Very good job explaining things to some who may not have any aviation training. I am quite close to this situation. I will not say what I do or my experience, but what I will say is that after reading and hearing some of this preliminary report last week some of the questions I had were answered, especially the excessive airspeed. They obviously had a lot on their plate in a very short amount of time and at a crucial point in the flight with no room for error. This is where training and experience comes into play and it sounds like the captain had a large amount of it. It’s apparent they left the airplane at T/O power throughout the entire 6 plus min flight, and from what the report seems to say they did not power back to climb thrust because this situation got on top of them fast. There are a lot of irresponsible comments people are leaving that are bothersome. It’s very easy for people to say what they would have done in that situation with their feet standing safely on the ground. Yes, it bothers me that they never reduced power and that seems to be a contributor to this disaster. But the one thing that scares a pilot most is a flight control issue. The pilot workload, alarms, warning lights, low altitude, an extremely serious flight control issue and a host of other factors coupled with fear, sealed these poor people’s fate. There is a lot of blame to go around and this investigation is far from over. We need to find out some things starting with the faulty AOA sensor reading since that is where this entire situation starts (IMO) and why does the MCAS only take info from one AOA vane? There is a lot to be sorted out so why don’t we refrain from hurtful comments and not place any blame until we get all of the information. We all have different credentials and opinions but this is real life, not Xbox or some video game. Remember, family members from those who were killed in the tragedy could be reading and listening. It’s a small world with social media now. For all who perished in the Lion Air and Ethiopian Airlines crashes R.I.P
@blancolirio5 жыл бұрын
Thank you sir.! 100%.
@derricksteed34665 жыл бұрын
Well said
@thespecialist7865 жыл бұрын
This is a technical report and discussion so please kindly understand the focus is on the cause not all the other sensitive matters. We all respect loss nothing can change that fact.
@c8Lorraine15 жыл бұрын
A Jonesy Thank you for your explanation and your sensitivity toward the pilots and families who are grieving their loss.
@Menelik.videos5 жыл бұрын
Awesome comment, thank you very much sir.
@rickleger35285 жыл бұрын
Excellent job sir you have helped us non pilot folks understand how this crew tried to save the plane. I look forward to your continuing coverage
@leesherman1005 жыл бұрын
You've made the news media obsolete. Outstanding explanation of the facts. 5 stars.
@sietuuba5 жыл бұрын
Large TV channels definitely but news media is more than the vacuous talking heads on the telly with nothing but commentary and soundbites! There's, you know, actual press with journalists that dig deep into these things. In this MAX 8 case, read the reporting of Seattle Times for instance.
@christianwetzel21995 жыл бұрын
well, these are journalists who have studied journalism and have no knowledge of aviation or engineering whatsoever. the best they can do (which often they don't) is interview someone with expertise and give them 30 sec of airtime with several interruptions whenever it get's interesting. he on the other hand is a pilot and instructor. youtube = cut out the middle man
@algrayson89655 жыл бұрын
@Thomas Headley- "Fake" president?? Despite your preferred candidate not winning, according to the presidential election system prescribed in the US constitution Donald Trump won (the Republican primary and) the electoral college. Unless he was discovered to be constitutionally disqualified, he is the president of the United States. He is a documented natural born US citizen by being born to US citizen parents and by being born subject to the jurisdiction of the US. He was elected by the electoral college. He was over 35 on his date of being sworn in to office. He swore to support the US constitution. What further requirements do you think there are?
@Alvan815 жыл бұрын
@Tickey Horseman We don't "trust" the MSM, we are supposed to analyze data from MULTIPLE sources, attempting to determine which of those sources is accurate for that data point and go from there. Saying 'fake news', but not requiring the raw data -means you "trust" the guy claiming fake news. But if they won't provide the raw data, then trusting that person is a sucker play. It's very similar to the idea of redundancy.
@PatKittle5 жыл бұрын
We're not supposed to notice, let alone say anything if we do notice. But the fact is, Israel lobby billionaires control the "mainstream" media -- sometimes their supporters even brag about it.
@raildawg83385 жыл бұрын
MAX pilot here. Very well done Juan. Professional summary of what the pilots faced. Good job.
@hernanni55 жыл бұрын
Chuck Cummins Hi Chuck! As a Max pilot, do you know if western airline companies purchased the full safety MCAS system of the 737 Max, considering - if I have well understood - Lion Air and Ethiopian Airline had the standard configuration?
@raildawg83385 жыл бұрын
Hi Franco I don't have the answer to that. It's a good question.
@md9295 жыл бұрын
@@hernanni5 Only Southwest I believe. American might have purchased it as well but I'm not sure.
@peterpluim79125 жыл бұрын
Chuck Cummins it is mentioned in the NY Times article of 21st of March. American Airlines bought both safety provisions. Southwest bought the disagree light and did an after install of the angle of attack option. United Airlines has neither the angle of attack indicator nor the disagree light. The main issue here seems to be that other countries relied on the FAA approval. This will not happen again anytime soon, so I ‘look forward’ to President Trump defending the interests of Boeing against European countries who don’t trust the FAA anymore and will want to do their own certification tests. He’ll probably order retaliatory measures for Airbus planes and the Chinese will love it. What a world we live in.
@BenJaminLongTime5 жыл бұрын
It was very good to hear this explanation. I recently began working at Boeing was supposed to be on the 777x but got moved to the 737max to help out. The attitude toward this stuff is something to behold, people here really do care about the vehicle we are producing and the people flying on it. The aircraft are exceptionally well put together from what I can tell, and I am a junior in aerospace engineering working as a assembly mechanic currently so I get to know the vehicle pretty intimately but hearing the pilot side is great. I personally would not hesitate to fly on any of Boeing's planes, granted nothing will ever be 100% risk free. I also trust that the pilots in the US are some of if not the best and most knowledgeable about aerospace in the world and can only make things that much more safe. I am not even trying to throw a sales pitch for Boeing, I just really appreciate how careful they are when building these birds...
@8kigana5 жыл бұрын
Thank goodness for youtube, men like this host are available to explain in detail without major media network clown hosts interrupting him.
@blancolirio5 жыл бұрын
Great point thanks Chuimon!
@8kigana5 жыл бұрын
@@blancolirio welcome sir, thanks and keep 'em coming!
@seharsarahsikander5 жыл бұрын
YES!! And without the "Boeing stocks" graph in the top left corner showing us $$ money in the last week. Jesus. Makes my blood boil.
@esphilee5 жыл бұрын
Agree.
@wheelitzr25 жыл бұрын
I've heard a whole bunch of stuff today but have been waiting patiently to hear from you.
@antonystringfellow51525 жыл бұрын
The MCAS system was not incorporated simply to prevent a stall. It was developed to compensate for the larger engines, which have to be mounted further forward of the wing, so that the pilots wouldn't need expensive retraining to learn how to handle the extra pitch-up on throttle up. Instead, the MCAS would take care of that. The alternative would have been to increase the size of the horizontal stabilizer. That, like the retraining, would have added more cost.
@antonystringfellow51525 жыл бұрын
Excellent explanation though. Really excellent!
@gyrocon5 жыл бұрын
420 knots, in the weeds, hugging the stick... he made a choice.
@chrisjohnson46665 жыл бұрын
This lesson was learned 50 years ago by NASA..... If you're going to have a fly by wire system and a computer will have any ability to override pilot inputs then triple redundancy is appropriate... The aerospace industry standard is 3 independent sensors feeding into the flight computer or computers and polling those sensors... if one os giving jibberish and 2 match the one is discounted... if 2 fail the system is disabled and manual reversion or pilot control occurs... Why Boeing did not build any redundancy into MCAS and then gave it so much control authority boggles my mind... The cost would be one extra AOA sensor and some software additions... This error probably has fatally hurt the MAX aircraft its basically the DC10 all over again the PR will take years to shake... All over a software solution looking for a problem because some techy behind a desk thought a pilot couldn't recover from a stall????
