the MCAS unit out of the loop. Minor mechanical damage, fuel economy and noise are unimportant when the alternative is crashing.

Boeing seems to have too many holes in its cheeses though. The latest

737 MFU is don't land on runways at exactly 270 in certain airports!

They seem to be unusually accident prone and the FAA asleep on the job.

--
Regards, 
Martin Brown

I brought this up earlier too. And this was after the first crash, when Boeing, it's test pilots, etc. had plenty of time to think about what would work quickly and effectively. Extending flaps to the first position would have worked. Instead they opted for using the runaway trim procedure. And with that, they have been lucky, because any runaway trim caused by anything, eg a stuck switch, could apparently produce the same result in any 737. Which is that it may be impossible for the pilots to move the trim wheels by hand if the plane is going too fast, diving too steeply, etc.

The other thing that would have worked, that should have been offered as an alternative would be to first use the trim buttons to get the trim back to near normal and then immediately turn off the electric trim and then trim the rest of the way by hand. You would think pilots that really understand the system and the issue after Boeing alerted them would have thought of this too, but the Ethiopian pilots did not. Also IDK about you, but with any system I'm dealing with, if I change something and then suddenly everything starts to go wrong, me first reaction is to undo what I just did. If these crash pilots had just done that, ie re-extend flaps, like you say, MCAS would have been disabled.

-launch/

uirements

that

n the

as good, two were bad due to icing, and the voting scheme threw out the goo d reading and went with the two bad ones. Looks like you latched onto yet a nother flawed hypothesis. You can read about it here:

an-crash/95893.article

I think you're referring to the A340 that went down off Brazil? If so, most of that is wrong. It was not AOA related, it was the pitot tubes that measure air speed that iced up. And the autopilot didn't decide to trust any of the sensors. As it lost input, it backed off to alternate flight rules to allow the autopilot to continue to fly the plane. When it lost the last speed input it dumped the plane back into the hands of the pilots. It was during turbulence in a thunderstorms, at night and the pilots screwed up. The correct procedure was to set the power at like 70%, maintain a certain nose up pitch and the plane would fly just fine. One very good question there is why the autopilot didn't default to simple method as the final step, instead of dumping it to the pi lots. This was another crash that shows how even trained pilots for a major airline can screw up. I think one of the pilots was continuing to pull back on the controls as the plane was stalled and heading to the sea.