I'm posting this because I can't believe what I'm hearing. First, a bit of background. I work for "the airline that just grounded 34 MAX aircraft" as a line mechanic. I had two weeks of formal training on the MAX in August.

Since the grounding of the fleet, I've made it a point to talk to the pilots about the issue, and every one has been confident that the issue has to do with uncommanded elevator trim, and can be controlled by deactivating the stab trim. This is what they're being told to do by their training department to do to deal with the problem. I think they're being done a great dis-service.

One of the things we covered (briefly) in school was the MCAS system, what it is, and why it's there. It seems in creating the MAX, Boeing started with the existing NextGen airframe and hung larger, heavier engines on it. So much larger, in fact, that they had to lenghten the nose gear strut by 8" to make enough ground clearance for the engines. The new engines are also quite a bit heavier, and because of their size had to be mounted farther forward, which moved the aircraft's center of gravity forward. Then, they discovered that the original NextGen horizontal stabilizer they used didn't have enough authority at lower airspeeds to counter the new, farther forward CG. Their solution was a stroke of engineering brilliance.

Since the wing is swept back, they found they could use the outer spoilers to kill some of the lift generated by the outer part of thee wing, which, due to the sweep of the wing causes the wing's center of lift to move forward. This brought the center of lift and the center of gravity back together where they should be, and avoided the expense of providing a larger horizontal stab- which would have also caused more drag and fuel burn. This is what the Manuvering Control Augmenting System (MCAS) does. Pure genius! The MCAS was to only work at low airspeeds when it was needed. At higher speeds the elevator has enough authority to do the job.

The problem is- since this system was to run automaticly in the background, they didn't bother telling the pilots about it. Or how to defeat it if and when it malfunctions.

So, there you are in flight, and the pitch of the airplane starts to change uncommanded. Your training dictates that you treat it as a run away stab trim issue, and then you notice the stab trim wheels aren't turning. What's your next move going to be?

I've seen over and over in the news where Boeing's going to come up with new software that's going to fix it. Until they inform the cockpit crews and provide a way of over riding it, I have my doubts.

Porosonik.

quote:

The problem is- since this system was to run automaticly in the background, they didn't bother telling the pilots about it. Or how to defeat it if and when it malfunctions.

I have been waiting for someone to post on this issue, as we seem to have folks on here pretty knowledgeable on flying. My understanding is that they did come up with a software solution to the problem, but it was counter intuitive to the pilots, so, without sufficient training and familiarity, pilots might make the problem worse. Just my 1 cent!
Peter.

It seems to me that as long as you try to fix a hardware problem by revising the software, you’re still going to have a hardware problem.

Porosonik.

Who needs the FBI when we’ve got this dude? Interesting info, thanks.

Spot on from what I had heard. 2 Degrees of positive pitch in the engines to diminish the possibility of a nacelle strike on landing. When power was applied it naturally created a pitch moment which the airplane, without pilot input, automatically trimmed nose down. Pilot reaction to an uncommanded pitch down was a power application creating another pitch up and another uncommanded pitch down. On and on. Good post, thanks

Great info appreciate the insight guys. A current Air Canada (they have MAXs in the fleet) pilot I used to fly with feels that Boeing pushed an old design too far to avoid recertification costs. The engines being the crux of the issue, as they truly don’t fit on the existing design and required a slough of patchwork workarounds.

I think the plane naturally has the potential to work great, I fly lots of aircraft that are imperfect, and engines are one of the most common ways to mess with a good design. Take the Bell 205 vs the 212, the entire fuel system in the 212 is an afterthought with needless complexity compared to the 205 (Huey).

Same revolution is happening to the 737, an ancient though solid design being tweaked and tweaked until naturally problems pop up. Just as the 212 is now a solid machine I’m sure the MAX will be too. But it’ll always be imperfect compared to a fresh slate, though even those have their issues initially (787 for example).

I like Boeing’s pilot centric philosophy more than Airbus’ equipment centric (also has had its issues, remember Air France 447 off Brazil) and hope they resolve this quickly. Shame hundreds of people had to die to fix it, though,

So this morning's paper says they're going to add yet another warning light on the panel for free instead of for $6700, as opposed to cross-checking VSI that would indicate a climb (stalled aircraft don't climb too good). I'm only a low-time VFR pilot but it seems like papering over something that is well beyond papering over.

Why is there not a mission-aware software component that cross-checks semi-autonomous systems, and how could a failed angle-of-attack sensor go un-noticed?

I don't fly the 737, but if I had an unresolved elevator issue (the nose is dropping and I'm pulling up hard) the first thing I'd do would be to kill the stab trim. It's an immediate action checklist on most airplanes. The cutoff switches are right next to our knees.