@WilliamJones-Halibut-vq1fs5 жыл бұрын
@Asa MeredithI'm beginning to suspect that the architecture of the left right ADC (Air Data Computers) may have prevented the left and right sensor from being compared since the philosophy of the system is to move instruments from one side of the cockpit to the other to the wherever the pilot flying. Remember the B737 is built around a 50 year old architecture and is not a triple redundant fault tolerant architecture we see on Fly By Wire Systems on B787/B777/Airbus. It seems to have just two of everything. The Sensor Disagree Alert Seems to have been part of the optional Angle of Attack display and would have been computed in the separate computer in the display that was able to access data from both sensors. So I'm thinking there was some kind of system constraint that stopped the MCAS guy from accessing both sensors.
@davide.burden20435 жыл бұрын
Glad you survived the media frenzy at Oroville Juan. It's always good to see you, even when you have to give us hard news.
@riverratrvr92255 жыл бұрын
@Todd Cory wow!
@davide.burden20435 жыл бұрын
That's alottawatta
@186618735 жыл бұрын
I'm a retired 737 Captain and had many questions about the -800 MAX. You answered them all. Thank you.
@danjacobson98615 жыл бұрын
MAX8 not, 737-800. Two different airplanes.
@186618735 жыл бұрын
@@danjacobson9861: I stand corrected.
@soundknight5 жыл бұрын
@@danjacobson9861 (just for lay people like myself who may be crapping themselves because they thought they were on the same plane). Thanks
@blite28475 жыл бұрын
A lot better than the new gens. Do you remember how roll sensitive it was during a Flaps 40 landing...they computer enhance the spoiler and it feels like a Flaps 30. Also...a left and right cup holder.
@612nadiya5 жыл бұрын
As Private pilot with 200 flying hours and a year and half of non stop experience and now studying on my instrument, I have Learned a magnificent informations from you because, you are a professional commercial Pilots who knows not only flying a boing or Airbuse, you are well knowledgeable about the fundamentals of physics and aviation. Truly, a person Like you taking your time and posting these kinds of knowledgeable videos, truly means a lot for those many thousands of Aviation Lovers Like me whom wonder always why an Airplane fly on the sky and how a responsible pilot understands very well how to resolve in expected situation Wright away. Thank you so much.
@blancolirio5 жыл бұрын
Thanks Nahlah! Stay tuned...
@Bob_H5 жыл бұрын
THANK YOU VERY MUCH! You have been delivering the information so clearly that even those of us non-aviation people can follow.
@Nathanm79775 жыл бұрын
Sad all around. good report and demo about how and why it was hard to manually trim
@plsuh5 жыл бұрын
Good point on the difficulty with manual trim. In Juan's previous video on this topic he mentioned and linked to a video demonstration by Mentour Pilot on the runaway trim procedure. During that demonstration, both the pilot and first officer had to work the manual trim wheels together in order to adjust the trim. The first officer alone was unable to effectively work the manual trim wheel.
@drtidrow5 жыл бұрын
Seems like they decided it was too hard to manually trim the aircraft, so they reactivated the electric trim motor to use that.... and MCAS ran it back to nose-down trim again. Apparently they needed to cut engine power and reduce speed, so that the aerodynamic forces wouldn't be so severe on the stabilizer, and then use manual trim. Unfortunately it also sounds like they were too close to the ground and didn't have the time or altitude to do that. :-(
@joso55545 жыл бұрын
RayDT indeed, all the more with the already very high altitude of the airport itself !
@PetesNikon5 жыл бұрын
your account of the recorded events on board the Ethiopian flight had me on the edge of my seat. What tension and desperation we were witnessing...Thank you for explaining what went on. The more information that is available describing what went on, the more Boeing can find an effective solution
@hederoth78835 жыл бұрын
You have all the trustworthyness and authority of someone who really knows what he’s talking about. Absolutely brilliant. As you say, this will have ramifications beyond what we currently can imagine. Question is if Boeing will survive?
@wdhewson5 жыл бұрын
Used to fly to the Arctic in a corporate jet. Enjoyed being with the pilots. One pilot stated, "Three things of no use to a pilot, fuel on the ground, runway behind you, and altitude above you". Thanks Juan. We understand with your help. Timely too!!
@glasser28195 жыл бұрын
Great quotes. Why not listen to pilots feedback during the design phase??? They'll tell you how they like MCAS Version 0.1
@KSparks805 жыл бұрын
Did they ever tell you what to do if you're flying in the dark of night, engines out and going down, and you don't like what little of the cliffs and boulders you can see with the landing lights?? Turn the lights off.
@jaminthomas5 жыл бұрын
@Ardent Fan Exactly. I expanded on this in reply to another commenter. It was never Boeing's intention to reveal the existence of MCAS. Unfortunately, events have forced their hands and confidence in the regulators as the last bastion of protection is now shaken.
@montello335 жыл бұрын
You are great at reporting. Concise and to the point.
@s.roberts38395 жыл бұрын
Ahh, the days of reporting the actual event without possibilities, dodgy eyewitness accounts or advertising. Sooooo refreshing hey mate
@specforged56515 жыл бұрын
Thank you very much for your educated post. This is a rarity today...especially with the media, but even with other pilots thinking they know everything. I was a Flight Safety last week for some recurrent training and you wouldn’t believe some of the comments made by what we would hope to be educated pilots in and around that facility. You did a great job at explaining this so even people that really have no idea what you are talking about could somewhat understand. It literally gave me chills while I imagined myself in the left seat with some of the numbers you were throwing out here....unreal! Rest In Peace fellow airmen, I sure hope you didn’t die in vain and the industry thoroughly rectifies this situation....because if they don’t we will be hearing more reports such as this one, which was bone chilling. Thank you again for your post. Great job!
@blancolirio5 жыл бұрын
Thanks Dustin!
@jimpartin11445 жыл бұрын
Well done Juan. It’s tragic that the crew missed disconnecting the auto throttles and allowed the airspeed to run away. I read somewhere that MCAS also through the elevator feel, makes it more difficult for the crew to add nose up elevator by increasing the amount of pressure that it takes to pull the yoke back. If the crew had disconnected the auto throttles and kept the speed at 230-250 kts, they could have used the engine power to force the aircraft to pitch up and relieve pressure on the stabilizer to allow manual trimming of the stabilizer. It’s just a tragic situation that Boeing put these crews into.
@gordonrichardson29725 жыл бұрын
Precisely! Unfortunately reducing airspeed was probably not on their checklist, due to stall warnings.
@Voyager.25 жыл бұрын
Basically when the linked AoA sensor fails, the aircraft dives. No redundancy, no switch off button (for the MCAS only), no warning. Brilliant.
@ianhinson28295 жыл бұрын
You've summed it up nicely. Further to that though I would say that when redundancy detects that the primary sensor inputs are unreliable the dependent system should switch ITSELF off. But Boeing failed in two further ways additional to allowing MCAS to take control of the plane based on a faulty input: 1) not providing a clear indication to the pilots that MCAS had kicked in and was forcing the nose down, and 2) not providing a way to disable MCAS while still preserving motorised trim control on the yoke. Both of which you covered in your post.
