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Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]20

Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

(OP)
This post is the continuation from this series of previous threads:

thread815-445840: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 1]
thread815-450258: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 2]
thread815-452000: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 3]
thread815-454283: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 4]
thread815-457125: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 5]
thread815-461989: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 6]
thread815-466401: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 7]

This topic is broken into multiple threads due to the length to be scrolled, and images to load, creating long load times for some users and devices.
If you are NEW to this discussion, please read the above threads prior to posting, to avoid rehashing old discussions.

Thank you everyone for your interest! I have learned a lot from the discussion, too.

Some key references:
Ethiopian CAA preliminary report (Link from Ethiopia is now broken. See link from NTSB Investigations below)

Indonesian National Transportation Safety Committee preliminary report

NTSB Investigations

NTSB Safety Recommendation Report: Assumptions Used in the Safety Assessment Process and the

Effects of Multiple Alerts and Indications on Pilot Performance

A Boeing 737 Technical Site

Washington Post: When Will Boeing 737 Max Fly Again and More Questions

BBC: Boeing to temporarily halt 737 Max production in January

Pulitzer Prize, For groundbreaking stories that exposed design flaws in the Boeing 737 MAX that led to two deadly crashes and revealed failures in government oversight.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Part 8 is appropriate, since it appears Boeing is now referring to it as the 737-8 not MAX8.

An attempt at rebranding, hoping people don't connect the old and the new, I suppose.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I thought that there was talk of rebranding early on and that Boeing stated at that time that it would not happen.
Does anyone remember that or am I mistaken?
I won't say that I will never fly on a Max8.
I have decided that I am willing to pay an extra 10% to 20% or more to fly on another plane.
How much exactly will be determined at ticket time, but at least 10%.
Rather than trying to determine exactly which model is scheduled for a flight it will be safer to avoid all Boeing products as far as possible.
I suspect that I may not be the only person who thinks like this.
Good luck with rebranding, Boeing.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Waross, you are absolutely not the only person thinking like that, except flying safely might mean me not flying at all. I also think that paying a premium for the "privilege" of safe flying is certainly not fair to us guinea pigs at this time. I'm thinking more like a 60% DISCOUNT! for at least a full year of fleet operation is in order while they rebuild their reputation and our trust. I for one am not in the mind frame to trust Boeing the FAA, or the CDC, DOJ, USPS, or even Fish and Wildlife Service for that matter, until there is a change of government. That's just how it is now. Fortunately I have alternatives.

Let's see how long it takes the airlines to drop the "-8". I'll bet they will never make any distinction at all.

“What I told you was true ... from a certain point of view.” - Obi-Wan Kenobi, "Return of the Jedi"

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

(OP)
Yes, I remember the re-branding discussion a while ago - which circulated primarily in the media and wags like us, not Boeing.
I'm not a marketer, but my guess on the strategy: You don't re-brand while the product is still broken.
You re-brand when (you hope) it's fixed.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

(OP)
Boeing actually made some sales. To a polish airline, reportedly. Not a large number, but any amount > 0 is "infinitely" better.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Any sale to a polish airline is a LOT.

*rimshot*

I'll see myself out.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

The name 737-8 is actually it's proper certification name.

Max is the series name. So there is 737-7 737-8 737-9 and 737-10 under the max name. But for official purposes they are called those. All the certification paperwork will use those designation. There is another sub type for Ryanair with extra emergency exits to cram more people in. It will have another code when it eventually fly's.

The 10 hasn't been certified yet at all.

It's like the A220 was called the cs100/cs300 but now it's A220. But all the paperwork calls it a BD500 and that hasn't changed.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

(OP)
From what I have gathered, many senior people in Transport Canada developed their own views (ref. 1, 2 below) about the causes and required remedy for this aircraft, quite independently of the FAA and Boeing. Over the year and half of the re-certification process, it seems like both FAA and Boeing have evolved their positions closer and closer to the positions taken by Transport Canada early on. It is encouraging now, that Transport Canada will be able to test their positions on the actual aircraft and confirm.

1 Transport Minister Marc Garneau said on Wednesday that the planes would be grounded “for as long as it takes” and pilots should experience the fixes Boeing is devising in simulators instead of relying only on more basic, computer-based ground training.

2 “MCAS has to go,” a manager at Canada’s aviation regulator said in an email to global peers

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I think Transport Canada also want a method of killing the stick shaker without pulling CB's.

The training is going to be very interesting to see what they come up with. I suspect in EASA land its going to require separate training and checking to the NG.

Also they won't have developed the new QRH yet or procedures until the systems are finalised.

BTW just finished 100 hours on the A220. Nice machine and well thought out human machine interface. Handles lovely.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

(OP)
You're right. Thanks for reminding me. They did ask for added means to reduce the distractions during prolonged emergencies.

Jealous about the A220 time. Are you referring to sim or actual airborne time?

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

64 hours of sim for the type rating, And 100 hours flying the real one. I did a Zero flight time rating for the second time in my career.

It fly's like a proper aircraft despite the FBW, thrust levers move when the AT is in charge of them.

The 94% thing above FL290 on the engines is not such a big deal. But that could be because on TP's we were used to doing our own power in the cruise anyway.

Still on the learning curve with energy management in the decent. I have only once managed to do a flight idle from FL400 to landing configuration then power up for Vref +5 on the ILS without the power coming up or having to use speed brakes before than. But its getting more economic and smooth the more approaches I do. Strangely enough I am better at landing it at night than during the day. Still have to remind myself I don't have the Q400's 6 deg pitch tail strike limit or need to keep the power on during touch down anymore.

Only done one auto land on the aircraft which was easy enough and worked and its landings are firmer than mine. Have to get another 50 sectors before I get my restrictions on low viz operations removed but plenty of time before the fog season starts again.

But as an aside and comment on training for aircraft. I did 130 hours ground school training for the A220 and 16 4 hour sim sessions, of which 4 4 hour sessions were in a fixed base procedural trainer, 9 in a full motion sim (well for us it was the same sim but the motion was turned on), 1 session low vis approaches. 1 skills test and 1 session doing circuits for the zero flight time rating. And 20 line training sectors with pax in the back the first 4 were with a TRE to complete the zero flight time rating. It took 3.5 months and I think you lot could see the state of my stress levels through various post beer posts during it. But be warned I have 4 days off coming up day after tomorrow. But my stress levels are now much much lower now everything is completed and signed off. Well for another 5 months when I will be in the sim again when they will expect everything to be a lot more slick.

To note they claim the A220 is memory item free.... its not really but the items could be called normal flying procedures which should be done anyway and some relate to the Autothorttle being out due to this 94% restriction. What it does have though is poo loads of operating restriction numbers you need to remember. Max tailwind for engine start 18knts, cold weather temperature's (already decided -40 deg C and get the book out with them), most of them are to do with the engines with these large fans and inlets. By far the largest amount of any type I have flown.

The ECAS checklist and alerting system is an utter dream to have and use. I haven't had a problem in the air yet to use the none normal checklist side of things in real life, works a treat in the sim though. The MEL is a bit interesting though, and will I suspect it will take a few screwups with it until I get my head round it.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Looks really nice.

“What I told you was true ... from a certain point of view.” - Obi-Wan Kenobi, "Return of the Jedi"

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

You should see the toilet in it!!!! On the Q400 it would need to be an emergency before even contemplating going for a dump on it. Going for a pee had its technical issues for a 6ft bloke. Going for a sit down ran the risk of appearing in the cabin with your trousers down.

Actually the toilet and isolation of air in it. Although not a regulatory requirement has had a lot of thought and engineering go into it. Never mind the artistic merits of what they have done.

Big change in LGW when I was in there last week, its like a grave yard of Easyjet and BA aircraft. No traffic on frequency, tower doing ground and clearance delivery. Only 1 fuel bowser doing the whole of the airport.

Straight in no pissing about from ERING.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Yeah. That's important!!!!
So they really did think of everything.

“What I told you was true ... from a certain point of view.” - Obi-Wan Kenobi, "Return of the Jedi"

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

They have even bolted the pilots seats to the same bit of structural metal as the nose gear.

This allows every single light to be felt by your bum.

So in low Viz you know your on the centre line and your speed by your bum jiggle. And you can taxi to the apron without seeing a thing out the window by Braille.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Back to the future, flying by the seat of your pants. I like it up to that last bit. Like the misplaced baggage cart!

“What I told you was true ... from a certain point of view.” - Obi-Wan Kenobi, "Return of the Jedi"

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Joking aside they have built a very nice aircraft.

It's real shame that they have stopped doing commercial aircraft.

They have also put a lot of thought about how a pilot interacts with it. They have done the same thing in the cabin for both pax and cabin crew.

The thing just sips fuel to boot.

Fl400 at ceiling weight limit at M0.78 and she was burning 1550 kg an hour at 90% N1. The none geared engines on A320/737-800/emb195 burn in the region of 2600kg an hour but with more pax.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

It's a shame the way the Canadian aviation industry was/has been marginalized over the years. A little over 60 years ago they produced a world class air superiority weapon that was unfortunately stillborne.

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Well the guys that have flown all three fbw A320, A220 and emb195

Reckon the A220 is the clear winner from a pilot flying it pov.

Yes it is a shame leaving only two OEM both of which seem intent on keeping all the old gear on life support until they really have to modernize it.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Quote:

Yes it is a shame leaving only two OEM both of which seem intent on keeping all the old gear on life support until they really have to modernize it.