Second, if that didn't stop the nose down issue I'd reach up and turn off the entire autopilot system. At that point, manual or alternate trim systems exist on almost all modern aircraft which will bring the plane back towards normal. At that point you can delve into the books, ensure the plane is stable and immediately put it on deck at the nearest suitable airport.

After the Alaskan Air crash in 2000, it was clear that if you ever had a control issue you should immediately land and not trouble shoot while airborne. Not like they really had a chance...

Boeing is going to get hammered for this and they'll deserve it. Their reputation for producing a pilot's airplane has taken a serious hit.

It’s a shame, really. The ‘37 has amassed a truely stellar reputation over the last 50 years, but they pushed it just little too far this time. It’s looking like this is the plane Boeing’s going to regret building.

Porosonik.

First course of action in a different A/C checkout. Find the trim circuit breaker and auto pilot disconnect and circuit breaker. Memory Item, remember their position.

I've seen over and over in the news where Boeing's going to come up with new software that's going to fix it. Until they inform the cockpit crews and provide a way of over riding it, I have my doubts.

Just another airplane that can't fly without computers to control it. Modern Aviation.

Grizz

A7Dave and Bentaframe, take a look at the OP's post above. It appears the MCAS system has nothing to do with runaway stab trim.

Seems more akin to a "stick pusher" system. It's been more than 20 years since I flew it but I seem to remember the MD-80 having a "stick pusher" to counter excessive high angle of attack flight (or more accurately described, I believe it activated upon excessive pitch attitude without regard to actual AOA [typical Stupid 80 Rube Goldberg rigging, but I digress]). And I seem to remember (from the sim) that once it's activated, you are along for the ride until it disengages itself AND there were no pilot actionable procedures to deactivate it. If the MCAS system works in this same manner, and the MAX pilots didn't receive training on the system, Boeing is going to be in deep manure.

quote:

Originally posted by Todd Williams:
A7Dave and Bentaframe, take a look at the OP's post above. It appears the MCAS system has nothing to do with runaway stab trim.

Seems more akin to a "stick pusher" system. It's been more than 20 years since I flew it but I seem to remember the MD-80 having a "stick pusher" to counter excessive high angle of attack flight (or more accurately described, I believe it activated upon excessive pitch attitude without regard to actual AOA [typical Stupid 80 Rube Goldberg rigging, but I digress]). And I seem to remember (from the sim) that once it's activated, you are along for the ride until it disengages itself AND there were no pilot actionable procedures to deactivate it. If the MCAS system works in this same manner, and the MAX pilots didn't receive training on the system, Boeing is going to be in deep manure.

I think you’re catching on. The horizontal stab on a ‘37 (and a lot of other aircraft for that matter) is moved by a big jack screw, located inside the fuselage just forward of the APU. The jack screw is powered by two electric motors- a big one and a small one. The small one is controlled by the autopilot by a signal that comes from the Flight Controll Computer (FCC). The big motor is controlled by the trim switches on the yoke. The larger trim motor has enough power to defeat the smaller autopilot motor as a last resort. The jack screw can also be turned manually by the trim wheels on the center pedestal, through cables that run the length of the airplane. As I understand it, the trim wheels can overcome both trim motors.

If this were purely a trim issue, the pilots should be able to overcome it by trimming manually. This doesn’t seem to be the case.

Porosonik
,

Great info, thanks, hope they get it figured out before anymore people get hurt.

I only had a few years flying a glass cockpits. But in that time I noticed that my instrument scan and overall awareness seemed to fall off. I don't know if it was age or just having it all right in front of me that caused it. I have often wondered if pilots that have only flown the modern cockpit might be a little weak on some of the basics.

When you hear of a crew losing an airplane because of loss of airspeed or or some other instrument(s) anomaly you've got to wonder. Not disparaging the pilots but maybe questioning the training and systems regimes.

Here is an interesting link to an AOPA article that quotes a US Representative Pilot and his concerns...ie training and experience>>>

https://www.aopa.org/news-and-...-concerned-about-for eign-pilot-training?fbclid=IwAR1cTsF0CllL-XindfNUXYLJF683OS0YJS-aRy6iQxy0vhW490YFbJypEa4