@RockinRobbins135 жыл бұрын
@D Madd11 If you read the preliminary accident report and 737 trim system information Juan supplied above, you can see that three generations of pilots, all since 1967, have been required to memorize the steps to overcome an elevator trim overrun failure (MCAS is just one of the possible causes) by moving the elevator trim cutout switches to the "cutout" position, control the plane with yoke to a safe flying altitude, attitude and speed, THEN to manually trim the aircraft with the manual trim wheels. And most importantly, the memory procedure contains a final instruction not to return the elevator trim cutout switches back to the on position. This pilot disengaged the MCAS and automatic trim systems. He then failed to regain control of the plane, allowing it to pass 500 knots, way over Vmo, failing to slow the plane down to unload the trims so they could be manually adjusted after he followed his first ground school instruction before he stepped into a Cessna 172: FIRST FLY THE PLANE. Once you have control in a safe attitude, altitude and airspeed, THEN AND ONLY THEN troubleshoot peripheral problems. This pilot twiddled with trim controls when he should have been flying the plane. Then he switched the elevator trim cutout switch back to on, against the memory procedure he was required to fly by. It is as if a terrorist seized control of the plane attempting to dive it into the ground. The crew overpowered the terrorist, regaining command but not control of the plane. Next they decided it would be better to put the terrorist back into control, whereupon he immediately did what he set out to do to begin with: crashed the plane. Substitute MCAS for terrorist in the last paragraph. Now, who crashed the plane? Of course the proximate cause was the terrorist performed a controlled flight into terrain. But the actual cause was the pilot put the terrorist back in control. This is pilot error. Now, can Boeing increase the safety of the plane? Of course. ALL planes can be made safer. But in their position, with all the haters in the world after their blood, CAN they fix it? They probably will do so even though in the present climate of misinformation the news media will interpret it as admission that the plane was dangerous. A lesser corporation wouldn't change a thing, rightly claiming the plane is safe and admission of fault by unnecessarily improving systems doesn't keep any future pilot from crashing the plane, should he be sufficiently determined, but would expose Boeing to significant liability exposure. Isn't that the result of many, many of these witch hunts? In the name of aircraft safety, they actually make flying much less safe.
@robroilen44415 жыл бұрын
@@ianhinson2829 There is no need for an additional indication of an MCAS trim input, a competent pilot would most likely not get the aircraft into that configuration and an incompetent one will either already know the runaway trim procedure or just crash. The point being made about the tension on the jackscrew still stands whether or not you're trying to use the switches on the yoke or the wheels; you have to unload by pitching down if you want to adjust the stabilizer trim at such excessive airspeed.
@MarioBoyRoblox3605 жыл бұрын
@@robroilen4441 Pitch down at ~1000-3000 ft AGL?????
@robroilen44415 жыл бұрын
@@MarioBoyRoblox360 Yes. Not exactly a by-the-books maneuver and in this particular situation probably not a fantastic idea, but true to design either way. As mentioned, the MCAS system can only operate when flaps are up and autopilot is off, so there was in fact a configuration that could have saved the aircraft.
@BillKristjanson5 жыл бұрын
Damn! That's some powerful stuff! You've brought tears to my eyes... Those poor people didn't have a chance!!!
@gizmogoose.24865 жыл бұрын
_I like your informative and timely Avatar !!!_
@tomo00865 жыл бұрын
Star Gazer How? If they couldn’t manually trim?
@kkikke20035 жыл бұрын
Fact They tried to use AP while stick shaker on They never disengaged auto throttle They had one ir perhaps mire window
@kkikke20035 жыл бұрын
Of chance Apparently captain never heard of indonesia crash
@t_sixtyfivex_wing87875 жыл бұрын
@Sasha R trim manual control is very very slow response, the altitude and time was too low, 500 knt or 300 knt is not much different while altitude reduces several times by the MCAS nosing down, and how slow we can save the plane? its very very hard time.
@redj595 жыл бұрын
i recommend your videos to lots of people, people with no aviation experience, they learn a lot because you take the time and do a great job explaining the issue.thank you
@Santanadallas5 жыл бұрын
Thanks Juan- I forwarded your video to my brother who is a commercial pilot as well ( 767) and he thanked me and said you definitely know what you are talking about ! Not that I doubted you -but it motivates me to watch all your videos.
@blancolirio5 жыл бұрын
Thanks Randy!
@blipco55 жыл бұрын
Thank you Juan, I'm a grown man yet I watched your report with tears in my eyes. They were so close.
@blipco55 жыл бұрын
Kreemerz ...Yes fuckwit.
@algrayson89655 жыл бұрын
@@blipco5- Don't be so hard on a 10 year old troll.
@maxon16725 жыл бұрын
You have by far the best, most comprehensive review of each new piece of information we have access to, right after it’s released. I, and I am confident that many other people appreciate your videos on the MAX series 737 situation very much! In a sea of 2 minute long MSNBC/FOX/CNN garbage this is invaluable stuff. Thanks Juan!
@stefanstroh5 жыл бұрын
Thanks Juan most comprehensive explanation in this accident, how you explain Juam that that trottle wasent move in entire dive flight.why cut off trust to gain time.?
@marthavaughan46605 жыл бұрын
@@stefanstroh I think I know what you are asking--The engine thrust needed to be retarded to relieve pressure on the stabilizer, thereby giving the pilots an opportunity to pull the control yoke . they had plenty of speed already.
@duanequam77095 жыл бұрын
Once again you have made a very difficult issue understandable to the public and I am thankful for that. Great job.
@annemargaret55625 жыл бұрын
Thank you for explaining this so clearly. I'm (sadly!) not a pilot, but I'm a frequent flyer, I love aviation and I love to fly. It is helpful to hear someone experienced go through this initial report and make it easily understood. I am deeply saddened, as I'm sure we all are, about these two awful accidents, I am sure the pilots all did their absolute best to try to salvage what must have been a horrific situation. Thank you for taking the time to explain.
@motofan165 жыл бұрын
Watched all your briefs of this accident. Very clear! Many news anchors and so called analyzers have no clue about what they are talking about at all. Thanks as always. So close...
@ecomindedchoice5 жыл бұрын
The news media are professional at misleading the public, they see it as their jobs.
@johnvandenakker32455 жыл бұрын
Thankyou Juan . Very informative, and understandable to the lay person.
@Winnyf15 жыл бұрын
I shared this with CNN, I hope non aviation types listen your your comments, I'm sure many will not read or understand the investigation report. Thanks for making time to do this.
@davidscott59035 жыл бұрын
Once again you are way ahead of the regular news, and do a way better job of explaining things. Thank you.
@rixxy92045 жыл бұрын
ikr mainstream news is totally useless.
@jeff33884 жыл бұрын
lol regular news isn't used to making facts their priority
@samuelkmaina5 жыл бұрын
Thank you so much for sharing this info. I hope the families of the crew and passengers all hear and understand this. You've explained it so well. May they REST IN PEACE.
@jimh.52865 жыл бұрын
It sounds like maybe the air crew turned the electric trim system back on in desperation since they couldn't manually adjust the trim. Thanks for another great review.
@Bryan-Hensley5 жыл бұрын
I'd say panic was setting in by then
@kipaspusing25 жыл бұрын
The pilot only got around 30 second..to response for accident
@Kimberlyk125 жыл бұрын
That's what I thought. They couldn't get the manual trim to work, because of the force, and thought, try the electric trim and hope it reset
@rhamph5 жыл бұрын
Reducing engine power would definitely pitch the aircraft down. The 737-MAX is more sensitive to this than other 737s which is why (for the opposite situation, increasing engine power causing a pitch up) the MCAS system was added.
@WilliamJones-Halibut-vq1fs5 жыл бұрын
@@rhamph1 Reset Stabiliser Breakers, 2 Immediately Trim Up using trim switches thereby disabling MCAS, 3 Pull the breakers before MCAS can move the Stabiliser again. Its with the benefit of hindsight but they did have a slim chance.
@gmcjetpilot5 жыл бұрын
I've been in the industry for 30 years. What's being reported in this video is very comprehensive and complete. The reliability of older Gen 737's trim sys may have lulled Boeing & FAA into complacency. There's really nothing to add. Yeah.
@BlueZirnitra5 жыл бұрын
@WHITE DIAMOND You should stop shouting if you want people to read your comments.