My guess is the boeing claim to move to south carolina was a practical protest against the 1 billion tax. If initiative #35 passes and the tax is revoked, then boeing might change their mind, but it would increase the pressure to change the washington constitution to allow income taxes, at least on a county basis. "...when logic, and proportion, have fallen, sloppy dead..." Grace Slick RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Just got this... Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] The 737 sim is commonly used for checks when you go for jobs even if its for a turboprop. Its also used for doing a course in Euroland called the Multicrew cooperation course which is about working together as a team and communicating not flying the aircraft type your using the sim of. We do it before the first multicrew type. This is mainly due to the huge numbers of 737 sims and also the availability. So most of us at some point have flown the 737 sim in a very reduced form. As you can see from that pic there is buttons and switches everywhere. But that doesn't give the full picture. You have the over head panel. And then the infamous CB panel. This is the main one behind the LHS but there is another smaller one behind the RHS. There is quite a few QRH procedures that require you to find a CB on those panels using a grid allocation and pull it. Which is what the stick shaker cancellation discussion is all about. One pilot has to get out of there seat to find it and pull it. And as you can see by the cockpit picture there is no space left to put a button. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] @dik, artist didn't manage to label the powered trim cutout, did they. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] @moon... Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] moon there isn't on one in the max apparently there is only a electrical trim motor isolate which covers both flight control mandatory inputs and electrical manual trim control. Unlike the NG. Once its off your on your own...... if you are inside the +- 10 knot window you can actually physically trim in....if your not you need to turn it on again against the QRH to actually survive. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] 2 (OP) Fixed that for ya. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Hehehee... Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Love it spar RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Talk in the other thread about flying a plane with a loose elevator and a trim tab reminds me of a friend who had dinghy with a main and jib, a Laser II I think. He misbehaved somehow and his mother hid the rudder so the set the main and steered with the jib. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] So that's where they hide the Chemtrails control! RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Boeing orders: Boeing had no orders for new airliners in October, its second consecutive month, and orders for 37 of its Max jets came off the books as the company continues to struggle with the grounding of the Max and a pandemic that has crippled the airline industry. Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] I no longer trust the certifiers... I would avoid them... Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] 15% tariffs just got applied to all delivery in EU. To be honest I can't see then flying in EU for two years anyway. The biggest owner Norwegian is likely to go tits up soon. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] I really don't care how safe the plane is. I do not trust Boeing. I will pay a premium to avoid flying on any Boeing aircraft. Bill -------------------- "Why not the best?" Jimmy Carter RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] I wouldn't fly on the max.... The rest of the 737 fleet no problem. The only other reservations on Boeing types would be to do with etops and engine types. Which isn't really Boeing's fault. If it's a 747 or 757 proper old school Boeing aircraft go for it. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Now we're talking RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] 2 It's not just the plane, Alistair. I have no trust in Boeing's honesty or corporate values. They screwed up and killed 189 people. That was bad enough, but instead of taking immediate corrective measures they stonewalled and refused to act in a morally acceptable manner. As a result of their failure to act, they killed 157 more people. I try to avoid doing business with people who are so willing to put my live at risk for financial gain. Bill -------------------- "Why not the best?" Jimmy Carter RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] To be honest I wouldn't put any more trust in anyone else in the industry be it the operators or the OEM's RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] https://canadianaviationnews.wordpress.com/2020/11... But I suspect its not going to be a boon for the bank balance as they think. I suspect it will force a number of airlines into bankruptcy if they insist delivery on their schedule unless they sink the finance onto Boeings books. Lets hope to what every deity you prefer that one of them doesn't crash in the next year. The situation is utterly ripe for a none related crash to the certification issues. Aircraft sat on the ground for 18 months plus aircraft really don't like being on the ground. Expect a huge list of gear, electrical and flap issues over the next 6 months. Its nothing to do with the original issues with the MAX just long term storage. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Here's the announcement https://www.faa.gov/news/updates/?newsId=93206 The AD runs to 115 pages(!) https://www.faa.gov/foia/electronic_reading_room/b... I'll let someone better qualified than me digest that. Talks about adequately separating airplane wiring and has emasculated the MCAS system, so it is now virtually useless as far as I can see (lower stab angle movement, only operates once per flight high AOA and then resets) and can be held against by column movement. Plus all the checking one to the other (5.5 degrees difference it all shuts down) The AD seems to be addressing all the comments and issues raised by the various parties. Looks like the stick shaker is still there. Basically it's all about - we've fixed MCAS from going off so now we don't need to do anything to address the other issues which appeared along the way.... Remember - More details = better answers Also: If you get a response it's polite to respond to it. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] LittleInch... I think that Alistair summed it up, "Lets hope to what every deity you prefer that one of them doesn't crash in the next year." I still won't fly on one and wonder what companies would purchase this somewhat tarnished craft. Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] The argument seems to be that yes you need MCAS in order to meet the requirement to have increased force on the controls as you pull back at high AoA when everything is working as it should. However if MCAS is inoperative ( now for multiple reasons), this is OK as this apparently this single fault does not prevent "continued safe flight and landing" and that the pilot can stop the plane increasing the AoA and therefore potentially going into a stall by pushing forward on the control column(!!). WOW There's no particular mention I can find of how they have managed to reduce the amount of nose down trim required from previous to now and still have the same effect. It seems any deactivation also kills the Speed Trim system. I've never quite worked out what this does, but is that an issue now? They dismissed the return to the two switch system as now not being required because they've made the system so safe and also dismissed the force needed to manually trim the plane for the same reason. Also they state that they don't believe the manual system can't be used. So there we have it. Remember - More details = better answers Also: If you get a response it's polite to respond to it. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] So, you are saying that if it activates and you don't need it, you can disable it, and you can fly the craft fine without it... have to shake the sawdust out... Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] (OP) Well, as the news has trumpeted all morning, the AD has been revised with a means of compliance: a series of service bulletin remedies and training requirements to be fulfilled, then the planes can reenter service in the USA. Europe has indicated that they're not far behind, and Canada has sent mixed messages, both acknowledging that the process is nearly complete, but at the same time it's not good enough, yet. I can't square the circle on the necessity of the trim VS the necessity of the flight control feedback forces, the issue that started it all. Plenty of other issues that have reared up, such as pilot training (in sim's or on the sofa) cockpit advisory confusion, ability to disable items such as the trim and the stick pusher, the stab's range of motion, the might and muscle needed to turn the trim wheels, and the proportional feedback that the yoke is supposed to give the pilots - and that's just off the top of my head (I may have missed some important ones). At this time, Boeing and their operators have access to the maintenance and upgrade data that defines what changes are required before flight. They don't so much define what needs to be done, but instead they "embody Alert Service Bulletin #####" and so on, which cross-references to a document I don't have. The general public only has the records published so far from the FAA, which don't shed much light, yet. I'm still looking. Trust Dominic's team in Seattle to get their hands on it soon, and offer us a run-down. It ain't over yet, I bet. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Dik, What it means is that if mcas goes off when it shouldn't then the reduced angle it now moves the stab compared to before (I can't find out how much less) can be over identify by pulling the control column alone. This gives the pilots time to figure it out and trim the stab back into the right position. Then unless the AoA goes back to normal mcas shouldn't keep going off. But if mcas is disabled and you go into one of these high AoA situations that is now ok as the pilot can stop the plane going into a stall by pushing forward on the control column contrary to the normal requirement about increasing force as the AoA increases. I presume the fault then needs to be fixed before the plane can fly again Remember - More details = better answers Also: If you get a response it's polite to respond to it. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] new news: "After nearly two years and a pair of deadly crashes, U.S. Federal Aviation Administration has cleared Boeing’s 737 Max for flight. The nation’s air safety agency announced the move early Wednesday, saying it was done after a comprehensive and methodical 20-month review process. Regulators around the world grounded the Max in March 2019, after the crash of an Ethiopian Airlines jet. That happened less than five months after another Max flown by Indonesia’s Lion Air plunged into the Java Sea. A total of 346 passengers and crew members on both planes were killed. The planes won’t return to the skies for a while. The FAA says it must approve pilot training changes for each U.S. airline and airlines must perform required maintenance on the planes." Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Quote (What it means is that if mcas goes off when it shouldn't) Thanks... my mistake... I was trying to be cute... Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Speed trim system was another fudge to correct dodgy aerodynamics as far as I can tell. They don't have to actually correct all these issues just prove that there is 1 to a very large number that the issue will not cause a fatality. Half the stuff apparently they couldn't force them to change because there is no regulation that requires it to be so. eg the manual trimming and stick shaker stuff. They are all going to be inspected as well for production debris and also some lightning conductivity stuff By FAA engineers not Boeing. This may throw up other issues. There is also a rather large wiring mod to be done. There is apparently legal stuff with law changes currently going on to do with the FAA which might also have had an effect. Personally I think they had basically hit the end of the road with the changes they could make and not scrap all the aircraft that they have already made. We shall see what the other regulators com up with. I have a gut feel something may come up when the FAA starts doing airworthiness inspections. But as I have said before its the long term storage issues which concern me the most after it starts flying again. Gear issues, flap issues, fume events, bizarre electrical issues etc. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Do I understand that there just has to be a manual trim system, but there is no regulation saying that it has to be usable when it is really needed? There are all sorts of justifications and reasons and arguments but at the end of the day, the more you need manual trim, the less likely that it will be possible to use. Would a usable usable manual trim have significantly lowered the body count. What would the late Dr. Richard Feynman have said if he had been part of the discussions? I am sure that he would have asked some questions that could not be answered by the proponents of the existing manual trim system. Bill -------------------- "Why not the best?" Jimmy Carter RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Waroos, That's our interpretation of it - it turned out that there was no actual set down requirement for the amount of force required to turn the trim wheel or how many times you need to turn it to get 1 degree of movement. Hence the FAA can't make up a rule so are left with nothing to use to get Boeing to change anything. The diameter of the wheel apparently changed somewhere along the line, possibly into the NG to cope with changes to the cockpit layout which reduced the mechanical advantage. It apparently takes 15 turns of the wheel to make 1 degree of stab change. Now whether there is a requirement for a manual system or just some level of independent back up I don't know. I don't know what the airbus set up is for the stabiliser, but I think it's similar. The 737 apparently had back up motors at one time but they got removed in later versions. I think the answer to the "Would a .." is most definitely Yes, at least for the second crash. The poor Ethiopian pilots apparently tried to move the stab manually after they disabled the trim motor, but couldn't move it, not helped by their high speed. That's why they turned the trim motors back on and then plummeted into the ground. Only one pilot could try this as the other was holding the plane just about horizontal with both hands. Later on the "roller coaster" method was noted as being removed from the manual which released some of the tension on the stab in a dive before you pulled up and then tried again. Remember - More details = better answers Also: If you get a response it's polite to respond to it. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] #3, will be more interesting, with what has happened. Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] I am pretty sure but not 100% that the airbus trim is operated by a backup hydraulic system which is powered off an emergency bus. The main system has 3 electric motors and then the 4th backup system which has multiple electrical power sources. I think the only thing which doesn't have more than three backup methods is the actual main screw jack itself. But as the elevators are hydraulically powered with 3000 psi and there is 3 hydraulic system which power them as well even if the stab becomes locked you can still move the elevator and fly it. The only way they get away with FBW is by having at least triple of everything that's involved in primary safety. The new generation of FBW goes even further. the A220 has 6 AoA sensors. But I might add we still don't have an AoA indication on the instruments in the cockpit. The issues is that the 737 is now FBW with computer inputs into the primary flight controls but has none of the required FBW backups. Which is one of the reasons why I think they had a limit of how far they could push them to change things without scrapping every single aircraft that they had already produced. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] EASA has released its requirements. https://ad.easa.europa.eu/ad/20-184 They have also set a load of limits to perform low viz and autolands and also coupled RNP approaches . Which may cause Ryanair no end of problems. But the big thing is the Quote (EASA) Foreign AD: Federal Aviation Administration (FAA) AD 2020-24-02 dated 20 November 2020,which is not adopted by EASA. Which is to be honest the most worrying aspect. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] (OP) Yes, they have a few special features in their proposed new AD that the FAA didn't address. Looks like the circuit breakers for the stick-shaker need to be found in a hurry, so the normal procedure for this will become "pull the breaker". This is the kind of procedure that systems design has been working AWAY FROM for 50 years. I bet Transport Canada will get on board with this strategy too, given some of the other things they've said in the past few months. So I have to wonder, now, if the reliability level has been "rounded down" from the required 10^-9 to... maybe 10^-8.9. And stay out of the operations where you really depend on both high functionality and reliability at the same time (RNP for example). And everyone is just going to put up with it for now, maybe hoping that a more long-term fix can be finished a year or so from now. Proper DAL is not whipped into black boxes like magic, or overnight. Does that cover all the holes in the swiss-cheese? RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] There are more than a few QRH cards on the 737 that require CB pulls. The question is will this one need 1.5 meter long arms or get out your seat or not. I don't really understand what the problem is with the RNP stuff. Its all pumped through the same flight director logic as the ILS coupling. The fancy stuff is all done in the box of tricks doing error calculations and using the SBAS to get the high resolution both horizontally and vertically. But issues like this are not for stick monkeys like me to be worrying about. And it definitely won't and can't cover all the holes in the swiss cheese. There are still holes there from the initial 1960's design that have never been fixed. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] So, after a year of not flying passenger jets, do the skills of the average pilot get a bit rusty? "...when logic, and proportion, have fallen, sloppy dead..." Grace Slick RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Hell yes you can feel it after 2 weeks vacation. I am feeling rusty flying 30 hours a month. They will go to the SIM first but you don't get in the groove until your banging in 8-12 approaches a week. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] (OP) Quote (Alistair Heaton) I don't really understand what the problem is with the RNP stuff. Its all pumped through the same flight director logic as the ILS coupling. The fancy stuff is all done in the box of tricks doing error calculations and using the SBAS to get the high resolution both horizontally and vertically. I bet inside that box there is too much reliance on the same AOA vanes that got us into this mess. Sure you can correct it with the GPS but it's a correction of +/- applied to another number that's gone full-scale wacky. If the system still doesn't have the power of voting down the bad data... RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] As such it just provides a heading or a vertical speed to the flight director which the autopilot then gives control input instructions to a set of servo's to adjust the relevant controls. It will use the same screjack motor as everything else does to control pitch. There is no flight envelope protection on that side of things if it try's to do something stupid it will take the aircraft to the stick shaker. Which might be the reason, there was an issue with the stick shaker running and the autopilot not kicking out. Which wouldn't be fun at 100ft and the ground not insight a a go-around would involve the aircraft touching the runway. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Note that American Airlines flew their first 737MAX flight today since the grounding, with albeit non-paying customers, but for the first time, they were not American Airlines people. In this case, it was a group of reporters which were flown from Dallas to Tulsa. It appears that they will soon be making revenue generating flights. Delta and Southwest are expected to follow suit. John R. Baker, P.E. (ret) EX-Product 'Evangelist' Irvine, CA Siemens PLM: UG/NX Museum: The secret of life is not finding someone to live with It's finding someone you can't live without RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] What's your feeling for general feeling about the MAX your side of the pond? To be honest there is that little flying going on in Europe and Norwegian is utterly screwed. In fact I think the court case with Boeing is due to start soon over several billion dollars. Even if it was released to fly it wouldn't be in the air anyway I am flying around with loads that would be poor in a Q400 never mind a A220. I expect that most pax wouldn't know the difference between and Boeing and an airbus and if the safety card didn't mention the model then they wouldn't have a clue what they were on. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Quote (Alistair) I expect that most pax wouldn't know the difference between and Boeing and an airbus and if the safety card didn't mention the model then they wouldn't have a clue what they were on. An other possible issue may be rebranding. Even if Boeing doesn't re-name the Max, there may be a suspicion that some airlines may rename the Max. Then there is equipment substitution; the craft listed in the booking information may be substituted with a Max without notice. With that in mind, and with a healthy distrust of Boeing, some of us will be avoiding flying with carriers with Boeing fleets of any flavour. Bill -------------------- "Why not the best?" Jimmy Carter RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Commercial pressure is starting with Airbus now with the A220 Air France is trying to get Airbus to stretch the A220-300 already and its only been flying for a few years. They prefer it to the A320 NEO. And to be honest I don't blame them. The airbus FBW is decades old now and clunky compared to the Canadian product. Seems like Ryanair have ordered another 75 737-MAX-8200 but to my knowledge its not even certified yet for the additional pax numbers which require another emergency exit RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Whatever happened to the ryanair proposals to fly with only 1 pilot + 1 stewardess, passengers will have to stand, and pay to use the toilet? "...when logic, and proportion, have fallen, sloppy dead..." Grace Slick RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] That's just his normal bluster to get free advertising. He usually comes out with something every 6 months to get social media excited. I hope they put the video public of the pax evacuation tests with 197 pax trying to get out with only 50% of the doors working and no wing slides in 90 seconds. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] I recall one of the evac tests ( in 1975) where they recruited 197 college athletes to act as the passsengers, priming them for the fast reaction requirements , and of course they passed the 90 sec test. I guess they do not recruit patients from nursing homes to be the test passengers.I wonder how fast the evac is when half the passengers have dogs and miniature horses as their "comfort pets" . "...when logic, and proportion, have fallen, sloppy dead..." Grace Slick RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] I'm sure one of the trials / tests they did to re enact a poor real evacuation was to offer cash incentives to the first 50 people off the plane, regardless of where you were sitting to replicate the panic that could ensue in a fire / smoke situation. They discovered that the narrow gap in the aisle due to the galley caused a log jam of people, but not before there were a few broken bones and sprains as people vaulted over seats and basically forced themselves to the front of the queue. And that was a 737. Remember - More details = better answers Also: If you get a response it's polite to respond to it. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] The stuff that used to go on in the 70/880's to get through the certification was utterly horrendous. As you say it was a load of young males who had a bonus if it worked. Broken bones were common. 737 is particularly bad because it doesn't have wing slides. The evacuation drill needs the crew to select flaps to create a slide down to the ground. But that still levels a 6ft drop to the ground. In real life pax try and go back inside because they don't like the drop. If they forget to put the flaps out then its 10ft drop. But they banned that shenanigans and its now a mix load with some variation in gender and age distribution in the cabin, well it is with EASA anyway. In real life a lot of the time the under carriage has given way so things are lower. Or there isn't that much of a rush and people can just use the fore and aft doors. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] I've never fancied getting out the overwing exits on a 737, but at least now the door hinges upwards so you don't end up with 20kg of door in your lap. It always looked a rather err exciting way to exit the air plane. and the 800 and Max have two doors on each wing! Remember - More details = better answers Also: If you get a response it's polite to respond to it. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] I used to struggle with those wing exits during the yearly door training never mind the cabin crew. If you got the angles wrong you pulled a muscle in your back. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] I always got the take-away from the pre-flight announcement that; "We will be flying almost 4 miles high. There are six exits, two in the rear, two in the front and two over the wings." I always thought; "Great. If anything goes wrong we can get out and walk on the wings." Bill -------------------- "Why not the best?" Jimmy Carter RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] (OP) Last year an intern at my company was being shown the cockpit of a Dash 8. Various features were being pointed out and the "guide" pointed to the ceiling that there's an emergency exit hatch there. He actually reached up and pulled the handle. Well the thing dropped into his arms and there was a struggle with the mass of it in a confined area, and his guide trying to regain control of the situation. A very red-faced young man walked out of the plane (the point where I saw that something was up). And he was required to accompany his guide to the maintenance chief to explain what had happened and that the door would have to be reinstalled and checked. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] i got told in no uncertain terms to never touch it unless we were going to exit via it. It has a ventilation possibility which 50% of the time ends up with it dropping out. The guy was lucky he didn't hurt himself... RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] It's back... https://www.cnn.com/videos/business/2020/12/05/boe... Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] And as soon as they have one thing finished then another one turns up. https://ad.easa.europa.eu/ad/AIR-20-19 its a similar issue that airbus had when one went into the woods thinking it was in landing mode and refusing to come out of it apparently. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Alistair - Do you mean AF296? There was a lot of talk about this and I know certain things are disputed, but in that one the pilots really screwed it up and didn't initiate go around fast enough for the engines to spool up given that they were at idle for a long time before that. Or so says airbus and the accident investigators. But this one sounds not that good.... Remember - More details = better answers Also: If you get a response it's polite to respond to it. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] There is loads of disputed over that one And claims that the back box's had been tampered with. There is alleged to be 4 seconds missing. And if that 4 seconds involves a none responsive command for power. Then history would have been somewhat different. There were some major changes to the AT logic afterwards and changes to the pilot training. I think there was a Mayday episode on it. The main pilot issue is show boating and going below 500ft when not intending to land. The chain of events after that could have been stopped there. Even doing 500ft flyby with pax onboard wouldn't have passed my personal risk assessment of acceptable. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Without going too far off tangent that crash (AF296) was a real balls up from the start. But it's when you realise that they had the engines on idle for a long time (>30secs) and basically scrubbed off speed and height by gradually lifting the nose until they ran out of air speed then somehow expected the engines to give full power instantly. They lined up initially on the wrong runway, were too high and over confident. The engines were spooling up when they hit the trees but they take a few seconds and with a large bunch of trees at the end of the runway they didn't have those few seconds. I don't know what happens on a normal landing / go around but I would be surprised if the engines were at complete idle as you glide in or how long the power on from throttle movement to actually doing something takes. In a crash situation time slows down to a remarkable event for the participant to the extent that it is a known issue that people think something isn't happening as fast as they think it should (e.g. engines spooling up) and so either add more force or start doing something else before the machine responds as it should (reportedly moving the throttles back to idle then full power again). I would imagine the extra training went along the lines of don't fly a large passenger aircraft full of passengers at close to its stall speed 100 ft above the ground ( they actually did it a 30ft(!!) along a grass runway you've never been to before which has a large bunch of trees at the end of it. And the clear grass bit between the trees is only 1100m long. So at the reported air speed of 120kts, that's 18 seconds max. Realistically probably 12 seconds from when he levelled the plane off. The whole thing was madness. IMHO. Remember - More details = better answers Also: If you get a response it's polite to respond to it. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Its a stabilisation criteria that they are above idle at 1000ft.... No the training was 3 days worth of know your airbus fight modes and how to know which one your in and how to get into climb like an angle mode. There was also a pretty major fight system update 9 months later. These days the first airbus type rating has nearly double the amount of ground school that other type ratings have. Most of it is avionics and the FBW system. If you then go to other types in the airbus range is barely a week ground school and a couple of sessions in the sim. That's the thing the pilot said he had put the power on and nothing happened. And something only happened when he moved the levers full travel and then hit TOGA. There is a smell of the aircraft thought it was landing and went into flare mode so disregarded the power demands. It only kicked out of that mode when they hit TOGA. but by then it was too late with the spool up times. The main way to avoid this one is not to get involved with this sort of nonsense fly by's in the first place. they have been banned to my knowledge this side of the Atlantic. The AT system is seen as a major flaw in the airbus system. The power levers don't move and when your in manual they sense the position then send it to the flight controller that then demands the power from the engine. To my knowledge all FBW systems since airbus have the flight controllers sending demands to the power lever servo's which then move and then the engine controllers sense the position from there for demand. So if you over power the servo's then all the engine controller see's is the power levers in the firewall and gives you that. As i have said a few times in these threads my personal belief is that the airbus system needs requalified with modern standards as well. Its 40 years old now and quiet a few major flaws are being grandfathered and never fixed. I have been reading that Air France want a stretched version of the A220-300 and the driving force behind that is the fresh sheet FBW and cockpit which I must admit is great and the ex proper airbus pilots say is streets ahead of what they have flown ranging from A320 through to A380 and everything in-between. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] He had also disabled a lot of the protection devices, but maybe forgot about that one... As we've seen with MCAS, there can be things written deep into the code that no one really knows about or should be overridden but wasn't. but as said, maybe something was starting to happen but in the growing panic as he's looking a row of trees he didn't know were there that his brain started going faster than normal and the engines didn't keep up. So in the AB the power changes but the levers don't move?? Oh. You're probably right that something designed 40 years ago should be re-done and not just continually patched up. Remember - More details = better answers Also: If you get a response it's polite to respond to it. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] you normally put them into a gate and then they stay there until you land or decide to go manual power levers. That feature is pretty much universally hated by the Ab pilots as far as I can tell. Them moving gives you tactile feedback what the machine power state is even when you can't see them during fumes and smoke. The smoke generator in our sim seems to be some turbo powered zero viz machine. Way more effective than the one in the Q400 sim. I ended up with my mask 10cm away from DU3 and couldn't see the engine instruments last week in the sim doing that exercise. let it do an auto land and basically it looked after itself including speed reduction and the only thing we did was put the flap out and gear down after pointing it at the final approach fix and arming the approach mode. I am not saying the should be redone just a complete big picture assessment in relation to modern norms. But things that have been highlighted as issues 40 years before shouldn't be allowed to continue. There is stuff on the 737 that has been bitched about and is still a feature on the MAX after 60 years. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Quote (Way more effective than the one in the Q400 sim. I ended up with my mask 10cm away from DU3 and couldn't see the engine instruments last week in the sim doing that exercise) Sounds like a real fire... Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Good training then.... And not cheap to provide. its a CAE 7000XR sim with CAE Tropos™ 6000XR visual system. We had it on the ground and evacuated in under 10 mins. The fire and smoke checklist on all types is notorious for taking ages. Once you start it you set things up for ram air and venting as much as possible and then go through a series of tests to try and find out which system is on fire. Which is the various electrical systems then the air conditioning system. It takes about 30-40 mins to do it completely with 3 min pauses to see if the smoke decreases every time a system is isolated. We just got the ventilation going and got it on the ground. Which gave us full autoland capability because all the electrics were still online. But apparently if we had run the checklist until we had got to the 4th power system it would have cleared the smoke but then we would have been doing a manual approach with masks on which is not pleasant at the 25 min point after it started. It took 15 mins coffee break for the air blowers to clear it ready for the next exercises. All in all a productive 4 hours worth of training. We were doing the new RNP AR procedures for the new curved approaches into the likes of Salzburg. From 18 miles out flying a slalom course down to the runway. Much less stressful than doing a visual circling approach. If your interested https://safetyfirst.airbus.com/app/themes/mh_newsd... RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Quote (First paragraph) I.Executive SummaryIn April of 2019, weeks after the second of two tragic crashes of Boeing 737 MAX aircraft, U.S. Senate Committee on Commerce, Science, and Transportation staff began receiving information from whistleblowers detailing numerous concerns related to aviation safety. Commerce Committee Chairman Roger Wicker directed staff to begin an oversight investigation. The scope and breadth of the investigation quickly expanded beyond the first allegations inspired by the 737 MAX tragedies. Information received from fifty-seven whistleblowers revealed common themes among the allegations including insufficient training, improper certification, FAA management acting favorably toward operators, and management undermining of frontline inspectors. The investigation revealed that these trends were often accompanied by retaliation against those who report safety violations anda lack of effective oversight, resulting in a failed FAA safety management culture. It doesn't get any better as far as page 28 out of 102 pages. Bill -------------------- "Why not the best?" Jimmy Carter RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Just finished it. Feel quiet sorry for the grunts on the coal face, Although quiet how you would "fix" it I have no clue. Similar investigations with NASA did change things for while but then history repeated itself years later with the Shuttle. Its going to need serious amounts of money. And this is only the aircraft certification side of things. I suspect the air traffic part of the FAA has similar issues. Only silver lining is that for world certification other authorities will now be requiring compliance separately from the FAA. Quote (Senate report) VIII.Conclusion The FAA is responsible for the regulation and oversight of the U.S. aviation industry with safety as the primary goal. The Committee’s twenty month investigation incorporated information from fifty-seven whistleblowers, thousands of pages of documents, and numerous interviews. Committee investigators discovered numerous systemic deficiencies in FAA oversight. These deficiencies included ineffective or complete lack of oversight, resulting in unnecessary risk to the flying public. In many cases FAA management appears to be aware, and in some cases complicit in thwarting the very oversight they are charged with directing and supervising. In the most alarming cases, whistleblowers have warned of tragedies before they occur only to be retaliated against by managers. Unfortunately, much of what has been detailed in this report has been well known and reported on for decades. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Quote (Committee investigators discovered numerous systemic deficiencies in FAA oversight. These deficiencies included ineffective or complete lack of oversight, resulting in unnecessary risk to the flying public.) Speaks volumes... Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] ...and from the BBC, "The FAA said the Senate Commerce Committee's report contained "a number of unsubstantiated allegations", and that its review of the 737 Max had been thorough. It said it was confident that safety issues with the aircraft had been addressed." Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] The conclusion of the report is really the natural result of having one organization responsible for promotion, and regulation of an industry. Separating the organization into three entities might be appropriate, as the organizational goal could be aligned with it's function. Operations - Air Traffic Control Regulation - Any function related to enforcing or certifying Promotion - Airport Construction? The allegations are probably "unsubstantiated" due to the original documents not being appended to the report - all 13000 +/- of them, which would have created a different but equally useless comment about the presentation of supporting information. Fred RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Should have been; Quote: "The FAA said the Senate Commerce Committee's report contained "a number of unsubstantiated allegations", <s>I am so happy for the FAA that enough time has passed that they are able to forget over 300 deaths and move forward with more self serving BS.</s> The FAA has lost most of its credibility and more denial will not help to rebuild credibility. Bill -------------------- "Why not the best?" Jimmy Carter RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] They left no tern unstoned... "The head of Europe's aviation safety agency, EASA, has told the BBC he is "certain" Boeing's 737 Max is now safe to fly. Executive Director Patrick Ky said his organisation had "left no stone unturned" in its review of the aircraft and its analysis of design changes made by the manufacturer." #3 will be more interesting... Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] I personally think the only reason why the MAX will be the best is can be (but still fundamentally its a pretty horrible Frankenstein compromised design) is because of Canadian and EASA input and Boeings knowledge that in the world wide scope of things a FAA wet cloth wipe to regain approval was pretty much meaningless. As for the whole setup of the FAA and its remit. I really don't know. It's not as if EASA doesn't have its big issues. To be honest I don't know how the Canadians have it setup with funding and defined roles etc. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Nothing has changed, the world still rotates around and around. The FAA ( and all other regulatory agencies) are still owned by the major manufacturers that are supposed to be regulated, and the judges in the appeals courts are still golf and dinner partners with the executives of the industries being sued. Ah, the ecology of corruption. How sweet it is. OOPs, time to watch DWTS. "...when logic, and proportion, have fallen, sloppy dead..." Grace Slick RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] EASA certainly isn't owned by either of them. And certainly not Boeing. The FAA is screwed now for a decade at least. And so is Boeing because they have to get certified by all the other authorities the FAA opinion is basically meaningless as no aircraft will survive with just a USA region certification. FAA has two choices leave as is and basically step back and let the rest of the world do the real certification work or go in harder than the rest to prove a point. But as Boeing seems to have absolutely nothing in the pipeline for at least the next 10 years apart from the 777x which there is absolutely zero demand for and they are going to have to certify it properly with none FAA regulators they are basically screwed. I still reckon the MAX will end up with less than 2k units produced. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] It will be interesting to see if the coming Biden appointments have any impact on the FAA, either directly or indirectly. Bill -------------------- "Why not the best?" Jimmy Carter RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Ryanair's boss Michael O'Leary talks about the 737-Max. Except he didn't call it the 737 Max. He repeatedly referred to the "737 8200". Link One of the resons but not the only reason that I will pay a premium to avoid Boeing. "If it's Boeing, I'm not going!" Bill -------------------- "Why not the best?" Jimmy Carter RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] MAX is the marketing name and covers 4 or 5 type certificates. The 737-8200 is a 737-8 which is certified for 200 pax onboard which is an extra 22 compared to a normal 737-8 to be honest calling it a 737-8200 is more technically correct than calling it a straight MAX Personally I am going to call it a Frankenstein cattle truck. Most of the big regulators have now cleared it again. I haven't seen anything about china. But there is notable differences to do with checklists and the training which are different but not yet full specified. There is also requirements that in the next 1-2 years that they fit more AOA sensors or some other synthetic AoA calculation and add it into the mix for the fault logic to the AoA value to trigger MCAS. Ryanair is a bit funny it has to replace its fleet within a certain period or it goes outside its business model and incurs huge expense if any of the aircraft hit major maint inspections. It also has to stick with Boeing. It also requires inbuilt steps and there is a couple of other features it uses that nobody else does. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] A rose by any other name... Quote: MAX is the marketing name and covers 4 or 5 type certificates. Do any of those types NOT have MACS? I imagine that when a person checks his itinerary, it will list the equipment as "737-8200" rather than a 737-MAX? That is easy to confuse with a 737-800-NG. I understand that Boeing is deemphasising the MAX designation. I don't have your ready familiarization with the various types of Boeing aircraft. The safest way for me to avoid the MAX and/or MACS is to avoid carriers who fly Boeing equipment whenever I reasonably can. It's not about safety, it's about trust for Boeing and the FAA. This is interesting: Quote: There is also requirements that in the next 1-2 years that they fit more AOA sensors or some other synthetic AoA calculation That's a gamble. If a MAX goes down for any reason in the next two years it could trigger the end of Boeing in the commercial market. Quote: They left no tern unstoned... "The head of Europe's aviation safety agency, EASA, has told the BBC he is "certain" Boeing's 737 Max is now safe to fly. Executive Director Patrick Ky said his organisation had "left no stone unturned" in its review of the aircraft and its analysis of design changes made by the manufacturer." Now is "The head of Europe's aviation safety agency, EASA," meaning the MAX today, or the MAX two years down the road when the remedies have been completely implemented? While the odds that we will ever meet IRL are quite small, Alistair, the odds that we will meet sitting side by side on a MAX are non-existent. Time will tell how things will work out for the carriers who have all Boeing fleets. Bill -------------------- "Why not the best?" Jimmy Carter RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] they all have it, Its the engines which make them need it. Ryanair pax really won't care what they fly on as long as its cheap. Actually I am pretty shocking at spotting aircraft types but the MAX is pretty easy because it just looks strange and wrong with these huge engines sticking out way forward of the wing and they also have a corrugated bit on the back of the pod. They have the 737-7 737-8 and 737-9 certified already and they were grounded. The 737-10 and this ryanair special 737-8200 are not certified yet. I believe the AoA stuff will have to be implemented before the 737-10 gets its type certificate. Everything in aviation is a gamble if they weren't allowed to start delivery's again they more than likely would be finished as well. And absolutely nobody wants a Airbus monopoly even Airbus. The EASA stuff is pretty safe Norwegian are mid process in the courts to make Boeing take the ones they have back and cancel the rest and get their money back. And with the amount of flying going on just now which isn't looking like much will happen next year to improve things. Ryanair can't get theirs until the 737-8200 get a type variation certification. Nobody wants them in Europe apart from RYAnair and the only reason it wants them is to get rid of its old 737-800 NG before D check. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Quote (I understand that Boeing is deemphasising the MAX designation.) ...like putting lipstick on a pig. Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] designators for type certification are impossible to change after the type certificate is given For example the type i fly currently is called the A220 it used to be called C series. All the paperwork calls it a Bd500 and that's how its referenced in my license's. As you say changing the marketing name in this case is like putting lipstick on a pig. Especially as it just doesn't look right and unique. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Some related tidbits: In a decision dated December 21, 2020, federal Administrative Law Judge Scott R. Morris found Delta Air Lines, Inc. guilty of having used a compulsory psychiatric examination as a “weapon” against Dr. Karlene Petitt after she raised safety issues related to the airline’s flight operations. Delta selected Dr. David B. Altman as the examiner... Altman received over73,000 for his psychiatric report....
Dr. Karlene Petitt was subsequently examined by the Mayo Clinic at her own expense.

