Boeing 737 Max design error

Sylvia Else wrote in news: snipped-for-privacy@mid.individual.net:

Right, which means they still used the term, but moving an entire control surface is not "trim". It is wresting full control of a critical surface. One does not use "trim" to avert an impending stall. They use the 'electric trim system', becuase it is a part of that, but the term itself is a misnomer here. Trim is a term used to describe SMALL elements which were incorporated into planes so that a flight can be adjusted out to reduce pilot stress and nowadays to increase fuel economy. So now it is being used to describe any adjustment surfaces so that a standard "released stick" does not cause a sudden change in flight characteristics. IOW, the pilot no longer had to hold the stick at a certain position to maintain 'level flight'. he could adjust it out such that a 'released stick' does not cause a sudden change to the current flight circumstances.

And we are not talking about 'different aircraft' on my suggestion, I was referring specifically to this plane.

Sylvia Else wrote in news:gjdgu4Fpd55U1 @mid.individual.net:

The entire tailplane IS the elevator. Standard aircraft element nomenclature.

snipped-for-privacy@optonline.net wrote in news: snipped-for-privacy@googlegroups.com:

You are a goddamned idiot.

Flaps on large passenger planes, for your information, ARE actuated by hydraulic cylinders.

That is whay airplanes have hydraulic systems in them.

You need to grow the f*ck up, you childish little piece of shit.

tirsdag den 7. maj 2019 kl. 23.50.53 UTC+2 skrev snipped-for-privacy@decadence.org:

snipped-for-privacy@optonline.net wrote in news: snipped-for-privacy@googlegroups.com:

Obviously a pilot decided change cannot be implemented fast enough, or we would not be discussing crashes, we would be discussing a huge error found by a complaining pilot.

snipped-for-privacy@optonline.net wrote in news: snipped-for-privacy@googlegroups.com:

You are an idiot. There are many.

The B1 bomber, is one major one.

Military planes have been fly by wire since the F-16, but not passenger planes until more recently.

They were having crashes in their first tests back in '81.

That is mil planes.

How many passenger planes do you think are that way?

"you have not seen" a whole lot of things TraderTard4.

snipped-for-privacy@optonline.net wrote in news:13ccb619-d461-4462-b15e- snipped-for-privacy@googlegroups.com:

I know more about it than you do.

Hell, I learned more about it on my flight simulator than you have in all your "I wanna be an expert" attempts at getting up to speed on it. Yet another failure for you.

onsdag den 8. maj 2019 kl. 00.13.16 UTC+2 skrev snipped-for-privacy@decadence.org:

screws actuated by hydraulic motors,

snipped-for-privacy@optonline.net wrote in news:e6e39425-fab4-4bfa-a06e- snipped-for-privacy@googlegroups.com:

Go away, little boy. You are too stupid to participate in this discussion.

Explosive bolts and the like are not complicated, but for you a salt shaker is complicated.

You are 100% clueless about avionic systems.

I don't know what's wrong with you.

Note the hinged section. That's the elevator.

Sylvia.

The jackscrew controls the angle of the tailplane. If it were 'freed' the tailplane would be left flapping in the breeze.

That happened once, to an MD-83, and the result wasn't pretty.

Sylvia.

Boeing 737 Max Fun Edition:

!!! >=D

Bye, Skyfun.

Clearly, it's not a happy place to be.

But from a design perspective, the question is going to be how to balance the needs of the pilots in a 'normal' runaway trim scenario against the needs of pilots who've let things get out of hand.

Increasing the turn ratio to make it easier to turn the wheels in the extreme out of trim case makes life harder for those pilots who have to manually operate the trim to fly the aircraft to a suitable landing place after they've dealt with a runaway trim properly.

Boeing obviously don't want to write in the handbook - "You and your passengers are doomed - you should have got more training", so they offer up something, but it stills comes down to "How on Earth did you get here in the first place?"

Sylvia.

Unless we're just talking about gross pilot incompetence.

Sylvia.

Correct, I had a braino while editing.

Other than them apparently being able to self-certify this component, and by some accounts having ultimately allowed it several times more trim authority than originally designed for and documented, I know nothing about it more than I have read from public sources. Just a big systems engineering failure all round.

The 737 can be flown manually; literally with only the forces generated by the pilot. It is one of the few aircraft where the primary controls are still mechanical and connected directly to the control surfaces - albeit with additional actuators such as the trim jackscrews for automatic control where required - because it's so old.

No, it isn't. And when it is, that's called a Stabilator.

The "tailplane" referred to is the Horizontal Stabilizer. Or "Stab".

A vertical stabilizer is a "Fin". Because vertical stabilizer just sounds stupid.

An elevator is a smaller piece behind the stabilizer, and a trim tab is another even smaller piece behind the elevator.

Trim is trim, whether it's done gracefully with a dinky tab on the elevator, or by forcefully wrenching the entire stabilizer.

On a sunny day (Tue, 7 May 2019 19:57:26 +0100) it happened Tom Gardner wrote in :

It is irrelevant AFAIK because it is not about up/down but about difference between left right , and front back, pitch roll. I for example am using the MPU6050

basically a 3 axis gyroscope and 3 axis accelerometer in one chip with i2c bus. Notice the 'gyroscope' part.

Wrote drivers for it and played around with it, even wrote a open GL based demo not sure where it is...

For the gyroscope part the acceleration Gs you make do not affect it, but the accelerometer part will show you their magnitude and direction.

The interesting issue for me was if I could use it as inertia based navigation system, so to replace GPS basically. There the long term drift becomes an issue, mainly due to stresses on the PCB and chip due to temperature fluctuations. You'd have to put the whole chip and board in an oven to get anywhere usable results...

I think by now there are many more of these type of chips.

You can make zero G with a drone too (have it fall a few tens of meters), and pull some when going up or on an angle, thing stays neatly horizontal.

But only when instructed to do so by the third pilot who was just along for the ride and obviously he did not want to die. He figured it out and told them how to regain control. The implication is that whatever the sequence of events was on the flight deck when MCAS goes rogue it is sufficient to overwhelm a two man flight crew with alerts and alarms. I suspect that bad HCI user interface has played a part in these crashes. (including making the AoA sensors disagree indicator an optional extra)

The guy who saved the earlier Lion Air flight leg from disaster should be a very important witness in the crash enquiry into MCAS behaviour.

More so when taking off from a high altitude airport with less lift.

I'm not sure the second crew ever stood much of a chance as they were already in thin air at take off and surrounded by even higher mountains.

That is also surprising. I guess we have to wait for the final report.

--
Regards, 
Martin Brown