@jamezh28225 жыл бұрын
@@BlueZirnitra if I had no answer for his very astute question I'd also go with being a grammar Nazi.
@jamesdelaney10665 жыл бұрын
Juan. Please get a patreon account so we can donate to help with this channel. You are amazing. Thank you so much. Keep them coming!
@birdwing985 жыл бұрын
Dig deeper. There is a way to donate to offset Juan's production cost; to help him invest in better cameras and upgrade editing software. Also, help him with upkeep on his Luscombe!
@flybyairplane35285 жыл бұрын
birdwing98 unfortunately, it’s NOT on this video update,. Cheers from NJ
@andysimms18025 жыл бұрын
A heartfelt report Juan. Hats off to you and all the aircrews who fly us safely around the world. Respect. PERIOD!
@jimmbbo5 жыл бұрын
"I was always afraid of dying. Always. It was my fear that made me learn everything I could about my airplane and my emergency equipment, and kept me flying respectful of my machine and always alert in the cockpit." Chuck Yeager As a retired airline pilot, simulator instructor and check airman who has given and solved countless trim runaway exercises, your explanations hit the nail on the head. Today's technology does not relieve pilots from heeding Gen. Yeager's words...
@jaminthomas5 жыл бұрын
But you can't learn what isn't told to you! MCAS was invisible to the pilots. Even after the Lion Air crash when the system was brought to light there is a lot of confusion on exactly how it works and this accident is clearly showing how powerful and insidious this system is. Competent and well trained pilots would have been able to deal with this issue IF they were made aware and trained to counteract a malfunctioning MCAS. However, Boeing did not want this to happen as this would mean expensive Level C or D simulator for the airlines, defeating a key selling point for the Max. This really shaking my confidence in the 737 Max forever because MCAS is such an integral part of the aircraft. I think the final solution to restore confidence is for the FAA to modify the certification of the Max to require the ability to turn off the MCAS fully and require training to handle that. This is going to be costly which Boeing will be responsible for but in the long run l think is the best solution.
@ecomindedchoice5 жыл бұрын
@@jaminthomas It would seem by this preliminary report that the pilots made the right choice by turning the MCAS system off but then lost control through over speeding the aircraft followed by multipel misguided attemps to recover without the benefit of situational awareness.
@iangill89845 жыл бұрын
@@ecomindedchoice My reading was that the pilots did the right things but had a couple of missing elements. Altitude and time. That gives you time to try other things and towards the end it was pretty desperate. Bjorn Fehrm runs through a detailed analysis on Leeham News. Like Juan he was a fighter pilot.
@ecomindedchoice5 жыл бұрын
@@iangill8984 The excess speed made the manual trim unusable. It was when they were unable to manually set the trim that they lost control of the airplane leading to the crash.
@MauroPanigada5 жыл бұрын
@@ecomindedchoice At this point we wonder why they kept such a high speed. Found themselves unable to trim manually, could it be speculated that they turned the stab trim cutoff switches back on in order to exploit the electrical trim for a moment, with the intention to turn it off as soon as the stabilizers were “lighter” to trim manually?
@donkoh57385 жыл бұрын
Thanks for keeping us all here posted, sir... thanks for your continued service.
@richardskingdom5 жыл бұрын
Your commentary on this issue is careful, thorough, crystal clear, free of hype and unbiased. I've seen nothing like it on the rest of the Internet. Keep up the excellent work.
@richardskingdom5 жыл бұрын
@@kradius2169 You are completely right to point that out. Based on the timeframe from conception to initial commercial flights I think it would be unfair to say the program was rushed. What was rushed was my comment. And in keeping with the well researched and careful nature of the original video I have removed the incorrect statements. I had a different point and worded my comment very poorly.
@stimproid5 жыл бұрын
@@richardskingdom You get 1 million internet points for integrity and strength of character my friend.
@547Rick5 жыл бұрын
Thanks Juan! I always wait to hear from you before I can form an opinion. Thanks again!
@sebastiannikkolas84975 жыл бұрын
I feel so sad, speechless. :( Thank you Juan for this accurate reprt. Godbless you.
@rayg90695 жыл бұрын
@@danhillman4523 The pilots did nothing wrong, there was nothing structurally wrong with the aircraft, those people were killed by a software bug that made it through how many levels of verification?
@joso55545 жыл бұрын
Ray G There is no software bug! The MCAS does exactly what it was supposed to do by design. There is a major design fault in terms of systems safety ( robustness to component malfunction and man-machine interface ).
@rayg90695 жыл бұрын
@@joso5554 You mean crash an aircraft? Because that's what it is capable of as proven by two accidents. There is not enough cross checking of the flight instruments by the automation systems to identify invalid signals, that's a software bug.
@noharrr52285 жыл бұрын
[non-aviation person here] Thank you for your clear, objective explanation of this event, without the limitations of news sound-bites. Your emphasis on how important simulator-training is for learning the *feel* of stiffness in the manual trim jack-screw mechanism in the cockpit, plus another video by the Airline Pilot's Association rep that Boeing's "training" on the 737-Max 8 consisted of "56 minutes on an iPad and you're good to go" made me want to scrrrream as an educator: you can't expect *anybody* to be prepared to deal with such a complex system in real anomalous conditions under those circumstances!! You can't even get a DRIVERS' LICENCE based on 56 minutes on an iPad, for a ground-transport vehicle operating (avg) under 100 kmph with (avg) 2 passengers. To learn that the physical redundancy of the angle-of-attack sensors had been designed OUT of the MCAS inputs makes no sense. Redundancy is an essential element in everything from packing for a camping trip to stage production. How NOT to include it in this fundamental input? Are we (finally, scarily) entering an era where video simulations are deemed enough of a substitute for reality, to skip the reality checks? Reality BITES. And it has no "reset / replay" button. I hope the entire top-heavy aircraft production industry is forced into end-to-end review. Current communications technology makes it possible for we, the passengers, to reconsider if our next flight is really essential, or if we'd rather stay home and invest the money in a quality land-based vacation instead.
@maubur5 жыл бұрын
Excellent job Juan. I would never have imagined that when designing an electric trim, it wouldn't be mandatory to have a motor and linkage system capable of overcoming aerodynamic forces within structural integrity boundaries. Also, I can't imagine why, after hitting the trim cutoff switches and leveling out at very high speeds, the over speed situation wasn't immediately addressed by backing out the throttles, thus reducing the forces the trim wasn't able to overcome. Hindsight is always 20/20 but...
@onehatmedia5 жыл бұрын
It's heart wrenching. As a software developer, I'm envisioning being one of the engineers on Boeing's team. Why did MCAS only read from one AOA sensor? It's a single-point-of-failure. I'm sure they're kicking themselves for that one.
@sietuuba5 жыл бұрын
My guess... higher-ups decreed that AoA anomalies shall be considered a low risk event (which did happen, one way or another, and by the rules meant they were allowed to get away with reading only one of the two sensors). That's regulatory capture for you and, in this case specifically, enabled by self-oversight and not funding the FAA at a level necessary for the work! Now consider what else has been neglected. FDA, EPA, you name it.
@yishakibrahim5 жыл бұрын
That is not the only surprising story. On the military aircraft (kc) the MCAS system exists - it reads from two AOA sensors and the pilot can disengage it. What is so fucking is that how boeing engineers ( i rather call them interns), striped the safety and fitted with no redundancy on the max!!!!!
@joso55545 жыл бұрын
yisjobTube can you bring some more info on the MCAS system on mil transports? when / on which type was it first introduced ? was it actually named MCAS ? was it mentioned in aircraft documentation ?