I can remember my old retired Air Force fighter pilot, and Boeing Sim Instructor, Instrument Instructor in the 80-90's.....say>>> Foreign airlines only train to fly the automated systems, US airlines/FAA dictate hand flying the aircraft until you reach Type Rating Standards, then they can familiarize with Automated Systems...and how to "DEAL" with them!!
Seems this whole thing might be Training and Experience related....the captain on Lion air, 31 years old, and I have heard rumor the Ethiopian copilot had 250 hours TT!!??
Well, in 1967 I was offered 2 US airline pilot jobs...I had 250 hours of Cherokee time, Commercial and Instrument. Lots has changed since then after the Colgan Air accident...now 1500 hours to be in the Right seat with aircraft over 19 pax>>>tough, but I think it is the right thing to do.....FOR SAFETY!!
BUT---ALWAYS FLY THE AIRPLANE!!

quote:

Originally posted by Porosonik:
It’s a shame, really. The ‘37 has amassed a truely stellar reputation over the last 50 years, but they pushed it just little too far this time. It’s looking like this is the plane Boeing’s going to regret building.

Porosonik.

-300 and -400 were not exeempt of issues and some passengers and crew are no more here to talk about it ...

quote:

Originally posted by medved:

quote:

Originally posted by Porosonik:
It’s a shame, really. The ‘37 has amassed a truely stellar reputation over the last 50 years, but they pushed it just little too far this time. It’s looking like this is the plane Boeing’s going to regret building.

Porosonik.

-300 and -400 were not exempt of issues and some passengers and crew are no more here to talk about it ...

There was the tail-wagging thing, and the elevator spool valve thing, not sure what else there might have been that never made the papers.

Here is an interesting perspective from a Corporate Aircraft Chief of Maintenance says about a "similar issue" on Falcon 50's-

"I have been reading about this too. Sounds like a faulty AOA sensor caused the computers to miss-compare. Also read there is only one AOA sensor on the MAX. If only one sensor then how can it get an input miss compare.

On our Falcon 50EX's we were constantly replacing AOA sensors due to miss-compare indication on PFD's. Most AOA sensors did not even make it out of their warranty period. I had expressed concern about AOA sensor reliability many times. Never went very far, except was told our sensors were rheostat type. Newer aircraft were digital making them more reliable.

So if the AOA probe on the MAX is only a single probe. I do not understand how it can get a input miss-compare? perhaps duel sensors in one unit. Then there is a reliability issue, these are basically new A/C. Why are the AOA sensors failing so soon."
AOA is Angle of Attack sensor/indicator.
Again, it sounds like this being a pervasive problem, it gets back to FLY THE AIRPLANE!!

quote:

Originally posted by 470EDDY:
Here is an interesting perspective from a Corporate Aircraft Chief of Maintenance says about a "similar issue" on Falcon 50's-

"I have been reading about this too. Sounds like a faulty AOA sensor caused the computers to miss-compare. Also read there is only one AOA sensor on the MAX. If only one sensor then how can it get an input miss compare.

On our Falcon 50EX's we were constantly replacing AOA sensors due to miss-compare indication on PFD's. Most AOA sensors did not even make it out of their warranty period. I had expressed concern about AOA sensor reliability many times. Never went very far, except was told our sensors were rheostat type. Newer aircraft were digital making them more reliable.

So if the AOA probe on the MAX is only a single probe. I do not understand how it can get a input miss-compare? perhaps duel sensors in one unit. Then there is a reliability issue, these are basically new A/C. Why are the AOA sensors failing so soon."
AOA is Angle of Attack sensor/indicator.
Again, it sounds like this being a pervasive problem, it gets back to FLY THE AIRPLANE!!

Rheostat, as in potentiometer, with wiper and resistive element wear? Good grief. Are these things out in the open where they can hit birds?

https://www.eetimes.com/document.asp?doc_id=1334482#

Same issue with throttle position sensors in cars. Fred Kost (working at Stackpole, at the time) told Ford, GM, and Chrysler in the late 70s that sliding-contact potentiometers would never have the necessary reliability for that application. They did it anyway for cost reasons, and replacing them has been a little cash cow for dealers ever since.

Here's another commentary-

Sent to me from a non pilot who works for a Chinese company and flies constantly.







Subject: 737 MAX --The rest of the story

Very excellent explanation of what is going on in our “modern society”
Forcing unqualified people to do tasks they are simply educationally not able to grasp.