During the trial, it emerged that Delta had paid Dr Altman $73,000 to conduct the psychiatric evaluation. Ms Petitt had sought a second opinion at the world-renowned Mayo Clinic. The Mayo clinic totally debunked Altman’s diagnosis. In way of comparison, it was disclosed that Ms Petitt paid only$3,200 in medical fees. Delta Airlines was unable to explain the financial discrepancy between the two examinations.
Judge Morris quoted findings of Dr. Steinkraus of the Mayo Clinic with respect to the diagnosis of Dr. Petitt:
“This has been a puzzle for our group – the evidence does not support presence of a psychiatric diagnosis but does support an organizational/corporate effort to remove this pilot from the rolls. … years ago in the military, it was not unusual for female pilots and air crew to be the target for such an effort.”

Karma's a bitch.
After taking $73.000 from Delta Airlines to end a pilot's career......... Dr. Altman agreed to be placed on permanent inactive status as a part of a settlement of an action brought by the Illinois Department of Financial and Professional Regulation to revoke or suspend his license, or otherwise subject him to discipline. Bill -------------------- "Why not the best?" Jimmy Carter RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] So that's where the expression 'pass the mayo' came from... just jokin' the Mayo is a world class facility... unlike the new CDC. I don't think real integrity has a price... but something less than that, might... it's very sad. Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] I had a run in years ago with an employer about being sent to their approved doctor for drug testing and liver function analysis which I might add wasn't just me and also included the technicians and other pilots. The doctor was a well known butcher of an aero medical examiner and most of us avoid him even in shops. He was famous for having a dodgy ECG machine and triggering weeks of heart investigations that always concluded nothing wrong probably a dodgy lead on the initial machine. I said I would happily go to the drugs clinic in town and pay myself for the liver enzyme test. Nope that wasn't good enough it had to be him. In the end I went to my aeromedical examiner and told him about the reasons I didn't want to go near this other doctor. He then contacted the head scab lifter in the CAA and the company got told, the doctor had to get a new ECG machine. I was confirmed not to be on the wacky baccie and I could double my alcohol intake if I so wished by my normal AME. Its always worth avoiding vegan marathon running AME's. Life is less stressful when you have one that's fat, smokes and has a bottle of medicinal whisky in his bottom drawer not that he ever gave me any of it. I believe it is now in UK regulations and endorsed by the British Medical Association that they can't make you see any particular doctor. And if you state to the doctor you don't want them touching you and you are only there because the company demands it, they can be taken to task by the BMA and if they do touch you can be done for assault. I haven't heard of anyone in the UK being forced to see a company defined medic in years. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] A friend of mine was seeing a doctor for a work related condition. This was in a town so closely linked to the oil industry that any doctor who gave a diagnosis that may cost or inconvenience one of the major oil companies would be blacklisted. The doctor declared several times that the condition was not work related; And each time he then whispered forcefully; "See another doctor." Bill -------------------- "Why not the best?" Jimmy Carter RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] I did several reports for SF insurance (no name)... and they were notorious for denying claims... I would advise the policy holder that even though SF was my client, the the information in my report would essentially be the same if I were acting for my client or the policy holder. With SF, I would also advise them that they could get another engineer to provide them with a report before any changes had occurred to the damage. SF was notorious for not providing copies of their engineering reports. That the client was informed of using a different engineer was part of all my reports. Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Well that didn't take long.... Air Canada had to shut a donk down in flight and declare a pan and divert ferrying a MAX up to start work. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Donk...? Please elaborate for us uninitiated types... "Schiefgehen wird, was schiefgehen kann" - das Murphygesetz RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Donk short for donkey ie provides motive power. its not aviation to be honest. They had to shut down an engine down enroute. This isn't as bad as it sounds and is nothing to do with the work done in regards to being recertified. It more to do with sitting on the ground for getting on for 2 years. There will be multiple other in flight failures not only engines but other systems as well. Single engine won't cause any issues. Gear issues might end up with gear up landings which is a different level of media attention. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] We used to call them 'tugs', same thing? Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] This may be the first of many issues from MAX aircraft sitting unused in storage for over a year. You can perform the standard maintenance list of checks and replacements, but there will be those odd items that will fail from not being used. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] ^ Be wild if the grounding ended up being more dangerous than MCAS RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Individual failures are not much of a problem because the backup systems then get you back onto the ground. Its when you start getting two or more all at the same time it starts becoming dangerous. With the air canada aircraft it started off as a hydraulic issue.. Not a problem there is 3 systems of them... Checklist came to the point of doing a precautionary shut down of an engine. In fact as they didn't have any pax on they were going to complete the trip... Then the fuel cross feed valve wouldn't open so they ended up being only able to pull fuel from one wing. This leads very quickly to a fuel imbalance which is dangerous quiet quickly so they got it on the ground ASAP. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Is there only one cross feed valve / connection? I assume it's normally closed as both engines use similar quantities? I think there are going to be a few of these as the fleet gets back in the air due to lack of action. Remember - More details = better answers Also: If you get a response it's polite to respond to it. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] We are getting into type specific stuff and Frankenstein 1960's design. A220 has 3 methods of cross feeding. Yes you normally keep the sides separate and the engines burn about the same and it's used to spot if there maybe a fuel leak. It's not just the max fleet all fleets short and long haul have been on the ground way more than is healthy. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] From CTV News... "MIAMI -- A Boeing 737 Max departed Miami International Airport with 100 passengers aboard Tuesday for the aircraft's first U.S. commercial flight since faulty sensor readings contributed to two deadly crashes in 2019. The American Airlines flight is scheduled to land at New York's LaGuardia Airport around 1:30 p.m. Eastern, according to an airline spokeswoman. The airline gave customers the chance to change flights if they were uncomfortable on the Max." Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] Its got the fleet tech pilot FAA approved test pilot onboard. It also has a full no restrictions test pilot on board which nobody can quite work out who is paying for. So if between the two of them they can't sort it the whole program is well screwed. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] BTW a no restriction test pilot is a bit of a special beast no type rating required. I have flown with them twice..... Utter lovely blokes and utter gods flying... Chuck Yeager aviation god at handling but utterly shite at working with other people never had it. These gods can do both. When i flew with them they never touched the controls apart from the last 200ft to do the landing because they had never landed the type before. RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] From CTV news: "CALGARY -- WestJet says it plans to resume flying its fleet of 737 MAX aircraft later this month, pending approval by Transport Canada. The announcement follows comments by Transport Canada late last year that safety experts had validated the aircraft design changes and outlined requirements for Canadian carriers to bring it a step closer to resuming flights. The Boeing 737 Max aircraft has been grounded for nearly two years after technical issues led to deadly crashes in Indonesia and Ethiopia." I think that's one airline I'll avoid... Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] "Boeing admitted that two of its technical pilots deceived regulators about the safety of the Max’s MCAS stall prevention software, implicated in both of the fatal crashes." on their own, or were they 'just following orders'? Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better? -Dik RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8] The$2.5 billion is nothing compared to what it cost them while the 737-MAX was grounded, to say nothing of what the pandemic has cost them. That being said, Boeing has a market cap of over $120 billion and annual sales close to$61 billion. Yes, that will hurt the bottom line, but it's more more like a broken ankle than a broken back.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

US fines Boeing $2.5bn following fraud charges tied to 737 Max crashes Quote (The Guardian Article) The settlement includes$2.2bn in compensation to the families of the people killed in the two Max crashes and a $243m fine. What seems to have happened; Boeing was fined$243 Million and ordered to pay 2.2 Billion in compensation.
A reporter and/or editor overstated the actual fine by a factor of over 10 to 1 to add emphasis and dramatic appeal.
Is it any wonder that there is widespread distrust of the media?
Is this intentional spin or just a deficient education?