@WilliamJones-Halibut-vq1fs5 жыл бұрын
I suspect that it’s got to do the the architecture of the two ADC “air data computers” and the 50 year old system philosophy of B737. There are only two ADC not three. It’s not a triplicated fault tolerant system and relies on the crew identifying the faulty computer and instrument and manually switching over to the good side of the cockpit. The architecture may not have supported the programmer easily accessing data from both sensors. The sensors are connected to only 1 ADC each although the ADC cross connect. It’s also incompatible with the philosophy. I’m a PLC Programmer not an avionics expert but there is more to this than a simple bug or oversight. The sensor disagree alert was part of the display system I think not the ADCs. The software upgrade Boeing have produced has made the system failsafe but it’s not fault tolerant. You need minimum of 3 sensor and CPU for that
@sietuuba5 жыл бұрын
@@WilliamJones-Halibut-vq1fs Oh man, that makes total sense to me but I'm no expert on any of this - but it would fit perfectly into why there may have been a drive to rank the risk from an AoA indicator anomaly as low as they did. I forget the exact terminology, I only read the Seattle Times article once, but with a sensor failure and its repercussions ranked artificially low enough the regulations allowed them to implement the system the way they did... and the rest is history. Gaming the system to get the answer they preferred instead of taking on a more fundamental overhaul and the work, time and expense that would thus be necessary. Passengers are just a commodity, not customers for the higherups.
@annharris25085 жыл бұрын
Thanks Juan, we can count on you to give us up to date information that is poorly lacking from the MSM. We appreciate all you do. Keep up the great work, we are lucky to have you !
@RJ-sr5dv5 жыл бұрын
Juan, Great overview thanks. I am retired 737 pilot with time in the -300-400 & the -800. I have had trim malfunctions in a couple of different aircraft types over the years. Further we lost a crew at a regional carrier (ACA) back in the 90's who ignored trim inputs while on a ILS, compounded by power mismanagement. From the preliminary report that I saw it appears that this crew was so distracted they did not manage their speed. At about 1:45 into the flight they were in excess of the 340 Kts IAS. Thanks for your non - judgemental observations...
@Kosmonooit5 жыл бұрын
Yes it seems the high speed was the really crucial factor in this accident, the report says there was no change in the throttle inputs all the way to the tragic end, and there was no system at fault there. Due to the high speed the FO could not manually trim the aircraft. First thing you are taught (as a pilot of whatever type) in handling an emergency is FLY the airplane. Then deal with the emergency.
@johnnyboythepilot40985 жыл бұрын
@@Kosmonooit Maybe if they cut power and popped open the spoilers to slow their speed when the aircraft started to dive, maybe they could have had more time to recover the trim manually.
@davidwright71935 жыл бұрын
JohnnyBoythePilot That cuts a major force keeping the nose up coming from the engines.
@killz4money5 жыл бұрын
There is no way to be sure, and most likely they didn't have time to think about it (what with the highly intense workload of dealing with an out-of-trim aircraft at this altitude). But perhaps the nose-up moment coming from the high thrust setting (the reason MCAS was implemented in the first place) was of benefit to the crew. Although at some point that balance was likely skewed and the high airspeed put too much force on the vertical stabilizer for them to trim it back. In all of this I do not understand how such a critical system was designed to take input from one sensor only.
@Menelik.videos5 жыл бұрын
If they had throttled down, then the nose would have pitched down even further. On another note, am I wrong or did I see somewhere that the MCAS actually controlls the throttle input of the airplane as well?
@dand77725 жыл бұрын
BEST EXPLANATION OF ANY NEWS ORGANIZATION. GREAT JOB JUAN.
@towerrunner4965 жыл бұрын
One piece that I haven't seen Juan talk about, that may not be known by many about the current MCAS configuration. At present the MCAS uses the data from one AOA vane, pretty much we all know that, correct? But what I haven't seen mentioned is, the program for the MCAS switches to the other AOA vane, each flight cycle. That is, on one flight it will use the left vane, on the next flight it will use the right vane, and again back to the left vane the next fight cycle, and so on, It does not use the same vane twice. . In the Lion AIr accident the day before, the inoperative vane, caused the nose down, but the jump-seating pilot realized what was happening, while the crew was trying to regain control of the aircraft, and they were alerted and responded, resulting in a recovery of flight control. What happened though when it landed, is the MCAS (with a completed flight cycle) switched to the good AOA vane. When Lion AIr maintenance ran test on the aircraft, apparently the MCAS system was included in the test they ran, per Boeing's instructions in their maintenance manual. It tested good, not able to duplicate. The computer controlling MCAS, considered this a flight cycle, and switched back to the inoperative AOA vane. The next day, soon after the Lion AIr fight climbed out after departure, they started having the same problems the crew did the day before, unfortunately resulting in the lose of aircraft and all on board....Further investigation of the the test Lion AIr Maintenance did, and Boeing's procedures for that test will have , and I am sure are being looked into. Had their maintenance known to test the system twice, might have broke the chain of events that lead to this tragic event!
@nobytes25 жыл бұрын
MCAS the system from hell. So I assume maintenance manual is also at fault.
@osd99335 жыл бұрын
The MCAS is badly designed as it lacks the redundancy of using two AOA sensors during a flight. Safety demands that but somehow what was obviously necessary was not implemented. Why?
@nobytes25 жыл бұрын
@@osakarose5612 I've never worked in avionics but I work in software in the oil industry every sensor throws an alarm for faulty readings. So it will be in the alarm log, and also historic data. I've seen systems that use 6 encoders for redundancy and if one encoder disagrees is automatically taken out of system. Surely it has to be more advanced in planes? As an ex maintenance myself I would have tested both readings from. both AoA sensors.
@MikeCris5 жыл бұрын
WTF? This is the first I've heard of this.
@gordonrichardson29725 жыл бұрын
Tower Runner Good points. The MCAS AOA alternates between flights, except when powered off during maintenance, after which it always resets to captain side.
@HjFUN15 жыл бұрын
"At 05:40:35, the First-Officer called out 'stab trim cut-out' two times. Captain agreed and FirstOfficer confirmed stab trim cut-out. " When I read that this morning, I was deeply affected, since this corroborates what you have said and the news headlines saying the pilots had done the correct procedure.
@MauroPanigada5 жыл бұрын
The headlines now say so because of this preliminary report.
@agentbb0075 жыл бұрын
15:20 followed the procedure initially but when they couldn’t manually trim they turned it back on, that was the fatal mistake.
@MauroPanigada5 жыл бұрын
@@agentbb007 This makes me think. There are two switches, "main elect" and "auto pilot". Is that possible that the mistakes was to believe that they could turn on just the "main elect" and this would have prevented automated "pilots" to intervene? In this case it would have been a misunderstanding of the systems which can command the stabilizers - or just a desperate last hope. Also, this makes me think of another design flaw in this MCAS: the stab trim autopilot switch in cutout position should be sufficient to disable it. This would allow electric manual trimming, which is the only hope in certain circumstances. And of course, the runaway stabilizer check list would change so that you put in cutout also the "main elect" only if the runaway event continues despite having the autopilot in cutout.
@stephen46xre865 жыл бұрын
The pilots on the Ethopian flight had no chance to recover since they hadn't the luxury of height to trim the aircraft manually to a horizontal position of the stabilisers. The electric trim was likely turned on again since they were not able to adjust the trim manually.
@algrayson89655 жыл бұрын
Stephen, >the horizontal stabilizer trim jackscrew motor has no mechanical connection to the trim wheels on the control console. By turning a wheel with the hand the motor shaft or the jackscrew nut are not turned mechanically. "Manual" can mean only that the computer is not involved.< Part between > and < is wrong. I misinterpreted my source. It does look bad that by turning the MCAS off the system doesn't revert to input from the control panel wheel.
@Kosmonooit5 жыл бұрын
@@algrayson8965 What has been said is those manual trim wheels are mechanically linked by cable to the jack screw, no hydraulics or electrics involved. They couldn't manually trim the aircraft because it was going so fast. One could say the could have momentarily enabled the electric trim to trim up in stabs and before the MCAS did its thing but so easy to say from the sidelines right now.
