snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@googlegroups.com:
It was FAA mandated adjustments. They needed to be there for oversight. Boeing cannot facilitate those changes without those entities on hand at the time.
You seem almost as thick as Larkin and krw. Strange too as you occasionally exhibit inklings of intelligence.
Or maybe you have never worked for a government contractor in an industry where there is 100% oversight of systems, and particularly those of mission critical status.
snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@googlegroups.com:
He did understand. He did NOT understand how to turn off the control system. THAT is where the failure is.
It is like hanging a weight on the handlebar of your bike, It will always pull to that side and you will always have to correct for it. That is within the control loop.
This undulation is obviously two controllers vying for the same control, and the one that was human was unable to disable the one that was fighting him... and likely also panicked, and took the craft outside the envelope of control ending in a catastrophic undulation that introduced the craft to the ground many miles short of its destination.
The graphs the news channels were showing were climb rates, not actual altitude graphs.
And when all that is happening, there were likely a couple loose passengers and crew that cause additional inertial problems for the pilot as well.
In this particular case, Trump's demand for funding for his border wall was unreasonable, and the other party's unwillingness to cave in to his irresponsible and irrational demands was entirely justified.
If you can't get stuff approved, you can't put it into aircraft. No inspector - no approval.
On Saturday, March 16, 2019 at 12:53:41 AM UTC-4, snipped-for-privacy@gmail.com w rote:
it under the wing with the "short" landing gear. I suppose extending the l anding gear is a big deal, so they simply moved the engines in a way so the y wouldn't hit the ground. They also made the bottom of the engine flat ra ther than arbitrarily round. I recall they made a big deal about the flat bottom as if it were an amazing piece of engineering.
nter of gravity. If the center of force of the engines is raised, if all e lse is the same, it will tend to push the nose down while someone said it w ould tend to push the nose up.
e center of force of the wind resistance of the plane. That is what the en gines are pushing against.
of the 737. The engines were a big part of this. Many things in a design are trade offs. There are very few perfect designs where all parameters ar e optimized. This is the situation here. They needed the larger (read "ta ller") engines to make the craft cheaper to fly.
These crashes are burning through the lifetime/fleet savings of all these o ptimization tradeoffs
This led to compromises in various areas reducing some performance functio nality. Specifically it has been said the engine changes tended to push th e nose up, so the MCAS was added to adjust for that.
the MCAS was simply added to help prevent stalls on takeoff after retracti ng the flaps. It just doesn't seem right they would bother with an active device like this to compensate for an unbalanced plane. I expect they woul d adjust something else in the design to balance it out.
It is planes centre of gravity plus a bunch of net forces and torques relative to that reference datum. There must be something odd about their disposition that changes significantly as the flaps are retracted.
MCAS = Manouvering Characteristics Augmentation System is marketing speak for engineering bodge. Lets hope they can get it right this time.
They should have designed it to be failsafe then. Having a control loop that can go rogue so easily in a civilian aircraft is utter madness.
They have the black boxes in Paris for analysis now although they are pretty badly smashed up and found the horizontal stabiliser jackscrew in a nose down position just like on the ill fated Lion Air flight.
Yes it is. I am certain that there were engineers who lost sleep about this issue and tried to bring it up with management. Unfortunately, the way corporate corruption works they will likely be the targets in the investigation.
See how they blamed the guy for the GM ignition switch:
And to follow up to my last post about this madness (and it is).....This ki nd of madness can only be corrected by blaming the top levels of management for allowing such awfulness to be hidden from them (by corporate design) This should really wipe out the top 3 layers of management across the whole company because it indicates technical corruption which is so blatant that it could have only happened by a terrible management team that encouraged this nonsense by their culture. In other words this points to a corrupted culture .
kind of madness can only be corrected by blaming the top levels of manageme nt for allowing such awfulness to be hidden from them (by corporate design) This should really wipe out the top 3 layers of management across the who le company because it indicates technical corruption which is so blatant th at it could have only happened by a terrible management team that encourage d this nonsense by their culture. In other words this points to a corrupte d culture .
n
My daughter just got her civil engineering degree. I have always told her that the building that fall down were the "over-engineered" ones. This pla ne was an over-engineered plane. Too clever by half comes to mind. Arroga nt people who think they can overcome the fundamentals of flight through cl ever control loops.