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

(OP)

Quote:

Is this intentional spin or just a deficient education?
Bear in mind that what passes for news media has been starved of cash and stripped of skilled personnel for 20 years by the internet.
While I also catch myself bemoaning the idiocy that I hear on the mainstream media, I am often reminded that I don't pay each time I read an article from the Guardian, NYT, WP etc.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

https://www.ctvnews.ca/world/indonesian-plane-fear...

“The nearly 27-year-old Boeing 737-500 was much older than Boeing's problem-plagued 737 MAX model, one of which crashed off Jakarta in late 2018, killing all 189 people aboard the Lion Air flight. Older 737 models are widely flown and do not have the system implicated in the MAX safety crisis.”

It wasn’t a max... this time.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

The older ones, it seems, appear to be handling like the Max...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

3 things you can no longer believe: test pilots, the FAA, and the media. 3 other things that almost never lie: a young kid, a total drunk, and yoga pants.

"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

thread2-477827: New FAA "system safety assessment" ?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

(OP)
Wow. I don't know exactly what to make of this, yet:

Quote (Patrick Ky, EASA, https://www.easa.europa.eu/newsroom-and-events/pre...)

"We also pushed the aircraft to its limits during flight tests, assessed the behaviour of the aircraft in failure scenarios, and could confirm that the aircraft is stable and has no tendency to pitch-up even without the MCAS."

Quote (Steve Dickson, FAA, https://theaircurrent.com/aircraft-development/mca...)

"...confirm that the aircraft is stable and has no tendency to pitch-up even without the MCAS"

Then the back-pedaling begins:

Quote (EASA spokesperson https://www.theregister.com/2020/11/25/easa_737_ma...)

"In the case of the MAX: the MCAS is necessary to meet the safety regulation and obtain the necessary safety margins. However, when it is lost (failed and inoperative), an averagely skilled and trained crew is still able to safely fly and land the airplane,"

Quote (FAA spokesperson https://theaircurrent.com/aircraft-development/mca...)

"...determined during a 20-month review that MCAS was a necessary part of the flight control system..."

www.sparweb.ca

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Dare I suspect...Politics?

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

#3, if it happens, will be a bit more difficult to explain...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

From what I have read so far, is this a reasonable scenario?
Imagine a Max that has had some system failures.
The failure are serious and either directly or indirectly lead to MCAS being turned off or inoperative.
The plane is hard to control but still flyable.
There are lights flashing and alarms ringing.
For some reason a landing is missed and the pilot executes a climbing turn on his go-around.
Without MCAS active, the flight characteristics change.
With the information overload and the "fog of war" the distracted pilot keeps steady pressure on the controls.
Even though the plane has no tendency to pitch up, it has a real ability to mislead the pilot into "pitching up" the aircraft.

I understand that Boeing identified this possibility very early on and MACS was their attempted solution.
So, if MCAS fails, it does not make the plane unstable but does introduce a change in the response to the controls that may easily lead the pilot to inadvertently pitch up and stall the plane.
Given the months of testing and the thousands of pages of reports, it may not have been hard to lose sight of the original issue.

Quote (EASA)

"We also pushed the aircraft to its limits during flight tests, assessed the behaviour of the aircraft in failure scenarios, and could confirm that the aircraft is stable and has no tendency to pitch-up even without the MCAS."
Is this ill advised as a public statement?
It seems to imply that MCAS doesn't matter and the pilots may ignore any MCAS failure.

If it's Boeing..........

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

That's careful wording. It is stable, always had been. It had been sold as 'close enough to all the other 737s that it flys the same and minimal conversion training is needed' and also sold as 'meeting regulatory specs on control feel and stability derivatives' which it didn't without MCAS.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Quote (Is this ill advised as a public statement?)

I betcha they didn't run it past their legal department... seems like a really dumb statement.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

My understanding is that it doesn't "pitch up" in the sense that you need to apply negative force to stop it going vertical, but that the control forces reduce as you hit high AoA.

This is contrary to the regulations.

The reason is to prevent stall in a panic mode of operation when the pilot keeps pulling back on the controls.

Good pilots in relatively easy conditions cab catch this. But some may not. Hence MCAS was born.

Happy to be corrected.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

(OP)
While I can't find the original source or how the details on it were created, it matches the problem as described by Boeing and repeated oh-so-often in the media as it relates to pitch forces. There are popular graphics still being republished in the press that get this wrong.

The chart plots "Cm,CG" which in the flight-control context means "Coefficient of pitching moment about the Center of Gravity".
It relates to the proportional force on the control column that you need to push/pull to maintain a steady angle of attack, with all other conditions in equilibrium (enough power to maintain constant altitude and speed at the same time).
The desired response of the aircraft is to resist an input force on the control column with a reaction that returns the aircraft to the stable condition, which is called "trim" in aviation. When the reaction is the opposite of the action, the "feedback is negative" so to speak, and that makes the result of the force balance negative. That's why the line passes into the negative region of the curve.

What the regulatory officials said - in these terms - is that "the Cm curve does not cross over the X-axis". If it did, that would be unstable, which means a pull backward on the controls would lead to the nose constantly going up without self-correcting. So what Patrick Ky and Steve Dickson said was that it doesn't go run away from you. They are probably aware that the popular press has exaggerated this often. The regulators probably felt that once they had experienced the control responses for themselves, they could make a statement to counteract the mistakes made by the press.

The spokespeople later had to clarify, because it seemed to undermine the need for MCAS at all. In closer detail, there isn't an instability being addressed by MCAS. However there is the tendency of the restoring force to level off at high angle of attack. That's the solid blue line in the chart below. For the forces to seem relatively constant over a range of angle of attack, even though they are pushing against you as you pull up, they aren't giving you the "feel" of nose pitch up because the force doesn't increase much. The restoring force should increase as you pull more and more away from the trimmed condition. This takes us down to a finer level of subtlety. I would like to know if it is really perceptible by a pilot when MCAS is off, or just measurable with flight test instruments.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

A much better technical explanation. Really is only that last little uptick that looks odd.

So both statements are true but not many will actually understand the difference.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

From that uptick took up at the at the horizontal line.
That is the stall point.

Do I read that graph correctly Spar?
One cycle of MCAS will bring handling characteristics into regulatory compliance out to the stall point?
From that graph, it would seem as if one cycle of MCAS would be all that was ever needed to counteract the uplift.
From the graph it would seem as if any further increase in AoA after one action of MCAS would be due to reasons other than nacelle uplift.

Are there other factors that are not apparent from the graph?

Suppose that these few lines of code had been added to the program.

Is angel of attack past the set point;
If no, no action.
If yes, engage MCAS.
Repeat;
Is angel of attack past the set point;
If no, no action;
If MCAS flag is set, No action;
If yes, engage MCAS;
Set MCAS flag;
Repeat;

Failure modes:
MCAS fails to activate when it is required.

Quote (EASA)

"We also pushed the aircraft to its limits during flight tests, assessed the behaviour of the aircraft in failure scenarios, and could confirm that the aircraft is stable and has no tendency to pitch-up even without the MCAS."

MCAS activates when it is not required.
Won't happen.

This could also be implemented with a hardware solution, so that the trim is adjusted by other means than turning the jack screw.
A hardware solution would avoid the possibility of a MCAS malfunction leading to a trim runaway.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

We're heeerrrrreeeeee:
Canada said on Monday it will lift a near two-year flight ban on Boeing's 737 Max on Jan. 20, joining other countries like the United States that have brought the aircraft back following two fatal crashes involving the model.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

(OP)

Quote (LittleInch)

So both statements are true but not many will actually understand the difference.

Sadly so, and even I've fallen victim to the verbal short-hand of mistaking a measured force gradient for the force itself in various conversations. It's like hearing the same lie enough times to believe it. In this case, not a lie, but a mistake misspoken enough times that it confuses the real details. Heck, I should also repeat that I still haven't found the origin of the chart I'm using as an illustration of my argument. As such, there could be other errors or oversimplifications in it that I'm not noticing because I'm not paying attention to anything but the trend on it. So Waross's follow-up questions are no surprise. Actually, the point where the chart passes the point of zero Cm, over 5 degrees, is a bit high. The plane would not have that much nose-up attitude unless it's at max gross weight. Although, on second thought, max GW is a common point of reference for aerodynamic parameters, so maybe not so strange. I think the stuff on that chart is square with reality, I just can't prove it.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Quote (waross)

This could also be implemented with a hardware solution, so that the trim is adjusted by other means than turning the jack screw.
A hardware solution would avoid the possibility of a MCAS malfunction leading to a trim runaway.

Something close to this was the previous design and why there are two switches to turn off the trim in the cockpit. One motor drive was the STS (Speed Trim System ) and the other was the pilot controlled trim.  If it was still this way then yes, MCAS and STS could share a trim input to the stabilizer and importantly, bet cut off and the pilots would still have powered control of the stabilizer.[/edit] I forget why there was no way to use the old design in the new application.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

more news...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Hi moon161.
By hardware solution I visualized a part of the linkage that could be extended or retracted by an actuator.
If you need MCAS, the linkage is extended.
If you don't need MACS the linkage is retracted.
Any failure would be limited to either one MCAS operation or no MCAS operation.
The graph shows that one operation restores the control pressure to the stall point.
You should never need more than one action to counteract upthrust.
There are many ways that this could be implemented somewhere in the stab trim linkage.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Quote (waaross)

You should never need more than one action to counteract upthrust.
I don't know. Maybe it would be proportional to the amount the throttles are moved? Regardless, if I interpreted everything right, then the decision to give MCAS full authority over the elevator (or is it stabilizer?)control was obviously ill-conceived. I think in the end it was really functioning as an anti-stall device, not really associated with movement of the throttle.

The more you know, the more you know you don't know.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Quote (dik)

more news...

From the article--
His report draws on material from the official investigations. It claims that both of the crashed aircraft suffered from - what he believes - were production defects, almost from the moment they entered service.

That's an interesting article but if something has a production defect, wouldn't it be there on day one?

The more you know, the more you know you don't know.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I don't see how some kind of linkage fix would make it any safer compared to limiting MCAS authority. To me, that actually sounds like a bad idea.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Quote (WAROSS)

Hi moon161.
By hardware solution I visualized a part of the linkage that could be extended or retracted by an actuator.
If you need MCAS, the linkage is extended.
If you don't need MACS the linkage is retracted.
Any failure would be limited to either one MCAS operation or no MCAS operation.
The graph shows that one operation restores the control pressure to the stall point.
You should never need more than one action to counteract upthrust.
There are many ways that this could be implemented somewhere in the stab trim linkage.

Oh hey I like that idea, a series arrangement instead of parallel. This could have safety designed in by limiting the MCAS design stroke to ± something small and the manual trim to the full range of motion required for flying trim.

And mom just called me Andy

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

The KISS principle, Lionel.
How much software and hardware has it taken to make MCAS safer?
There are a number of possible solutions to an adjustable link that will only move between two positions, and will be reliably restrained between those positions in the event of an actuator failure.
Unfortunately Boeing management never got out of the rabbit hole of a "cheap" software solution.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

A mechanism added into the stabilizer screw still sounds like a very bad idea and besides it would most likely break any possibility of the variant ever being certified to fly.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

They could have told the pilots about it and given them a button / switch to disarm it if it ever went wrong.