@dwilliams20685 жыл бұрын
*@Al Grayson* A minor point but the screw is the only part of that stabilizer trim system turns. The nut is linked, in some way, to the front of the stabilizer. You do say "motor shaft or the jackscrew nut" but I just wanted to add a bit of clarification. You do say, in your follow-up comment that the mechanical trim wheels in the cockpit are manual all the way, with cables.
@paulavery3665 жыл бұрын
@@algrayson8965 - Mentour has described how the trim wheels are mechanically connected to the jackcrew motor by an old-fashioned cable drum system. At the airspeeds recorded, the trim forces required would have been beyond the capabilities of the motors or the handwheels.
@algrayson89655 жыл бұрын
@@paulavery366 - Thanks. I will go back and find my erroneous comment and add your correction.
@BradGryphonn5 жыл бұрын
Mate, I'm a minute in and I can see that this has cut you deep. Man hugs from a long time Aussie follower.
@blancolirio5 жыл бұрын
Thanks Brad. Just gutted me when I read that report.
@dwainsellers64535 жыл бұрын
Best explanation that could be provided, thank you Mr Brown, very informative in a way that most of us can understand, thank you.
@mainbeachbob5 жыл бұрын
Thank you for all your work. The best thing on KZfaq and the details are clearly explained. Keep going.
@RobDeHaven5 жыл бұрын
I read through the report after watching the video. The sense of urgency towards the end of the flight is ever apparent. It is like being in the cockpit on those final few moments. I couldn't imagine listening to the cockpit voice recording. The people that do that job have a difficult task and I wouldn't want those memories floating around in my brain. Juan, I'd be curious to hear your take on how your approach would be if you were to be a captain of the 737 Max aircraft once it gets clearance to fly again. How much technical information is released by Boeing on exactly how this system works and what it takes to take it offline. The report doesn't mention either pilots switching the trim cut out switches back to the on position and hopefully that is released in the final report. I would personally want to know everything about those automated systems and how to disable them in the event of an emergency. For example, I know it would be counterintuitive but adding 15 degrees of flaps with the autopilot off would have removed MCAS from the equation. Against the standard training and maybe that isn't something even possible at those speeds. Heartbreaking for everyone that lost a loved one. Gut wrenching for Boeing engineers.
@phillee28145 жыл бұрын
@@kradius2169 Thet clearly did exactly that, or they wouldn't have known (as stated) that manul trim was ineffective.
@eduardoletti55375 жыл бұрын
The other system Juan refers to in addition to the MCAS is the STS, or Speed Trim System. The speed trim system provides automatic trim inputs during manual flight. The system trims the aircraft using autopilot trim. It will most frequently be observed in operation during take-off and go-arounds. Conditions for speed trim operations are listed below: 1) Flaps not up (B737-300 & 500), 2) Flaps Up or Down (B737-400 and B737-NG), 3) Airspeed 100-300 KIAS (B737-3/4/5) or 100 KIAS-M0.50 (B737-NG), 4) 10 Seconds after lift Ott, 5) 5 seconds following release of trim switches, 6) N1 above 60%, 7) Autopilot not engaged and 8) sensing of trim requirements.
@nobytes25 жыл бұрын
Juan I appreciate you taking the time to acknowledge the FO correct actions, media was quick to blame him due to his 200hrs.
@dawnchattin59355 жыл бұрын
Media misinformation, probably from Boeing, to deflect the real cause, Boeing and FAA. the pilots were true heroes. May they rest in peace.
@Paul1958R5 жыл бұрын
Juan, Thank you for this video, your reporting, and expertise. Looking forward to your updates. God bless Paul
@daveluttinen25475 жыл бұрын
Your excellent description gave me sweaty palms - not from the description of the 737-MAX flight so much as recollection of my instrument check ride and unusual attitude recovery under the hood. You look down and everything is perfect and all hell breaks loose. These pilots did a yeoman's job considering the circumstances, but I think Boeing best settle out of court on this one. RIP to those passengers and crew.
@fredasbury52715 жыл бұрын
Excellent evaluation and explanation of this problem. It is important for the industry to become transparent relating to the truth of why accidents occur. I am a retired A&P mechanic and I find myself very frustrated with the legal double talk that all the involved entities start throwing around confusing the public which throws the resolution of the incident into years of wrangling while an immediate solution and conclusion to the incident should happen. Very frustrating.
@karlfair5 жыл бұрын
Juan, you have explained this better than any other other source, I have found. Thank you, Sir
@riitaalin5 жыл бұрын
Excellent report. Thank you for explaining everything. I really enjoy your channel. Great Report Again.
@KhaledTheSaudiHawkII5 жыл бұрын
I didnt understand a word of what you said in this video but your demeanor and your facial expressions gave me a vivid enough picture of what those pilots and passengers went through and that made my heart break.
@blancolirio5 жыл бұрын
Thanks Don.
@herseem5 жыл бұрын
Thank you for your illuminating and careful analysis and explanations. As both a (former) professional programmer and someone who has studied disasters in man-made systems for decades, a key element of this is that it's a case of multiple complex systems interacting in ways that weren't fully anticipated. 'Fully anticipated' needs to include reasonable-to-expect faults occurring. It's similar in some ways to the introduction of both autoresponders in email systems (so you can let people know you are away when email arrives), and email distribution lists.If you get two people in the same group setting up autoresponders, and someone sends a group email, both autoresponders will reply, and (depending on configuration) automatically sending a reply to the group email, that is then automatically redistributed to each other member of the group. If the email would also be sent back to the person who originated it, then only a single person setting up an autoresponder was required for this to happen. This creates a runaway reaction until mailboxes are full. Most mail systems that I'm aware of now have things to detect this to prevent it happening.
@railroadjim5 жыл бұрын
Terrific analysis of the event Juan! Your point of view is excellent, being one of the few people who actually have enough insight to understand and explain the situation. Thank you again for sharing this with us. The aircraft speed and lack of altitude seemed to really play against their odds. Sad.
@johnjarrell30685 жыл бұрын
Former low-time, single engine land pilot. Wonderful presentation. Please keep it up! Thx!
@blampa5 жыл бұрын
Thanks Juan, you are the ONLY trustworthy source in these matters. You don’t dramatise or speculate; you tell the facts and explain them well. Does your company 777 sims have the hacks such as the runway pause to get to 10000 feet in about 3 seconds? The one we have is for the 300er.
@catherinenelson41625 жыл бұрын
Bless the pilots for trying so hard to save that flight, Juan. On a personal note, one of the women on that Etheopian flight was my spiritual sister, a member of my Christian Religion, from a Muslim country where we operate under ban and some persecution. My prayers for her family as well as for the families of every one on that plane. Thank you for this update. You did well, especially knowing that other pilots are your " brothers" in the air, even if you didn't know them.
@Kimberlyk125 жыл бұрын
So sad for her family. I'm so happy, though, that they will see her again
@kingdomcome79545 жыл бұрын
An Which Muslim Country would that be?? Lol, Stay in Your Basement An Stop Talking Things if you have No clue about.. that’s The Problem With Kids Today..Just Cause you have Internet Doesn’t Mean You Know What’s Going On Around the world.
@nicoladavies33915 жыл бұрын
Kreemerz Nothing hateful in Warsame’s comment about a particular religion. I have no clue why the original commenter would even think it relevant to this topic.
@albedo0point395 жыл бұрын
What I find unbelievable is how the AOA reading seemed to be not just slightly wrong, but completely outside the bounds of expected values. Even monitoring just one sensor, highly critical systems often only respond to inputs that pass a ‘sanity check’. Should MCAS have seen the sensor jump to 70 degrees in such a short time and rejected it as an erroneous reading? Amazing that it reacted to it.