Something from a Retired Navy Capt who was a Carrier Maintenance Officer in the Pacific and Atlantic.
Subject: 737 MAX The rest of the story

> For those interested in the recent spate of accidents involving Boeing's
> newest 737 variant, the real story of what is going on behind the
> scenes is largely not being reported.
>
> It was interesting to note that President Trump alluded to the problem in a
> round about way, but unless you are a pilot you probably missed the point.
> In essence, President Trump was saying that technology is a poor
> substitute for a qualified pilot in command.
>
> One of the most basic skills a pilot learns from day one is energy
> management of the airplane. If the plane is too slow, it will literally
> drop from the sky. Too fast and the wings/airframe can come apart with
> disastrous consequences.
>
> In the history of commercial aviation in the US and western countries, the
> first crop of pilots to enter commercial service were the post world war
> two pilots. Those guys were the real deal and not only hand flew almost all
> of their hours but also in some of the most demanding conditions. The
> second wave were the airport kids who just fell in love with the idea of
> being a pilot and scrimped and saved to take lessons. Both categories of
> pilots were skilled in the art of aviation.
>
> With the explosion of second and third world travel, there were not even
> close to the amount of skilled pilots to fly the thousands of new
> generation planes coming out of Airbus and Boeing. Cathay Pacific, a
> Hong Kong airline, was almost exclusively piloted by british pilots,
> However the new asian airlines wanted asian pilots to man the cockpits...often
> with disastrous results. Asiana flight 214 crashed in SFO in 2014 because the
> pilots did not know how to hand fly the plane when the ground based
> approach ILS was out of service.
>
> Boeing, the FAA and worldwide aviation agencies track not only accidents,
> but also INCIDENTS…crap that was going sideways but didn't result in a
> crash. The number of unqualified pilots from asia and africa was plain to
> see in the number of errors being committed on a daily basis.
>
> To make a long story short, airbus saw this eventuality decades ago and
> implemented automatic safety systems in anticipation of unqualified
> aircrews. Boeing resisted for a lot of very good reasons...but after the
> Asiana crash, the chinese government basically told Boeing to
> "idiot-proof" the 737 as china would end up being the biggest purchaser of that model.
> Since Boeing had opted not to add automated control systems (which often
> override pilots inputs) they were forced to apply a band-aid solution
> which, unfortunately, was not done well. Only one sensor was driving some
> very complicated algos which worked against the pilots decision making inputs.
>
> The fact that the asian and african pilots were essentially unqualified is
> highly embarrassing to the respective governments and Boeing kept it quiet.
> When ALPA (the pilots union) reps found the system was added without
> informing the pilots, they went insane...
>
> However, what they DON'T know, is that the MCAS system can be enabled or
> disabled per plane, and can be done remotely on a real time basis via
> uplink. The US airlines management, due to the superior training and
> piloting skills, opted NOT to activate MCAR...but the asian/african carriers
> did. That is why most of the “ crappy" airlines self grounded while all the
> major US airlines are still flying without a problem.
>
> Its a very PC issue, but basically comes down to 30-40% of the global pilot
> population are really not qualified to be pilots, but just data input managers.
>
> Additional comments. Friends who will remain anonymous (by initials only),
> long ago confirmed the above. One (IM) who worked under a Boeing contract
> giving simulator training to South Koreans, just shook his head when he
> related tales of cockpit coordination. It was a South Korean flight 007, a
> Boeing 747, killing 269 persons, that the Russians shot down because of a
> one digit error entered into the INS system.
>
> Another (BH) who retired from Delta a dozen years ago once told me he would
> never allow his family to fly on a foreign air carrier. There are a few
> exceptions to that, I'm sure. We are flying COPA in a couple weeks, they
> have had only one fatal accident back in the 1990's, the result of an
> instrument failure.
>
> The old adage still applies: *To make things on the ground appear smaller,
> pull back. To make things on the ground appear larger, keep pulling back!!*

quote:

That is why most of the “ crappy" airlines self grounded while all the
> major US airlines are still flying without a problem.

Well, 470EDDY, I'm glad you have solved the problem to your satisfaction. Read the papers lately (or in your case watched FOX News)? US Airlines still flying the plane? Read about the preliminary results of the Ethiopian investigators? Well, they are just a bunch of WOGS, right?
Let's just wait and see.
Peter.

PETER-
Don't shoot the messenger...I just passed on a commentary that had some interesting "stuff" in it!! I didn't write it and I am not making any predictions or casting blame....it's all out there to read and see on TV...but how much can you believe today??

quote:

but how much can you believe today

Well I am sure that to you it is all "FAKE NEWS" (except for Sarah Palin and FOX News)!
Peter.

quote:

Originally posted by Peter:

quote:

but how much can you believe today

Well I am sure that to you it is all "FAKE NEWS" (except for Sarah Palin and FOX News)!
Peter.

... he said a week or so after the largest main stream media story collapse in history!!!

quote:

Originally posted by Todd Williams:

quote:

Originally posted by Peter:

quote:

but how much can you believe today

Well I am sure that to you it is all "FAKE NEWS" (except for Sarah Palin and FOX News)!
Peter.