Now that sounds like it was a good plan that never happened. Possibly linked to this non SIM training rubbish which should have been laughed out of anyones thought pattern. You only have to look at the two cockpits to realise you were looking at something very different never mind this MCAS issue. If there is a lesson learnt anywhere then that really should be it - these really were two different airplanes and trying to pretend it wasn't for the sake of \$1M per plane to SWA has proved to be a very false economy.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I may be wrong but I am under the impression that the 737 at one time had two drive mechanisms on the stab-trim jack screw.
A second drive on the bottom of the jack screw could easily have its movement restricted enough to just counteract the lessening control force.
Just one of a number of possible solutions.
Don't fight the problem.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

The other thing I don't get about MCAS's design is why the "single activation" performance is OK. Why not tune a PID to more closely approximate the desired performance curve (linear up to stall)? That's totally separate from the safety issues, just it seems odd to me to have it working in large discrete steps when an analog circuit with appropriate feedback could do a potentially better job. I expect the answer is that new active circuitry would change the type rating, they needed something that could run on the existing computers with the existing inputs.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Bill, you do understand that MCAS just moves the stabilizer once when it activates? It doesn't move it back later. The processing capabilities of the controls sound like they are too limited to have any such extra smarts added to them. I haven't seen any proof there was once 2 drive motors on the jack screw, but even if you put 2 motors on the screw both would have to be able to rotate with the screw through the full range of travel so the 2nd one could not be travel limited. After MCAS moved the screw, the other motor would need the ability to move it back.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Quote:

Bill, you do understand that MCAS just moves the stabilizer once when it activates? It doesn't move it back later.
That sounds like another engineering failure.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

The idea was that once your AoA went below the limit for activation, it promptly de-activated and moved the stab the other way back to where it was before.

And don't forget the 737s have a Speed trim system which kicks in at different speeds etc to trim the aircraft automatically as thrust and AoA change. Again a set of limits apply as to when and how much it trims the stab. The A/P does the same thing. So it wasn't a surprise to the pilots when the trim wheel keeps spinning around all on its own.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

If I recall correctly, on the original 737s I think there were two motors on the jack screw - one commanded by the A/P etc and one by the pilot via the thumb switches. Hence you could lose or disable one set but use the other. But it was a lot of extra weight and the NG reduced this to one motor but two switches in the cockpit to disable the A/P / STS input. Then the Max just made it two switches in series. So all or nothing / manual. In the mean time they had also reduced the size of the manual trim wheel because the bigger one on the earlier version got in the way of something. And made the stab bigger so it became harder to trim it manually at high speeds.

SO as usual what seems a small individual change which on its own is Ok finally all came together in a bad way. That's the problem with keeping the same type certification over time. It all starts to add up and sometimes that number goes negative.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

More news...

The 737 Max will fly again in Europe, after regulators gave Boeing’s BA, -2.82% bestselling aircraft the all-clear for takeoff following nearly two years on the tarmac.

The plane was grounded by the European Union Aviation Safety Agency, or EASA, in March 2019 after two deadly crashes claimed 346 lives.

Approval from the EASA came with the mandate of a package of software upgrades, electrical work, maintenance checks, operations manual updates, and crew training.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Quote (LittleInch)

That's the problem with keeping the same type certification over time. It all starts to add up and sometimes that number goes negative.

That wouldn't be a problem if the rule were that the total set of changes has to be evaluated against the original model, and that any newly approved versions must satisfy all current requirements at the time of their approval (rather than the requirements from the time of the original model's approval). If it changes too much to behave like the original, it shouldn't be part of the same type certificate. If the rules are stricter than they originally were, it should comply with the new rules (and keep the original behavior as closely as possible). If it can't do both, it should get a new type certificate.

Of course that would be expensive, so it won't happen.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

That's likely the way it should happen if it weren't mired in politics...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I would caution against stepping onto that slippery slope. Had the MAX required a new type cert, it would have likely doubled or tripled its certification process time. That would make it less likely for companies to create new planes and possible cause stagnation and less innovation. This would result in older fleets and fewer secondary market planes for startup airlines to buy, and possibly, what they could buy would be too old to be practical, so possibly less over competition in the airliner industry.

California's remodeling industry has some parallels; the California remodel pegs tax assessments against the ability to claim that a house has not been so substantially rebuilt that it should assessed as a new house. So, the law is written such that a "California remodel" is considered to be the original house, and tax base, if even a single wall of the original house remains; I was on the verge of making an offer on a house that was originally a 1200-sf ranch-style, that was remodeled into a 5700-sf mansion. There were eventually too many other negatives to move on the deal, so we bought something else. So that's one extreme, but the other extreme would be if someone owned a house for 30 yr and decided to add, say, a single room, and the house required compliance to ADA, full tax reassessment etc., which would require double or triple the cost of single-room addition, in addition to increasing property tax by 7x. That would stifle remodeling of any kind, to avoid that shock to owners that possibly couldn't afford to sustain a 7x property tax payment in perpetuity.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Quote:

any newly approved versions must satisfy all current requirements at the time of their approval

I'm thinking that would kill the ability to grandfather any changes on any plane designed more than a few years ago.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

...maybe not a bad idea, Lionel.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Quote (ir stuff)

California's remodeling industry has some parallels; the California remodel pegs tax assessments against the ability to claim that a house has not been so substantially rebuilt that it should assessed as a new house. So, the law is written such that a "California remodel" is considered to be the original house, and tax base, if even a single wall of the original house remains;

I've seen a couple buildings in NY state that were either demolished to a framed door that was enclosed by new construction, or the old building was enclosed by a new one, then demolished, to get around a moratorium on new builds in the area.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

...unintended consequences

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Common in cottage country in Ontario... get the building inspector to agree that you can construct to the same footprint... then teardown and rebuild... there have been a few instances where the person has demolished the structure only to be prevented for new construction.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Didn't mean to completely derail the discussion. My point was that asking for a new type cert for every change would be prohibitive and result in much more expensive and rarer occurrences of new planes. That's not particularly desirable. Obviously, the California remodel isn't suitable either.

I'll pull an analogy from a file synchronization program that refuses to automatically synchronize if more that 30% of the files have changed; so we could require a new type cert if the plane changes by more than 20%. How to define the 20% would be the challenge, though; although one can imagine if there were more than 20% new or modified drawings, that would require a new type cert.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

It'd be a terrible idea, unless you wanted to very significantly reduce the number of planes in the sky.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

There has to be a mechanism to allow for 'minor' revisions and a complete 'rebuild'. What they have now is unworkable from a safety standard.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Yep. The current system can't distinguish when a thorough re-evaluation of the whole system is needed vs when a change doesn't cause substantial differences to the overall behavior. I don't want silicon valley style "move fast and break things" "innovation" applied to aircraft. I also don't want all progress to stop.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I still can't believe the manual trim wheels.
As I understand it, you have to have manual trim but manual trim doesn't have to work.
That was my understanding of the answer given when last I asked about the manual trim issue.
In the event of a runaway trim, that cannot be corrected by electrical means, the manual wheels may not be able to be used.
Why not?
There is no regulation that says it has to work?
The organization that sets the rules cannot address the issue because they haven't written a rule?
The FAA may have more serious organizational problems than grandfathering.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Beyond just satisfying a series of individual regulations, oughtn't there be a system level design assessment by the regulatory body? Along the lines of an engineering student competition where the entrants present their design to the judges, explain the design philosophy especially as it departs from current established practice or the grandfathered design, and provide a comprehensive theory of operation, including system DFMEA? And the regulator would of course have the opportunity to ask questions and probe into areas not clearly explained, or showing potential for serious failure modes not addressed in the DFMEA, or other possible lack of robustness. If such an oversight is already in place, why didn't it work? I guess that would be due to malfeasance and/or negligence on both sides.

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

That is all part and parcel to the political parties' desires to "trim the fat" from government agencies, which used to have scads of "subject matter experts" that could have done the job, but it was decided to forego that, and use industry SMEs instead, but the only available industry SMEs were those on the payroll of Boeing itself, particularly since we're also talking about opening the kimono and revealing ostensible proprietary information.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! https://www.youtube.com/watch?v=BKorP55Aqvg
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers Entire Forum list http://www.eng-tips.com/forumlist.cfm

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

as a follow up to the above comment on FAA SME's, it was reported that the FAA had 2 senior SME's leave the FAA during the evaluation of the 737 Max. It would be of interest to determine why they had left and where they went; if they were hired by a client of Boeing for a much higher salary then that would suggest Boeing complicity in preventing an FAA expert review of the max.

"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

waross,

I agree and almost - my understanding was that there were no specified limits on the force required to move the manual trim lever / wheel. It might have been possible to move it if built like Arnie, but not a small pilot / female.

As I understand it the force required is quite variable and gets much higher as speed increases - a kind of squared velocity effect.

Hence why it might be feasible when going slowly, but not at the speed the Ethiopian pilots were going at.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

We are on the same page, LittleInch.
As well, the further out of trim, the greater the force required.
I'm open for correction here, but I understand that the further from the Center of Gravity the engines are, the more need there is for speed trim, and those Leap engines are a long way from the center of gravity.
The placement of the engines may also play a part in the amount of travel of the stabilizers and the forces due to out of trim conditions.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

On the scope of grandfathering.

The 737 MAx is a bit special due to the last version NG. It was certified just before the new grandfathering regulations came into force. If had been certified a year later then I suspect the max would be a completely different beast due to changes that would have been enforced on the NG.

But because the NG managed to get through then they had a window to grandfather through stuff which wouldn't be allowed if it had gone 500 directly to the MAX. But because it had been allowed in the NG and hadn't been changed NG to MAX then they didn't have to recertify it.

There is missing a big picture limitation on grandfathering from the initial full certification. Nobody wants to stop single step or dual step increments. But when it gets to 60 years worth of incremental reg's being avoided and your on the 7th iteration you need a big picture review how its all working together.

Something is happening though.

The 777x has been put back and the 737-10 is also put back. I believe they will be adding more AoA sensors to the 10 then retrofitting them to the 7,8,9

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

A lecture to the Royal Aeronautical Society on the 737 Max and history.

https://youtu.be/JApoVC6iIIE

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Just watched it twice and utterly excellent. Chris has no formal engineering training. Any of the acronyms used feel free to ask what they mean its even heavy going for me translating them while listening to it.

I have never flown with him but mates that have say he is an extremely knowledgably high IQ person.

So you know the this is the official controlling body for Aero engineers in the UK. I used to hold letters after my name off them. They are the ones that issue CEng status.

Edit to add I don't know how things can move forward from this. The regulator is defective which means the rest of it is nonsense.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I've only seen 15 minutes so far.
A reflection or more appropriate a memory came to mind.
My dear beloved CH always said that a machine is never better than its mechanical design or its tolerances.
Which is also my conviction and experience, that is...
It is not possible to program away "bad mechanics" or tolerances.
Now I do not say that the plane of origin was bad.
But the mechanical changes they made had a negative effect from a control perspective and then they tried to "program" it away.
Never a good idea.
A machine is never better than its mechanics.

Mixing manual and automatic control is as I see it from a "machine" perspective not possible.
I do not know how many times I have tried to explain to technicians and production people that I can not program away the problems they have when they operate the machines manually.
It is impossible to predict in the program when someone will do something to be able to program away the consequences.

Like I said, I've only seen 15 minutes so I hope this ends better than it started.

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Quote (I've only seen 15 minutes so I hope this ends better than it started.)

It explained a lot of things I only thought I understood... overall it was good.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I enjoyed the history of the MAX.
The presentation was quietly pro Boeing.

Quote:

All design flaws rectified.
But there were a few issues that were not mentioned.
Apparently Boeing did not consider re-positioning the engines.
Fix the problem, don't cover up the symptoms.

There is no question that the MAX is the most scrutinized aircraft in history.
It is probably the most compliant aircraft in history.
But;
Is it the safest aircraft?
I understand that the manual trim system is still unusable when it is most needed.
Apparently, there is no requirement for a manual trim system to be actually usable.
It appears that Boeing's and the regulator's mindset is more CYA and what can we get away with cheaper than it is on safety.
At this point, another crash due to design flaws may be the end of Boeing's presence in commercial aviation.
That's a lot to bet on a manual trim system that may be unusable when needed the most.

Quote:

Unfortunately, serious questions remain as to whether Boeing and the FAA have fully and correctly learned the lessons from the MAX failures.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Quote (dik)

It explained a lot of things I only thought I understood... overall it was good.

I didn't refer to the actual online lecture.
But it was such an echo, so at first I thought it was something wrong with my headset.

It was comment to how the Boing and FAA has handled this.

QRH
MMEL
FCOM
I got most of to, it's just this abbreviations that makes it a little fuzzy..
I probably could make a good guess but then Alister would go on me so I better not

I am not shore how many different types (as in different construction) of AoA devices there are or if they all build on the same principle.
Seems hard to make software one, whit what I know about the function.