It is bad idea. The pitch moment from the engines turns the airframe the wrong way.
There are water airplanes of the flying boat type with the engine(s) high up, to keep out of water. The pitch changes with power changes are not funny.
Tauno Voipio wrote in news:q6jll0$ajb$ snipped-for-privacy@dont-email.me:
I am sure that would make them even more of a joy to service too.
The alternative design is to have the wings over the fuselage. But that ruins the upward view!
The C-17 is 'wing-over'. It also has a nice feature called "blown flaps". This is where the engine blast is directed right into the wing and flap, unlike most designs. The first time the test pilots flew it they were amazed that it has zero "squash effect" when landing. The plane lands exactly where it is aimed and the zero squash suprised the hell out of the test pilots. It is due to the blown flaps.
it under the wing with the "short" landing gear. I suppose extending the l anding gear is a big deal, so they simply moved the engines in a way so the y wouldn't hit the ground. They also made the bottom of the engine flat ra ther than arbitrarily round. I recall they made a big deal about the flat bottom as if it were an amazing piece of engineering.
The engines were moved forward and up and the nose landing gear extended 8"
nter of gravity. If the center of force of the engines is raised, if all e lse is the same, it will tend to push the nose down while someone said it w ould tend to push the nose up.
e center of force of the wind resistance of the plane. That is what the en gines are pushing against.
afaiu the problem is only at high angles of attack where the the bigger nacelle in front of the center of gravity starts to generate lift pulling the nose up
The engines mounted under the wing generate a pitch up moment. At high thrust with the flaps raised, this could cause the A/C to stall. MCAS was added to pitch the nose down and prevent the stall.
Unfortunately, MCAS could not distinguish a faulty AOA sensor reading and kept increasing the stabilizer jackscrew to full nose down. This applied so much force that the pilots could not overcome it and raise the nose.
The solution was simple. Turn off the automatic pitch control. There are two switches directly in front of the pilots that turn off the automatic pitch control, but the pilots were not informed how to use them. The erroneous AOA sensor also caused other errors and warnings in the cockpit that made it extremely difficult to figure out what was going on and the corrective action needed to solve the problem.
Here are a few videos that explain more about the problem, as well as the position of the two switches needed to turn off the MCAS:
Boeing 737MAX, LionAir Update!! - MCAS?
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Boeing 737 Stall Escape manoeuvre, why MAX needs MCAS!!
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EMERGENCY AIRWORTHINESS DIRECTIVE
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Crash: Lion B38M near Jakarta on Oct 29th 2018, aircraft lost height and crashed into Java Sea, wrong AoA data
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Lion Air B-737 Max MCAS UPDATE 28 Nov 2018
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Lion Air 610 Disaster and Boeing Emergency Airworthiness Directive 7 Nov 2018
Just to clarify, there are two flying surfaces that control the aircraft pitch. This makes it go up and down.
The stabilizer is the front part of the small wing at the rear of the A/C. It is controlled by a jackscrew and is used to trim out variations in center-of- gravity due to passenger loading, c/g variaations due to fuel burn, and in the MAX, variations in pitch due to engine thrust.
The rear portion is the elevator, which responds to changes in the yolk. This is used to control the pitch when maneuvering, such as making banked turns. This is needed to keep the centrifugal force acting on the passengers vertical with respect to the A/C so the passengers are not tossed side-to- side. This is called a coordinated turn, and if done properly the passengers won't even notice that you are banking the A/C.
Unfortunately, the stabilizer is larger than the elevator. So if the MCAS says to go down, you go down.
sly neutral engine nacelle generates lift. A lift which is felt by the airc raft as a pitch up moment (as its ahead of the CG line),... The aircraft?s inertia can then provoke an over-swing into stall AO A. "
olving two parties. You can't solely blame one party.
as unreasonable, and the other party's unwillingness to cave in to his irre sponsible and irrational demands was entirely justified.
Do you? Engineers don't need a government inspector looking over their sh oulders while they work.
ctor - no approval.
It has been quite some time since the shutdown was over. Obviously the iss ue wasn't that Boeing did the work and was just waiting for approval. Also , I've seen it reported that Boeing stopped working on the fix during the s hutdown as if the government had to be part of the team doing the work.
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