... he said a week or so after the largest main stream media story collapse in history!!!

And YES, I would believe ANYTHING Sarah Palin told me!!

quote:

. he said a week or so after the largest main stream media story collapse in history

HUH??!! Do you have stock in Boeing? Just lost 17 points TODAY! "a week or so after the story collapsed"??!!
What is the matter with you guys? Why circle the wagons when we don't know the story? Why not just wait and see? Is it remotely possible that Boeing messed up? Is it? Is it remotely possible that it was not the fault of ignorant, unqualified, third world pilots? Why does it matter? Is it unpatriotic to NOT blame the pilot?

"YES, I would believe ANYTHING Sarah Palin told me!!"
Says it all!!
Peter.

quote:

Originally posted by Peter:

quote:

. he said a week or so after the largest main stream media story collapse in history

HUH??!! Do you have stock in Boeing? Just lost 17 points TODAY! "a week or so after the story collapsed"??!!
What is the matter with you guys? Why circle the wagons when we don't know the story? Why not just wait and see? Is it remotely possible that Boeing messed up? Is it? Is it remotely possible that it was not the fault of ignorant, unqualified, third world pilots? Why does it matter? Is it unpatriotic to NOT blame the pilot?

"YES, I would believe ANYTHING Sarah Palin told me!!"
Says it all!!
Peter.

Man, Peter. You are so eat up with it you can't see the forrest for the trees.

My comment about the story collapsing has nothing to do with Boeing or aviation at all. I was commenting on your continued rants against the Fox News channel and the so called Fake News that the liberal ilk so often mock, when in fact all the main stream media outlets OTHER THAN FOX bet their reputations on the Trump/Collusion hoax and the Mueller report. When it was proven false, the story collapsed, yet guys like yourself still want us to believe that Fake News isn't a problem and that Fox News is the one with the bias?

That's why the emoticons. In fact, I think your response above calls for another dose.

quote:

My comment about the story collapsing has nothing to do with Boeing or aviation at all. I was commenting on your continued rants against the Fox News channel and the so called Fake News that the liberal ilk so often mock, when in fact all the main stream media outlets OTHER THAN FOX bet their reputations on the Trump/Collusion hoax and the Mueller report. When it was proven false, the story collapsed, yet guys like yourself still want us to believe that Fake News isn't a problem and that Fox News is the one with the bias?

My apologies Todd, I thought that the "story" was about the two Boeing 737 crashes. This is the Aviation forum, after all. I do not rant about FOX news! In fact I regard FOX news and its adherents as a huge joke! As to the Mueller investigation, it was authorized, took it's course, was executed in a very professional fashion (FOX News adherents will have a different opinion, not their own but the one that FOX News wants them to have). What's not to like about the process? Now, what does all that have to do with the Boeing crashes?
BTW, you seem to be the one who is "eat up"!!
Peter

Peter, look back over this thread.

You sir, not me, are the party that brought an unrelated discussion of "Fake News", Sarah Palin, and Fox News into an aviation discussion.

Re-read your first response to me, concerning Boeing and "circling the wagons". Compare that comment against my earlier posts on this aviation thread as well as others on this forum addressing the 737 Max issue. I believe you'll find that I, as a commercial pilot, have advocated for abstaining from the usual jumps to conclusion the media sources seem to make, and instead, suggested we all wait until the official incident reports are released.

To put a finer point on the subject, specific to your first comment to me, insinuating a circling of the wagons and protecting Boeing, I'll direct you to my comment made earlier in this thread ... "If the MCAS system works in the same manner, and the MAX pilots didn't receive training on the system, Boeing is going to be in deep manure".

Peter, I say you are "eat up" with it and I stand by that statement, as inflammatory as I realize it is. Specifically what you are "eat up" with is some level of hatred of anything that doesn't fit your particular political leanings. So much so that you can't respond to someone's posts without relying on politically motivated talking point mantras such as "drill baby drill", "fake news", "Sarah Palin", "Trump", "fox news", etc. I often read your comments and wonder how you stray from the topic at hand and bring in these liberal "mocking" points?

As to 470EDDY's post about a story he was given, again, I say let's set aside the jumps to conclusion and wait on an official incident / accident report. That said, there are some points in the story that have some merit. Unlike your interpretation, evidenced by your use of the term WOGS, I don't see the commentary as a racial slur, but rather a fairly well known, at least within the aviation industry, difference in training focus. You can see evidence of it in the Boeing and former McDonell Douglass designs as compared to the Airbus designs. Based on the factory locations of each, I suppose one could call one the American and the other, European, design focus whereby the Airbus design does focus more on management of the flight automation systems whereas the Boeing design has heretofore placed more emphasis on pilot interaction with the plane and using the automation systems to relieve a portion of the workload.

