Originally Posted by silverstrata
(Post 10422776)
Clearly MCAS is not a runnaway trim condition, otherwise we would be reaching for the cut-out switches every time the speed-trim operated. I think some people here do not realise that the trimmer doing its own thing is operations normal. Silver However, when an AoA is faulty, it will continously indicate high AoA to MCAS. MCAS kicks in, but still get high AoA input so it kicks again.. and again.. and again.... |
Originally Posted by dozing4dollars
(Post 10422831)
I haven’t flown a 73 but on the 72 (if I recall correctly) during a runaway, the first instinctual response was to apose the runaway with opposite elevator. This ingaged the trim brake. The noise of the brake verses the runaway trim was a giveaway to use the cutout switches. I don’t think this would happen as the MCAS does not activate the brake. All that sim training on runaway stab wouldn’t help because it’s not a runaway. The stall horn and stick shaker would make pulling back and trimming nose up counter to all training that a pilot receives from initial stall recovery in a Cessna with a stall horn through to transport aircraft. Two responses to two different stimulus. One Stall Recovery and one Unreliable Airspeed mask the third undocumented MCAS. To learn anything from any accident you need to have empathy for those involved. Not just the pilots but the line mechanics, Boeing and FAA engineers. The true villains, senior management, board members and yes, even politicians will never be held accountable The USA government shutdown that both political parties participated in was also a factor. ... and hence, the voters like you |
Originally Posted by megapete
(Post 10422844)
I also wonder if the forward position of the engines, which gives a pitch up moment at high angles of attack, and led to the addiction of MCAS, could possibly give a pitch down moment at low angles of attack?
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Originally Posted by Azgalor
(Post 10422863)
How the engines do that? What is supposed to be a problem? I expected that power and placement of engines creates this pitch up moment. Is it something aerodynamics related?
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Question: does the 737Max have a Q limiter on the elevator deflection? |
Originally Posted by Azgalor
(Post 10422863)
How the engines do that? What is supposed to be a problem? I expected that power and placement of engines creates this pitch up moment. Is it something aerodynamics related?
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Originally Posted by dozing4dollars
(Post 10422868)
Question: does the 737Max have a Q limiter on the elevator deflection? |
Dynamic pressure?
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Originally Posted by gearlever
(Post 10422876)
Dynamic pressure?
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Question: at what angle between stabilizer and elevator does the tail plane stall? |
I wondered why Boeing named their newest version of the successful 737 MAX. So I did a quick internet search and here is what came up:
https://www.airlinereporter.com/2011...s-the-737-max/ Here is an extract from the article: "Yes, I understand the ideas behind Boeing choosing this name, but it doesn’t mean the name works. During the press conference announcing the re-engined 737, Nicole Piasecki explained why Boeing chose the MAX name. “We wanted the name to capture how exceptional the 737 is not only to in terms of its performance but we wanted it to be able to differentiate the 7, 8 and 9. We wanted to make sure the name was easily identifiable from 4-year olds up to 90-year olds and we wanted to make sure that it represented the best that it will truly be… We thought about how do you convey superiority, the best, the gold standard in single-aisle airplanes. And how do you come up with a name to describe already a great airplane. We wanted to make sure that it talked about what it was going bring to the industry in terms of maximum benefit, maximum competitive advantage for our customers, maximum value and absolute maximum in what an airplane could deliver to our customers. So we came up with something that fit that and we will be calling this airplane the 737 MAX.” I do wonder whether after all the who ha is all over the air traveler will be asking whether it is a MAX they are about to board or even worse check before they buy the ticket. |
737 MAX scandal: Boeing putting profits before safety
https://www.marxist.com/737-max-scan...ore-safety.htmA similar process of “soft corruption” and conflict of interest can be seen in the financial industry in various countries across the world, made worse by deregulation. The Airline Deregulation Act of 1978 started a process of removing government controls over the airlines and manufacturers in the USA. This was done to encourage competition and lower the ticket prices, but the end result has been the monopolisation of air travel to the point where four major carriers control 80 percent of US air traffic. Tickets did become cheaper but travelling by plane has generally become a miserable experience worldwide and the workforce – from pilots and cabin crew to dispatchers, baggage handlers and office workers – is more exploited, underpaid and demoralised than ever. |
Originally Posted by canyonblue737
(Post 10422856)
Yes, clearly different than a runway and yes, the column cutout doesn't work with MCAS. Yes the trim wheel moving, even in manual flight, even when not trimming with the yoke switch is normal in a 737. That said you would think in 7-12 minutes of watching the nose get heavier and heavier and the trim moving downward on occasion on its own you would kill the trim with the stab cutout switches. I totally get the anger at Boeing but experienced 737 pilots should be able to figure this out, in particular with a bit of time, and after the Lion Air accident and the required reading of the MCAS system and its failure mode you would think any 737 MAX pilot would be able to figure this out very, very quickly let alone with time. Lots of blame to go around here in these accidents, starts with Boeing but as usual it ends in the point end of the jet.