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

QRH: is quick reference handbook. Basically its a load of checklists which tell you how to deal with various failures and situations. On the max its a paper book where you have to memorise the important ones that need a quick response and loads of others which you can look up then read and do. The modern system is a thing called ECIAS which combines the system which alerts you to a problem with the procedures list of what your meant to do and then monitors the aircraft settings so you don't change the configuration from what's required.

MMEL: Master minimum equipment list. Its the defects you can carry on a flight with various conditions and changes to the procedures. It also gives a time span to get them fixed. which can range from 1 flight to get you back to maint base no pax eg gear locked down limited to 15000 ft speed 240knts and no icing conditions, through to 120 days for things that are really not important like the logo light on the tail. The next document up which we use daily is called the MEL but it can only be more restrictive than the MMEL.

FCOM: I think it has French origins but we use it to mean Flight Crew Operating Manual. Usually comes in 2 parts, one which details the systems and the Part2 which tells you the procedures. They are both pretty meaty with about 3000 pages in each one.

AOA are either vanes that move with airflow or things that are called smart probes which use pressure differences along a pitot tube to work out the AoA. There are other synthetic methods but : don't know much about them because I have never flown anything fitted with them. Q400 had 2 vane AoA's on it. The A220 has 6 smart probes.

Can you reword the question please about feel different pressure. In aviation they use the word feel and pressure quite a bit across numerous systems and its has a different context depending on the system being talked about.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Can I help?
This is the one that I was wondering about?

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Quote (It was comment to how the Boing and FAA has handled this.)

That's the sound they make when they hit!

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Feel diff pressure

Its to do with the hydraulic systems and the force feel system on the elevators. There is power assist on the controls, the feel system applies a force onto the controls which varies with the amount of input aerodynamic loads airspeed
and a few other things. So the more you pull the more more force you feel. Faster your going the more force there is for a given deflection.

The feel computer can use either A or B hydraulic system and when there is a big split of pressure between the two sources it illuminates that light. Quiet how that would be triggered by a faulty AoA sensor i really don't know. I suspect its unrelated.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Its a known issue which hasn't been fixed since the feel system was originally certified back in the 60's. But they never bothered fixing it. There is actually a surprising number of "funny's" that have have never been fixed.

https://www.satcom.guru/2018/11/stabilizer-trim.ht...

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

(Edit) I wrote this before you posted the last link, I had not submited it, became distracted since resewing a phone call.

I assume that this is done to give you the same feeling as if you where flying an all mechanical system.
Without this feedback system you would not have any sense of the forces that are acting on the plane correct?

I also think that this feedback pressure for the the force feel is a calculated value.
Because you can not get a force feel value back from the hydraulic system that controls the angel of the elevators since it is kept in the same position as you want it regardless of the speed air pressure that it is exposed to.

If the force feel is a calculated value, one way of doing it is to take AoA value and combine it with speed and the angel of the elevator, and from this tree calculate the expected force on the elevator that you would have felt, if it was a all mechanical system.
And then the calculated force is feed back to a the controls.

And if it was as in the first crash that one AoA was wrongly calibrated.
The calculated force on the left (A) and right (B) side would have been different.
When compared that would have lit the FEEL DIFF PRESS lamp..
As explained in the video, the left side AoA was connected to computer 1 and right side AOA was connected to computer 2.

I am not saying that this is how it is done, it's just my theory.

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Sounds reasonable.

Just leave it.

This is very type specific stuff. The other big issue which nobody seems to want to deal with is the Christmas tree lights spread around the cockpit which they had to deal with. As that link shows there is a load of things which will light up but it's not obvious that they relate to any one system failure.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Is this the section of the very long linked document that we are looking for?.
It is actually the last line of the previous topic.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I was just reading that section..
Haven't found a connection to AoA sensors yet only pitot pressure..
It's a lot to read through.

BR A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

There is a link from the stall system to the electronic feel shift module EFSM.

I can only presume that when the stall system is triggered by the dodgy AoA reading it does something to the feel system.

This is pure speculation though.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Well as I sad it is a lot to go through.
And it's seems that the link is going through some development faces as well.
Is it so ?
I am just skimming through right now.
This might take some time at least for me to evaluate, since all systems seems to have one or more parts together.

Have a lot of the same things going on at work right now, and it's just chaos.

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Your link says this about the force when a stall is thought to be occurring. This says it increase the"feel" by a factor of four....

The elevator feel computer has a feature where it creates four times the forces to pull back on the column than normal.

When the stall identification function is trimming stabilizer nose down...

(with the thinking that this is a stall recover, believing AOA perhaps erroneously, and assuming that engine thrust is going to increase rapidly),

...column feel forces are designed to fight the pilot pulling back on the stick (to encourage the nose dropping), and also to avoid the pilot tripping the column stabilizer override switch if they pull it back far enough.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Sound sensible LI

So not only did the pilots have it out of trim when the MCAS triggered but they also had x4 feel fighting them pulling the stick back.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I think I have figured out why the FEEL DIFF PRESS lamp was lit..
Haven't found a connection to the AoA yet, have just finished the hydraulic system..
I might finish it to morrow.
Want to look over it one more time.

Best Regards A

PS. It's a crisis at work so I have to sleep now.
2 technicians who have had 4 months to do a procurement on a motor drive and new servos and I have said since New Year that it will not work and yesterday when they where suppose to sign the contract and the supplier got all my questions they also realized that it would not work.
So now I have 24 hours to fix the documentation and what is needed so they can adjust the contract.

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I wouldn't worry about it Ana. There are so many interconnections between the various systems. I think littleinch has it right.

The problem with all these interconnections is working out what the primary cause is. Because the 737 doesn't have a centralised warning and caution system the pilots have to go searching round to spot all the different indication lights and gauges then take what they see and then work out what the problem is then find the right checklist which may have multiple branches depending what lights are showing.

Modern ECIAS system when something triggers it automatically pulls all the relevant checklists up onto one screen and then on the A220 gives you a white arrow next to the one it suggests as the most important. And it does change depending on your altitude and a few other things.

In my experience you can get 7-8 checklists coming up and then after you have run the suggested checklist then there are 1 or 2 left to run but they are procedure checklist for the new config. Then it automatically changes your normal checklists for any restrictions that are now imposed. If you inadvertently change the configuration away from what's required it then throws the checklist back up and highlights what the required configuration is. Its relatively easy to keep two people monitoring the aircraft while your running the checklists and most of them take seconds. The old paper QRH's you first of all had to get your hands on it then work out what's wrong and then find the right card and start to run it. Once finished you then had to go back and see if there was anything else which required a checklist. If you forget any restrictions or change configuration then human error is the conclusion in the accident report. This can take 10's of minuets.

Realistically the NG should have had this system but they got away with not having it by a margin of a few months. And because the NG doesn't have it then the MAX didn't have it. So its stuck with the same system as the original 1960's 737.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Quote (Alistair)

I wouldn't worry about it Ana.
I do not worry
It's as with most things a problem a mystery that has stuck in my head.
I need to figure it out, before I can let it go.
Gives me something to do while I wait for the corona pandemic to ease.
I might have bought a jigsaw puzzle instead.
Is everything OK with you?
When you sade that you where home alone (quarantine) does that mean that you are not allowed to see your family either ?

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I can see them, I keep them on the farm where its less restrictive living in the city.. But they all came down with covid last week one of the kids brought it home from school. I tested negative everyone else positive 5 adults and 4 children in our extended family bubble.

When I go to work though I have to cross a border and then its full quarantine for the period of work for 2 weeks. I am actually disappointed I didn't test positive that would have given me a free pass for the next 3-6 months from quarantine and testing....

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I am sorry to hear that I hope they all will get well soon.
That must be hard on you not seeing your family.
I have at least chosen my on quarantine.
C.H the only one I would like to see isn't here anymore so it makes no difference to me.
If you get bored you can always come and discuss some traveling at the hobby forum.
I am almost always on line.

Best Regards and be well Anna

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Its more the constant changing of rules and procedures by the Government and finding ways to jump through the hoop's to comply with them. If you mess it up its 3000 euro fine.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Inherent in both the Flight Control Computer (FCC) and Stall Management Yaw Damper (SMYD) is the angle of attack sensor, or AOA sensor.
The AOA sensor data is used to determine airplane pitch attitude to set the stall warnings and to calculate performance data.
Amongst the many analog interfaces, the Stall Management Yaw Damper outputs discretes for stick shaker and to activate the elevator feel shift module.
Each Stall Management Yaw Damper activates its on-side stick shaker motor.
When airspeed is close to a stall, the Stall Management Yaw Dampers do the Elevator Feel Shift (ELF) function by operating the Elevator Feel Shift Module EFSM which provides 850 psi (58 bar) hydraulic system A pressure to the elevator feel computer and the dual feel actuator.
This causes the elevator feel force in the feel and centering unit to increase and to counteract or resist elevator up movement at the control column.
Activation of the Elevator Feel Shift Module occurs at an AoA of 8 to 11 degrees depending on flap position.
There are no other flight deck indications when this system operates.

And the reason why the FEEL DIFF PRESS lights up is that since it is only hydraulic system A that provides pressure to the elevator feel shift module and it also provides pressure to only one side (channel) of the elevator feel computer when the SMYD dual coil solenoid valve is turned on the pressure difference between channel A and B in the EFC:n becomes more then 25 bars and then the the FEEL DIFF PRESS lights up after 30 sec.

And one AoA was calibrated wrongly 21 degress the first crash.
And it is enough that one stick shaker motor activates for this to happen.. as I see it..

The only thing I am not shore of, is if both SMYD:s are always turned on or if it is only the one on the side witch is the captain "designated driver" ??

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

From Boeings standard with the rest of the design I suspect it will be only one in the loop with one in back up ready to take over mode. Or one does each side.

But as usual nothing to indicate its fired.... apart from a cryptic hydraulic pressure differential light. And its on the flight control panel which is on the ceiling right at the very back of the overhead panel behind the pilots heads and out of view.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

No there is two one for each side left Aoa and SMYD 1 for captain and right AoA and SMYD 2 for O.P ??
What's the other side called ?
I an not shore if both is active all the time.
As fast as one of the stick shakers starts left or right regardless of reason both control columns are "looked" and the light goes on and all the other "Christmas tree lights" as well depending on the problem.
AISI..

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Sounds about right but there is usually some logic which has 1 side the master and the other the backup or they run them solo and each side looks after itself with neither side backed up. Depends on the design philosophy. British aerospace always used to run them solo don't have a clue what Boeing does.

Just so you have a reference this is the max cockpit

And this is the flight control panel. Which is located in the top left of the photo above most of it out of shot I think.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

you think that's bad here is the CB panel. The ones with the collars on them are the ones that need to be pulled in various checklists. I don't have clue where the stick shaker CB will be. But with all of them someone will have to get out of their seat to pull it.

Modern aircraft designs have electronic thermal circuit breakers which automatically alert you that they have tripped and tell you which system they are on and which checklist to run and what you loose all through the 5th screen in the cockpit.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Well I know that new people that come and work at the press shop feels like that when they are going to learn how to drive the presses but there isn't even 1/4 as many buttons on the presses ..

I cant really see anything on the pictures that looks like the SMYD.
I found a reference that says it is located in the E&E bay on the E3-2 shelf.
E&E bay ???
It seems it does not always look the same.

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

thing is some of those switch's on Boeings come down to turn on and some go up...

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Sounds logical and consistent
Have you ever flown one?

BR A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Not a max or other flavour in the actual aircraft but Boeing sims are probably the most common sims available, so there is usually open slots for low level course such as multi crew cooperation.

Because they are available when company's for other types are recruiting they tend to use them for doing check flights to makes sure you can fly a procedure and straight and level. So I have been in both a 737 classic and NG sim a few times.

Also sometimes you do someone a favour by being a the second pilot on a course that needs it done quickly but doesn't have a sim partner. But these course are not type specific so you don't need to know teh nitty gritty of the type as you don't go near the emergency procedures apart from knowing how to secure the engine after a failure.

What is noticeable though flying with ex 737 pilots is the amount of rule of thumb they use and additional procedures which they think everyone does on every type and are good airmanship. But in reality are just 737 specific. They absolutely poo themselves when you drop a wing while landing to control side slip in a xwind landing. Its because the 737 has a very small ground clearance from the bottom of the engine so they are petrified they are going to scrape a pod. BUt they try and apply the 737 limitation to other types which you can do 10 deg and then the machine starts bitching "bank angle" and even then you won't scrape the engine pods until 16 deg bank. But the ex 737 pilots will start screaming if you get anywhere near 5 deg.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Sounds a lot like the Pixar short movie Lifted
I think it is hilarious.

Putting an even bigger motor on the 737 does not seems like a good idea then?