I don't see that as a racial slur in any way, shape, or form, but a realistic observation of how two different and competing companies have designed their planes and developed training regimes in their support. From there, it is an easy assertion that contract training companies, utilizing programs primarily designed around the "Airbus" focus of system management could be adapted to training on Boeing equipment. In other words, training utilized by African and Asian airlines, or simply, smaller carriers that aren't large enough to support their own simulator facilities, through the contract training programs that are prevalent in the industry, if domiciled in Europe, are more likely to train to the automation system management focus.

I believe the commentary posted by 470EDDY is nothing more than an opinion he received from someone, on whether or not that training focus is the better of the two or not. And further, it appears, from reports, that Boeing may have adopted the same system management focus concerning the MCAS system on the MAX aircraft. And as I stated earlier, if they did, and didn't properly develop the training program to teach pilots how to deal with the system, especially if the system resulted in crashes while it was working CORRECTLY, in other words, the pilots misinterpreting what was correctly happening with the jet, yep, Boeing is going to have hell to pay. If the MCAS system is actually a dangerous and unworthy work around, and they passed it off through certification fraud, Stand the Hell BY!!!

Now, take my comments above regarding 470EDDY's post and compare them to your rantings on Fox News, Sarah Palin, and Fake News and tell us again, exactly whom is "eat up" with it?

Seems the National news is now reporting bird sstrike or other FOR strike to the AOA!! Reports are there is only ONE AOA on the new 737 MAX, not two. Note the comments above re Falcon biz jets issues .

My question, being an old stick n rudder guy, WHY ARE THESE GUYS ON AUTOPILOT IMMEDIATELY AFTER TAKEOFF?? WHERE HAS THE JOY OF FLYING GONE??

WOW, I just read in a local aviation rag that by 22028 there will be a shortage of 45,000 Biz Jet pilots!!

Wish I was young again!! That is really fun flying.

Cheers

quote:

Originally posted by 470EDDY:


My question, being an old stick n rudder guy, WHY ARE THESE GUYS ON AUTOPILOT IMMEDIATELY AFTER TAKEOFF?? WHERE HAS THE JOY OF FLYING GONE??

I know, right?

Most of the guys I flew with, as it was taught in training, would call for "autopilot on" as soon as clean up was completed.


Going back to the discussion in my comment to Peter above, in response to your earlier post EDDY, I lost a good friend two years ago partially due to an over reliance on automation.

He was flying his helicopter home from taking his wife out to dinner. He also owned a jet and was fully qualified in the jet, but had not completed an instrument rating in the chopper. I don't know why not. I guess he figured he had the IFR rating in the plane so it would cover him for IFR helo operations.

Anyway, he took off in a pretty low ceiling environment, 1200 broken, and attempted to fly home VFR at night. He encountered IFR conditions and according to the final accident report, entered a 60 degree left "wing" down attitude. He appears to have corrected that but in the process ended up in a 45 degree nose high attitude. At that point, he selected "airspeed hold" and attempted to engage Trim Control. The airspeed hold mode engaged but Trim Control did not. It appears he attempted to use the autopilot to save himself from the extreme disorientation he found himself in. The result is the chopper flew into the ground at max forward speed in a 30 degree nose down attitude, killing himself and his wife.

There were a lot of things wrong in that event. First of all, not being fully qualified for the flight environment. But it appears someone, somewhere, taught him to use the autopilot to stabilize the aircraft upon IFR attitude disorientation. A perfect example of relying on automation instead of physically flying the aircraft directly "pilot to machine".

Todd,

BANG ON!! Fly your machine...and believe the gauges!! Don't fly beyond your skills!!
Sorry for your loss, it is always very difficult for old aviators to lose friends doing the things we love most.
Sadly on the MAX situation I speculate that Boeing will take a bust on the chops, BUT, I think a lot of this relates to the lack of training, and lack of overall EXPERIENCE by foreign airlines. US air carriers have experienced similar upsets and recovered ....only by shutting off the AP... EXPERIENCE and trained/ingrained reactions!!
As a general rule, my wife and I do NOT fly on Third World airlines and most foreign airlines because of this exact issue training,but also expectation of total experience, but also maintenance?? Personal limitation....and I think it is going to get worse as teh shortage of pilots deepens....glad I have most of my traveling behind me!!
Thanks for your support against our LIBERAL interloper!! SAEED should watch this guy!!
Cheers,

quote:

Originally posted by Todd Williams:
A7Dave and Bentaframe, take a look at the OP's post above. It appears the MCAS system has nothing to do with runaway stab trim.