Exactly!! There is a large range in pilot skill level and dedication. The most dedicated group I personally flew with was Japanese pilots at a small airline based out of Tokyo. They knew the aircraft systems backwards and forwards. They had their own study sessions and they also kept records of the expat Captains qwerks and briefed each other on those also. Was not unusual to pick up one of these young men who had a total flight time under 300 hours. And yes it showed but they matured rapidly and became very skilled pilots quickly. but back to the question at hand.... Yes, there will be enough blame to go around and I really like Boeing and am sad that they let this happen to them. I have sympathy for people who work for unenlightened airline managements that let politics and favoritism trump safe operating decisions. There are people who are a danger to themselves and others and truly do not know it. I hope that on the positive side, this accident has drawn enough attention that ALL are watching and learning. If the 737 MAX or any other aircraft can be flown out a corner of the envelope from which recovery is not possible we need to know about it and fix it. BTW, my personal standard for releasing a pilot to line flying was simple. I imagined my family in the back and had him fly the entire let down and approach without the autopilot or auto throttle Very few had much problem with this. We trained for this, everyone was familiar with the power and attitude required for every common configuration. |
Originally Posted by dozing4dollars
(Post 10422890)
Question: at what angle between stabilizer and elevator does the tail plane stall? |
Originally Posted by dozing4dollars
(Post 10422890)
Question: at what angle between stabilizer and elevator does the tail plane stall? well, as you stated before, that depends. the angle would be pretty small at Mach 1 . ;-) |
Originally Posted by Azgalor
(Post 10422863)
How the engines do that? What is supposed to be a problem? I expected that power and placement of engines creates this pitch up moment. Is it something aerodynamics related?
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Originally Posted by jagema
(Post 10422900)
Underwing-mounted engines, being under the center of gravity, create a pitch-up moment when adding thrust. Pitch-down when reducing thrust. Easy to picture: letter T. Push the lower end of the vertical line, that'd be the thrust vector. The junction of the T (where vertical meets horizontal axis) being the CG, it'll swing the whole thing clockwise.
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Originally Posted by jagema
(Post 10422900)
Underwing-mounted engines, being under the center of gravity, create a pitch-up moment when adding thrust. Pitch-down when reducing thrust. Easy to picture: letter T. Push the lower end of the vertical line, pushing force being the thrust vector forward. The junction of the T (where vertical meets horizontal axis) being the CG - The whole thing swings clockwise (nose up).
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Originally Posted by Chesty Morgan
(Post 10422808)
Ever flown a 737?
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Originally Posted by FCeng84
(Post 10422872)
Need you to describe what you mean by "Q limiter".
In ithe scenario where an aircraft is low and fast the elevator deflection available is limited. It should be noted that elevator deflection is based on deflection from the trimmed position of the stabilizer. |
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