@philoso3775 жыл бұрын
The aoa vane flap like a nation flag - plus and minus 14-deg or more and averaged to plus (pitch up). Either intermittent electronic problem or the vane had service ribbon attached and remain attached after maintenance until crash.
@Kosmonooit5 жыл бұрын
I think this is where Boeing is going to be held to account, having such a system only rely on one sensor. Did they (the dev team) think through every eventuality? Prophets of Autonomous Vehicles take note.
@MartinVisser5 жыл бұрын
@@philoso377 while you can smooth the values electronically ( through low pass filters) or arithmetically ( via averaging) you would imagine simple oil or other viscous fluids would prevent a lot erroneous measurements due to that flapping
@vladstep32475 жыл бұрын
Martin Visser kats
@vladstep32475 жыл бұрын
YK Chan by u b17 by see see st bu k v k
@llegner5 жыл бұрын
You finally made sense of a terrible situation exasperated by ridiculous airspeed
@robertoler37955 жыл бұрын
FAirly reasonable Captain. the only thing I disagree with is that the crew was no where near saving the plane. it boils down to a single point cause of an equipment failure mishandled. The crew failed in three ways 1) engaging autoflight (LNAV AND VNAV in particular) with a known equipment malfunction affecting control of flight 2) failure to attain either flaps down or up airspeed unreliable configuration, 3) immediate removal of stab trim power through the stab trim cutout switches. had those things been done in the first minute, they would still be here. the horizontal stab movement (uncommanded) was due to air loads on the stab as the airspeed increased...the pitch issue was the nose trying to maintain "trim speed" as the airplane accelerated. Robert G. Oler Capt and USN test pilot (and former Boeing Test pilot)
@pasphilc79945 жыл бұрын
I respect ur opinion sir, but are u trying to blame the pilots?
@rickyricardo99185 жыл бұрын
Good observations though it does seem to suggest the crew "failed" to deal correctly with the trouble presented therefore the burden of responsibility for the loss lies with them. I'd suggest... - the allotted 1-minute of elapsed time to troubleshoot and diagnose a fault that in it's early moments was not severe seems rather an unfair burden to place on pilots. Passenger's want a robust a/c where the crew may achieve a letter "D" grade on this type of test and not die. - commercial aircraft should be designed to be fundamentally stable in flight, and bad characteristics not allowed for the sake of fuel economy then masked via slipshod f/c programming. - " a single point " failure should not have been designed to create danger to the degree this system has. Two new a/c lost in a short period of time as a result of what appears to be originating from the same "single point" component failure smacks of a design fault(s). Passengers don't want to fly in a/c where the crew is expected to be lucky or at the pinnacle of their game otherwise dead.
@gordonrichardson29725 жыл бұрын
pasphil c I think everyone agrees that the pilots made some mistakes. However they did not cause the accident, that was triggered by MCAS. Trying to attribute blame does not help anyone.
@robertoler37955 жыл бұрын
@@pasphilc7994 the job of the pilot in command is to be able to deal with any and all systems malfunctions. a failure of the AOA in some form or fashion is no different then say a failure of System A or B hydraulics or an engine failure or whatever... the automation is a little more tricky to deal with but yes the pilots made error after error in dealing with an static sitution if on stick shaker (which was known to be in error) the pilots had followed standard training procedures and 1) not connected the automation including disconnecting A/t 2) stablized the plane at some altitude in the take off configuration ie flaps 1 or 5, (ie the airspeed unreliable checklist) 3) possibly taken the stab trim cutout switches to off (but as long as teh flaps are down this was not needed) and 4 returned to Addis...they would be alive. its not rocket science...its airmanship
@robertoler37955 жыл бұрын
@@gordonrichardson2972 no they caused the accident. in accident investigation parlance the failure of the AOA in some manner was the trigger event. they then proceeded to handle the plane and its systems badly after that. all pilots and the PIC must be able to deal with systems malfunctions and not lose the plane
@billthetraveler515 жыл бұрын
How horrifying to imagine the focus that the crew was using to fight a dumb system. It is not surprising that the crew could not notice the outrageous airspeed. I don't understand why MCAS sensors that disagreed (AOA) wouldn't, by default, shut down the MCAS. If left equals right, then engage MCAS. If left not equals right then disengage MCAS. There. A truck driver just wrote a software correction. Thank you for a great report. Fly safe.
@nobytes25 жыл бұрын
I read that boeing made MCAS a certain level below hazardous to avoid making it redundant and to avoid having the plane be another certificate level to avoid millions in re training and certification. I think a 10yo with a raspberry pi could have designed a better system surely boeing engineers could too, but I believe greed at the top got the better of them. Also they were pressured by airlines to deliver fast or else go with airbus.
@davetaylor90575 жыл бұрын
According to previous reports the MCAS system only takes input from one AOA sensor. Since it doesn't 'see' the other sensor MCAS cannot detect if the AOA sensor data differs. There is an option on the 737 Max to have an on-screen indicator display a warning if the AOA sensors disagree but not all 737 Max buyers have taken the option.
@jeevansingh77725 жыл бұрын
@@davetaylor9057 An option by Boeing to buy this? Dam. Just the thought of selling this as a frill item sucks. It's all about profit maximizing by Boeing. Lives don't matter.
@Thephilpw995 жыл бұрын
Not only that, the manual system failed too. The trim wheels turned out to be useless in an emergency situation, which they were supposed to be used in. MCAS system failed, AOA sensor failed, and backup manual wheel failed too. How did Boeing's planes got certified for so many years?
@joso55545 жыл бұрын
Philip W No aircraft is expected to prevent a single failure. Safety must ensure that no single failure (unless its probability is extremely remote, which no electric/electronic component has) can endanger the flight. This is a matter of design choices, such as redundant cross-checking architectures etc. An AOA sensor, like any component, must be allowed to fail without endangering the flight. The MCAS system did not fail, it did exactly what it was (poorly) designed to do. Here we have a single failure causing a fatal accident, and the blame is on the overall design (especially MCAS design), not on the AOA sensor which noone should expect to be perfect.
@gungadinn5 жыл бұрын
Juan, high aeroloading on the stabilizer of a 737 would require BOTH hand wheels to be operated, not just a single wheel handle. Mentour Pilot showed this on one of his recent videos.
@JoeLinux20005 жыл бұрын
The location of the wheels make them awkward to crank particularly if there is any significant load.
@gungadinn5 жыл бұрын
Internet Privacy Advocate + I’ll partially agree with you on your statement. If you’re like 90% of the world, being a left handed person is usually an impediment. However in the case of the manual trim control wheels, being left handed as the co-pilot would help. The spring loaded handles are 180 degree opposed making manual operation like operating a two man saw. You’ve got to work together. There is no ideal location for the trim wheels that would allow for manual operation.
@eduardoletti55375 жыл бұрын
Not really. What is not readily apparent to the crews, is the fact that the manual handles of the trim wheels are offset 180 degrees from each other, (just like the pedals on a bicycle) strategically placed this way, so if necessary, both crew members can exert maximum cranking force on each respective handle to get the horizontal stabilizer moving in the desired direction, in this case, nose up. I have done the exercised described by Juan many times in the B737 simulator sessions as part of our training profiles at Varig Brazilian Airlines. Flying at 420 knots close to the ground, both pilots of Ethiopian flight 302 would have to exert considerable force on the trim wheels to get it move out of the binding situation described. The crew got distracted with the flight control problem and never reduced the thrust of the engines. This compounded the situation.
@mungewell5 жыл бұрын
Given that the stabilizer was so far out of trim, I assume Pilot was applying significant pressure to the yoke whilst the Co-Pilot attempted (and failed) to manually adjust. Re-engaging the motors to adjust the trim must have been an act of desperation, and Dis-engaging them a 2nd time appears to have been overlooked before MCAS 'corrected' once again. From the descriptions given it is not clear whether the motor for the jack screw is directly attached to it and thus the wheels in cockpit are turned via the attaching wires/cables, or whether the motor is attached to the cockpit end. Seems to me (arm-chair mechanic) that ability to manually adjust should have possible in all situations, regardless of aeroloading. Is the nut a regular threaded part, or a 'ball screw'?