Seems more akin to a "stick pusher" system. It's been more than 20 years since I flew it but I seem to remember the MD-80 having a "stick pusher" to counter excessive high angle of attack flight (or more accurately described, I believe it activated upon excessive pitch attitude without regard to actual AOA [typical Stupid 80 Rube Goldberg rigging, but I digress]). And I seem to remember (from the sim) that once it's activated, you are along for the ride until it disengages itself AND there were no pilot actionable procedures to deactivate it. If the MCAS system works in this same manner, and the MAX pilots didn't receive training on the system, Boeing is going to be in deep manure.

Todd,

I frankly can't come to any clear conclusion from everything I've read (now mid April). Available information seems to say that the MCAS control of the horizontal stab could be disabled by killing the Horizontal Stab switches. I don't know if MCAS is actually trimming the stab. It certainly isn't "runaway trim" in the normal sense, but "runaway trim" by a computer input.

The MD11 had several accidents and tail strikes caused at touchdown by spoiler deployment. The fix was software that counteracted, through forward control column pressure or movement to counteract the spoiler's nose up force (ie, not stab trim, but column forward pressure).

So, you may be right. Perhaps MCAS doesn't trim the stab nose down. Perhaps it is only a forward control column pressure. Nonetheless, if MCAS is actuating improperly, was the plane designed whereby positioning the Horizontal Stab switches to cutoff would disable MCAS?

It damn well should have been.

quote:

Originally posted by A7Dave:

quote:

Originally posted by Todd Williams:
A7Dave and Bentaframe, take a look at the OP's post above. It appears the MCAS system has nothing to do with runaway stab trim.

Seems more akin to a "stick pusher" system. It's been more than 20 years since I flew it but I seem to remember the MD-80 having a "stick pusher" to counter excessive high angle of attack flight (or more accurately described, I believe it activated upon excessive pitch attitude without regard to actual AOA [typical Stupid 80 Rube Goldberg rigging, but I digress]). And I seem to remember (from the sim) that once it's activated, you are along for the ride until it disengages itself AND there were no pilot actionable procedures to deactivate it. If the MCAS system works in this same manner, and the MAX pilots didn't receive training on the system, Boeing is going to be in deep manure.

Todd,

I frankly can't come to any clear conclusion from everything I've read (now mid April). Available information seems to say that the MCAS control of the horizontal stab could be disabled by killing the Horizontal Stab switches. I don't know if MCAS is actually trimming the stab. It certainly isn't "runaway trim" in the normal sense, but "runaway trim" by a computer input.

The MD11 had several accidents and tail strikes caused at touchdown by spoiler deployment. The fix was software that counteracted, through forward control column pressure or movement to counteract the spoiler's nose up force (ie, not stab trim, but column forward pressure).

So, you may be right. Perhaps MCAS doesn't trim the stab nose down. Perhaps it is only a forward control column pressure. Nonetheless, if MCAS is actuating improperly, was the plane designed whereby positioning the Horizontal Stab switches to cutoff would disable MCAS?

It damn well should have been.

Hi Dave,

Sure seems like a lot of mystery surrounding the MCAS system doesn't it? I'm interested to see what the final accident reports show and what the fix ends up being. I really hope the loss of life didn't happen due to cutting corners and hiding the fact.

HOLY SMOKE!! Did any of you watch Steve Hilton on Fox News on Sunday rip into Boeing in their "In the SWAMP" talk.... he covered the stinky connections of Boeing and Government going on for years, the manicuring of higher up Government officials who manage the government purchases...then they and their families are well placed high in the Boeing Management....of course relating to their old cronies still back in Government!! $67Billion of their ANNUAL Gross Incomes comes from Government, they showed various $100k donations to campaign funds...and over the last umpteen years $267 BILLION...yes with a "B"...spent in Lobbying the government. It was a pretty scathing commentary on SWAMP Politics!!
OH Boy....this could get messy....
Southwest Airlines recently announced cancelling flight schedules out to August 5 on all of their MAX aircraft....

quote:

R

Yep- it looks like the workaround to fix the original workaround is taking a lot longer than expected. Imagine that. Fortunately, I'll be retired before the MAX returns to service here at Southwest.

Still, it's amazing to see just how much "fake news" there is surrounding this topic. Everybody's still saying that the fix will be a software correction to the existing anti stall system. It isn't going to be that easy.

The whole reason MCAS was added to this airplane was because the elevator didn't have enough authority to do the job at all attitudes and air speeds. The existing SMYD (stall management/yaw damper) controls pitch via the elevator, but there wasn't enough elevator available for it to do the job. That's when the engineers decided if they couldn't move the CG to the center of lift (and thereby control pitch) with the elevator, they would move the center of lift to match the CG by controlling the part of the wing doing the lifting. That was what MCAS was supposed to do.