BR A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

The max is a Frankstien collection of 1960's and modern design. They have changed absolutely nothing over the years unless it was regulated that they had to. There is issues that have been running since the first one left the hanger and they are still present in the MAX.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I was trying to find out if there was any technical changes made to the Max8 before it was approved for flight again, but it's like looking for a needle in a haystack
Someone who knows?
And was the function to increase and to counteract or resist elevator up movement at the control column when airspeed is close to a stall, via SMYD > ELF > EFSM something that came with the MCAS or it is an old function that all 737:s have?

And some "stupid" questions"
I so a video with some captain referring to the 737 Max8 as a she..
Is all airplanes female?
And if so is it because it is a "ship", since all boats also is "female"?
And I am not shore I would like to why.. if that is the case..

And do all commercial aircrafts have the captains seat on the right side?
Are air traffic "left traffic" ?
Is it due to the Romans or the Vikings?
Since most people are right handed it would be more natural to be sited to left since most controls are in the middle..

And finally..
I guess this one is mostly to Alistair, the guy in the video do you know of him and is he Swedish?
Am quite shore he must be the way he speaks English.
Since cockpit door is always looked now a days I guess the knowledge conveyed in the video want come in handy but it was a bit educational anyways..

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Anna,

Go back in this post to the 18th nov and there are the links to the faa site where its all listed.

The force thing I would think was a standard 737 thing.

Planes and ships seem to be female. Don't know why.

Pretty sure Captain sits on the left, First Officer/ Co pilot on the right.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

LittleInch
Thanks I will have a look at it.

Well the Feel Force Computer probable was, it was needed after making elevators mechanical.
But I not shore about this extra force prohibiting the pilots to counteract the systems when the stall warning comes if that is a old function on that plane or on any other plane?

Pretty sure Captain sits on the left, First Officer/ Co pilot on the right.
Me to but I just wonder why?
That is the same in cars when driving on the wrong side of the road.
Why that is so, in commercial aircrafts I do not know.
In small planes it is usually on the "right" right side.

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Fixed wing, Captain sits in the left-hand seat. Rotary, it's the other way round. No idea why.

A.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Where was the rotary generally developed? US or Europe/Asia?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

thanks LI... great explanation...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Fixed wing its due to the rules of the road and collision avoidance. Which came from the maritime world.

So the pilot always has the aircraft they are manoeuvring to avoid in view if sitting in the left seat. Don't have a clue in rotary but that article I can see the logic with having a hand that can come off but keep one hand on the cyclic.

In English speaking culture most things in aviation are taken from Maritime to do with naming and ships are always she. I think German its masculine and Russian they always call aircraft he as well.

The UK driving on the left side dates back to Napoleonic times and which hand your sword is in before that and jousting, I was told many years ago in school.

And yes Mentor pilot in that youtube is a Swedish pilot. I have chatted with him online but don't know him. He knows his stuff and has a good way of delivering information.

Back to Engineering though the feel system I believe is common through 737-300 through to the MAX it was one of the systems that missed getting reworked when they went to the NG and beat the new grandfathering rules. They more than likely wanted to use it to do the function of the MCAS. But if they touched it then they would open Pandora's box of it and the stall system which would have triggered additional training requirement and lengthy certification possible completely replacing the stall system.

There is something funny with the stall system with both the FAA and Boeing. They have always been extremely adverse to letting the pilots be able to cancel it. I suspect the original design team basically made it so that its impossible to rework the current system to the modern standards due to this clash of opinion. I am expecting that pulling the CB on the stick shaker like the Canadians and EASA have mandated is going to have a knock on effect which again is not documented. I believe the 737-10 will have some changes which should be retrofitted to the others but what I really don't know. And I suspect there will be huge arguments about them and lengthy delays certifying it.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Thanks Alistair..

What is the modern standards for stall systems?
And did you mean that the "locking" of the column at a stall was original on all 737?

Why I am asking is because the elevator feel computer EFC and the dual feel actuator seems to be able to do there job as they are suppose to, in a good way, which has nothing to do with any "safety", as longs as you do not mix it up with MCAS or Stall warnings etc.

I think it's the Romans they hade swords long before Napoleon, you carry the sword on the left side to be able to pull it with the right hand, then it will be easier to defend yourself if you ride or drive on the left side.
The same thing in a boat, the oar or side rudder is on the right side because most people are right-handed.

In English speaking culture most things in aviation are taken from Maritime to do with naming and ships are always she. I think German its masculine and Russian they always call aircraft he as well.

In Sweden boats are mostly female.
Apparently sailing ships are female but smaller boats can be male or neutrum , tugboats are always male.
And Viking ships, if never so sailing, was he.
The word for them was dragon "drake".
One famous one was "The Long Snake ".

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

My favorite explanation is that in England the Coach driver sat on the right so as to have more room to swing his whip.
This advantage would also apply to the use of weapons.
The same principle applied in America.
The driver sat on the left so that the shotgun guard had better access to his weapons.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I don't know what the current certification standard is on stall systems. As such its just a indication system. Its when it gets linked into other things that it explodes in complexity and redundancy.

Napoleon was something to do with driving on the other side I seem to remember. Your right handed explanation is as I remember it.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Napoleon was something to do with driving on the other side I seem to remember.
Do you mean on the right, right side?

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I have driven both it makes no difference to me. When you drive a vehicle that's meant for the other side that's when it gets dangerous in both systems.

http://www.b737.org.uk/stallwarningsys.htm

It seems the stall system and feel system is the same since the 1960's 100.

And the stick shaker is in series so both fire if triggered. All other planes its a dual independent system so if you cancel one side the other continues to work.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

God morning..
Well I been driving in Ireland no major problem other than when you get to a roundabout and there is no traffic, god so confusing.
Not only that you should drive on the wrong side but then you started to think about whether you should drive through the roundabout counterclockwise or clockwise as well.
With traffic around it is just to go with the flow

Best Regards A

PS. Most roads were so narrow that it was not possible to determine whether you were driving on the right or left side.

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Quote (Alistair Heaton)

I have driven both it makes no difference to me. When you drive a vehicle that's meant for the other side that's when it gets dangerous in both systems.
I fully agree. Talk about engineering failures and disasters. Don't know if it exists elsewhere, but in St. Croix US Virgin Islands, all the cars seem to be LHD (including rental cars), yet driving is on the left side of the road. Nearly had a crackup on the way to the hotel last summer. In fact, a few minutes earlier, on leaving the airport, I kid you not, I had correctly taken the left side of a two lane road and had a truck bearing down on me on my side until it veered off into a side road, leaving me confused as hell until I reached a road with significant traffic giving me a frame of reference.

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Well after coming back from Ireland I went of the main road one day into the wood to se if I could find some mushrooms, when I was driving out on the main road again where there was no traffic as far as the eye could reach, I thought something felt very strange until I realized that I was driving on the wrong side of the road.

I was with the same thing before Christmas someone had managed to drive off the highway and ended up on the wrong side of the road division there were two lanes going in both directions and came driving towards me in my lane just over a bridge crest it was just undone that it became a frontal collision if they did not turn away.

BR A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Lets keep the LHD/RHD thing to a different post eh?

I've asked this before and can't recall the answer, but my understanding is that on the 737, all vintages, the FCC used by MCAS and other functions switches sides after every flight once you power down. And how do you know which one is active?

As in both instances Lion Air and Ethiopian, it seems that in both instances it was the captains side FCC which received bad AoA information and hence everything started going wrong from there on. So on a 50% likelihood this was one of the first holes in the swiss cheese.

Is there / was there a chance to switch FCC in mid flight or is this something that just isn't done or isn't practical? On Airbus because you have three, I presume one with bad data compared to the other two just shuts down and gives you some alarm that it needs fixing later?

Now that the 737 max looks at both FCC or AoA data, to discover an inconsistency does this (only one FCC active) still apply?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I had thought the british right hand steering was adopted from the railroad engineers side, which in turn may have been adopted from the boat pilot's preferred side. The early US cars might have chosen the left side due to the difficulty of shifting the early transmissions implied the stronger right hand be used to force the tranny into gear.

"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

LI, I think the active FCC switched every reboot, though I'm not a primary source on that.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Don't know about Boeing. But there is usually what's call ed a reversion panel which allows you to cycle through the various sensors and data sources.

And it's reasonably easy and we some times swap sides out of choice for nav . You wouldn't normally fiddle with the flight control computers unless told to by a checklist.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Quote (LittleInch)

Now that the 737 max looks at both FCC or AoA data, to discover an inconsistency does this (only one FCC active) still apply?

The way, I understand it, is that both AOA sensors are evaluated for the alert "AoA sensors not ok" but this is just an alarm no function.

It was only the active FCC that used its own AoA sensor (just one for the MCAS function) and then evaluated it together with speed and other things to se if there was a stall and if the MCAS was to bee turned on.

I have also been wondering, if it automatically changes FCC every flight was it then reset before the next flight, since it also got the same problem.
But if it hade not been reset it would not have made such a big difference in the end since, flight 3 would probably had crashed if the second one didn't.
Since they did not understand what the problem was.

Best Regards A

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Thankfully the pedals are the same for both. That would really screw with my head. With the driving...

Now you see why I call it a Frankenstein design the 737. It works don't get me wrong. But its an organically grown design so you just can't use any presumption or logic with it. Makes trouble shooting extremely difficult.

If it was proper FBW certification which Boeing moved heaven and earth to avoid having to do then it would be covered. But that would have added 2-3 years and they were already 18 months behind the Neo and would have required more than 30 mins on an Ipad of training.

BTW this is tech pilot and examiner level of system knowledge working out how it all interacts that we are doing here in this discussion. The normal line pilot wouldn't normally go near it or if they are so inclined have the opportunity to brainstorm with like minded individuals and work out what's really going on. And remember that this is just a couple of systems out of 20-40 of similar complexity.

The philosophy of system knowledge required has also changed over the years. They really don't want you to be able to get inventive. They just want you to run the checklists. Jetstream theory course went all the way down to how the fuel controller meters fuel and the various modes the prop functioned in. Q400 not a thing. Its an engine the FADEC deals with the prop and the power you demand it and it will provided it. A220 there it is even more weighted to where the various switches are and not what the switches actually do to the big picture.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Wrap around fuel tanks eh? What can possibly go wrong?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

AH-- That's kind of the management style I'm used to after working for 40+ years. You can make yourself look better by making your peers seem worse.

The more you know, the more you know you don't know.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

The fuel tank stuff is a mess after the accident referred to in the article.

Its again this grandfathering. Boeing stuck with electrical submersed fuel pumps, everyone else went to motive flow pumps 40 years ago...

To be fair it is a valid point although I suspect it might not be as bigger problem to solve as Boeing thinks. The market for them isn't really in FAA airspace anyway.

I suspect its more to do with single type qualification and Boeing having nothing that could even remotely be stretched to do the same job. But it will cut into their wide body markets which already getting hammered for a variety of issues some of which are not Boeings fault.

Being able to send a crew short/medium haul for a number of days and then send them on a ultra long followed by the required days off makes rostering very economical even if it kicks the hell out of the crew. It means the airline can get 20 days work a month out of a crew instead of 10 days doing ULH.

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Turns out airbus have already got this feature on other aircraft, And many aircraft before have also had it including MD and Boeing.

They have a fix already for another type which is a Kevlar liner bag.

But to note the forum that the comment was made in is one of these regulator peer review processes. Boeing was completely right to highlight the issue.

Anyway saw this but didn't want to start another thread and thought those that would be interested would see it here.

Its a bit personal for me because I ended up stuck in Vilnius for 6 hours while they sorted it all out. And then saw it everyday I was in Tallinn.

But its a good example of a FBW airbus crew machine interaction accident triggered by a technical issue.

https://youtu.be/bo-S3kAInB8

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I guess the 'fat lady hasn't sung', yet. From a recent eMail from Change.Org...

"Dik — Over 346 people lost their lives in two crashes involving the Boeing 737 Max airplane. Years later, experts say that the model is still unsafe for use and countries like China and Norway have banned or are questioning their usage. This petition is calling on the federal government to ban the 737 Max in Canada, and call a public inquiry to find out why the 737 Max was approved in the first place. If you think that the 737 Max should not be used in Canadian airspace, sign today."

Not to worry... the Canadian government doesn't often listen to the people, either...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I vaguely recall from my first year economics class that monopolies are bad, and duopolies are only less bad. Here we have a de facto duopoly.
Maybe transport aircraft manufacturing needs to become a regulated public utility.

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

or maybe just properly regulated...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

Quote:

or maybe just properly regulated...
Isthat a typo?
Did you mean "just poorly regulated?"
No problem with poor regulation.
The agency is already in place.
The FAA.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

then maybe they should do their job then...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

RE: Boeing 737 Max8 Aircraft Crashes and Investigations [Part 8]

I banned 737s from my personal space. Not important to me if govs do, or don't agree with my policy.

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