Also- the single AOA vane story isn't neccessarily true either. The MAX definately has two AOA vanes- one on each side of the fuselage just under the cockpit. It is my understanding that only the right side AOA feeds the MCAS, at least that's what the block diagram in my training book shows. This could very well be a factor in why the MCAS runs amok. Strange- Boeing usually designs stuff with multiple redundancy eight ways to Sunday.

Anyway- to deal with the root of the problem, they're either going to have to give the elevator more authority (larger elevator), or add a cannard to the nose to make up for the lack of sufficient elevator. Neither looks attractive from an economic point of view.

Porosonik.

quote:

Originally posted by Porosonik:

quote:

R

Yep- it looks like the workaround to fix the original workaround is taking a lot longer than expected. Imagine that. Fortunately, I'll be retired before the MAX returns to service here at Southwest.

Still, it's amazing to see just how much "fake news" there is surrounding this topic. Everybody's still saying that the fix will be a software correction to the existing anti stall system. It isn't going to be that easy.

The whole reason MCAS was added to this airplane was because the elevator didn't have enough authority to do the job at all attitudes and air speeds. The existing SMYD (stall management/yaw damper) controls pitch via the elevator, but there wasn't enough elevator available for it to do the job. That's when the engineers decided if they couldn't move the CG to the center of lift (and thereby control pitch) with the elevator, they would move the center of lift to match the CG by controlling the part of the wing doing the lifting. That was what MCAS was supposed to do.

Also- the single AOA vane story isn't neccessarily true either. The MAX definately has two AOA vanes- one on each side of the fuselage just under the cockpit. It is my understanding that only the right side AOA feeds the MCAS, at least that's what the block diagram in my training book shows. This could very well be a factor in why the MCAS runs amok. Strange- Boeing usually designs stuff with multiple redundancy eight ways to Sunday.

Anyway- to deal with the root of the problem, they're either going to have to give the elevator more authority (larger elevator), or add a cannard to the nose to make up for the lack of sufficient elevator. Neither looks attractive from an economic point of view.

Porosonik.

So, what you're saying is, it's going to take a redesign to fix the problem ? that could get pricey.

Grizz

That's pretty much the way I see it. They've pushed into production an airplane without enough tail feathers to properly control pitch in all regimes of flight, and compensated for the problem by adding a system to control pitch by altering the lift characteristics of the wing- the problem being this system sometimes seems to become possessed by Satan at the worst possible moment. Boeing has a problem.

I guess you can stuff a big block V8 into a VW Bug... but you should expect some handling problems if you do. That's what we have here. Boeing did this and then tried to tell us it was still a VW Bug.

Porosonik.

By the way- this isn't the only glitch in the system so far. A couple of weeks ago, Southwest was ferrying a MAX from Orlando to Mojave where the rest of the fleet is being stored. About the time they rotated, a fuel nozzle on one of the engines failed, burning a hole through the C-Duct and leaving debris on the runway. They declared an emergency and returned to Orlando. Looks like
that one will be spending some time there.

There are so few engines in existence, Boeing was resorting to removing the engines when the new airplanes were being painted and trucking them back to hang on the next airplane off the assembly line. The fuel nozzle in question is made by 3-D printing- there's no way to machine the internal shapes required by the design- and is one of the keys to the improved fuel efficiency of the MAX.

This is only one incident, but it could be a sign of further woes to come.

Porosonik.

I finally had a chance to go back and re-read all the posts so far, and noticed a common theme. Folks from the “pilot side of the house” have been trained from the beginning that the elevator is the only device that controls pitch. Full stop. End of story.

In this Brave New World of fly-by-wire aviation, that is no longer a constant.

MCAS was designed to control pitch independently of the elevator. It had to be that way, to “assist” the elevator when it runs out of effectiveness. Therefore, it has no direct physical connection with the elevator. No amount of treating it as an elevator trim issue is going to be effective, because it’s not the elevator position that’s changing the pitch. This is just one of the changes that need to be made in regards to pilot training.

Also, something new with the MAX is the “elevator jam landing assist” switch on the P5 overhead, just above the leading edge device position annunciatior (“pinball machine”). This allows pitch to be controlled as a last resort through the MCAS in the event of a disabled elevator. I guess the folks at Boeing thought this would be a nifty add-on so it wouldn’t be necessary to herd all the fat passengers fore or aft as a last ditch control method.

OK- rant off.

Porosonik