@eduardoletti55375 жыл бұрын
@@mungewell The B737 Max has one trim motor attached to the stabilizer trim jackscrew located in the tail cone of the aircraft. After the trim motor is disabled by the Stab Trim Cut Out switches in the OFF position, the crew can manually position the stabilizer trim via the cockpit trim wheels in the cockpit which are mechanically linked through cables to the stabilizer trim drum in the back. The crew of ET 302 was facing extreme aerodynamic loads in the horizontal stabilizer, as the aircraft was allowed to accelerate well beyond its maximum certificated airspeed of 340 knots. At one point the airspeed is recorded at 480 knots!! This might have given the notion to the crew that the manual trim was also not working, prompting them, we suppose in an act of desperation, to re-engage the trim motor which enabled MCAS again, dooming the flight. The Ethiopian preliminary report is not complete. The FDR and CVR readouts must be superimposed in time, so investigators get a full picture of what was done and said inside the cockpit. We don't have the superimposing right now.
@jimmbbo5 жыл бұрын
Accidents are a series of events leading to a catastrophe. If any one of the events does not occur, the crash could be averted... IMO the events that lead to this disaster were * Unreliable/failed AOA system activated the MCAS * MCAS drove the nose down uncommanded by the crew * The crew attempted to cure the problem using brute force and yoke trim switches * The MCAS' intermittent operation masked the effectiveness of their efforts to regain control * Autothrottles remained engaged at full power for the duration * Crew belatedly conducted the runaway trim drill by activating stabilizer cutout switches * Crew reengaged the stabilizer trim system for reasons unknown * Increasing airspeed made it extremely difficult to manually trim the airplane * Inadequate altitude for any alternate efforts to regain control to succeed
@abrahamaddam53875 жыл бұрын
Thank so much for your honest and impartial assessments. I hope the N.Y. Times people will have time to watch this video.
@christopherbuilder53545 жыл бұрын
Thanks 🙏 for keeping us all informed!
@knunyabeasewhacks87445 жыл бұрын
Juan thanks again for the great reporting.
@timwildey79745 жыл бұрын
Sounds like the pilots did everything within their knowledge base and experience to control the aircraft.
@jamesmurray39485 жыл бұрын
Except control airspeed with the thrust levers.
@spacecadet355 жыл бұрын
@@jamesmurray3948 - But they needed the airspeed to maintain lift.
@algrayson89655 жыл бұрын
@@spacecadet35- Not at 350-400-450-500 kts they didn't. Not until nearing cruising altitude (30-40,000') is higher speed needed for adequate lift. The speed limit below 10,000' is 250 kts.
@spacecadet355 жыл бұрын
@@algrayson8965 - My response is simple. Even at nearly full throttle (thanks to MCAS) they could not generate enough lift to stay in the air. Lift is generated by Bernoulli Effect ( determined by using the Napier-Stokes equations) AND angle of attack (this is why aircraft can fly upside down.) If they cannot generate lift from Angle of Attack due to the trim issues, then the only other source of lift is by increasing the Bernoulli effect. This is achieved by higher airspeed.
@spacecadet355 жыл бұрын
@@algrayson8965 - It maybe, but when your only other option is crashing into the ground, pilots have a strange habit of prioritising problems. In a stall or sink your normal solutions are a) lower the nose and b) increase airspeed. Due to altitude a) is out, so what other solutions can you offer the pilot other than keeping airspeed up?
@More-Space-In-Ear5 жыл бұрын
Thank you Juan, it’s a lot easier to understand what happened when we have someone with such knowledge and understanding...much appreciated...rip for those who passed away. 😔
@waareagle36915 жыл бұрын
Unfortunately, the flightcrew appeared to miss an item on the "runaway trim" checklist that proved to be fatal... they didn't disengage the auto-throttles. The autopilot was in FLC vertical mode when the AP was disengaged... so the throttles were set at Climb power the whole time. While the crew was distracted by the trim issues created by the MCAS, the airplane was constantly accelerating. By the time the clacker activated, the crew must have been too overwhelmed to realize that the throttles needed to be pulled back. Had they disengaged the AT instead of reactivating the electric trim, they would probably still be alive. They were so close to resolving the issue; but once they shot past Vmo, it was probably unrecoverable.
@lehos245 жыл бұрын
I think you are very close to the truth. The pilots probably didn't think about airspeed or perhaps they thought that the airspeed indicator is also wrong. Their lack of training caused them to panic and to crash the plane.
@michaelstuart98585 жыл бұрын
I flew 737-100 -200 and -300 airplanes. I currently teach 737-800 (NG) to young newly minted ATP candidates to various Airlines. ‘‘This was a very good anaylisis of this MCAS system. The “single input” data from only one AOA vane is a fundamental flaw...one that was “optionally” fixable by an $85,000 “ala carte” ads-on from Boeing to include DUAL AOA input, and comparator indications in the flight deck. Something MY airline ordered. IMHO ....after 42 years in the flight deck, and several years in post airline training....this will come down to an inadequate explanation by Boeing, and subsequent lack of training of this system. All...IMHO...to compete with Airbus, based on the “Common Type Rating” mentality endorsed and approved by FAA at the insistence of the airlines witch order these airplanes. It is remarkable to say the least, that an airplane I few ( -100, -200, -300 ) could make me legal to fly a MAX with superficial “differences” ..... and nothing more....is not only contimplated, but exercised by airline training departments worldwide. VERY SAD....gut wrenching....and an inexcusable “chumminess” between manufacturer, airlines, and the FAA.
@joso55545 жыл бұрын
Michael Stuart Even between a 737-100 and 800 NG, beyond the handling characteristics, the differences are so huge that I cannot understand that a common type rating is possible...
@osd99335 жыл бұрын
Michael Stuart Your comments hit the heart of the problem.
@skyking13285 жыл бұрын
Thank You Juan ! Really appreciate your comments and continue to follow you. I will share this video with my USN flight crews. Also, really like that Stinson aircraft. It really looks Cherried out. P.S. You moved me over to Rice Farmers TV, and I'm really enjoying that also. Have a nice day ! //Rich/Fallon, NV
@md9295 жыл бұрын
Juan, I was a mechanic for United. I left when it got really bad after 9/11. I still follow aviation because it's in my blood. When Lion Air crash happened, I knew the MCAS was troublesome and buggy after doing some research. I'm an appliance and hvac tech now and I've seen control boards that react a certain way after a fault and when I looked at the service manual it's not covered. That means the manufacturer didn't see it coming. That's the same thing with the Boeing MCAS. I go into employee group blog and I told people not to go on the Max because it's buggy right after the Ethiopian Airline crash and I was scolded big time and thinks I'm just an alarmist. The majority thinks the foreign carriers pilots don't know what they are doing and didn't follow Boeing's procedure and that United's Pilots are one of the best trained in the world. I countered by saying, those four Pilots knew what they are doing and in fact countered MCAS but MCAS kept wanting to nosedive the airplane even after turning it off. I told them that Boeing put out a bulletin to follow after the Lion Air crash and the Ethiopian Airlines Pilots followed it but the MCAS kept wanting to nosedive the airplane. That's what I said after the Ethiopian Airlines crash. I knew they followed procedures. Why wouldn't they after a Lion Air incident and Boeing put out a bulletin to follow after that crash? Crew blaming, just because they're from the other part of the world, from Boeing and Americans who thinks they are the only smart people in the world are stupid and uncalled for.
@dave-in-nj93935 жыл бұрын
Damn fine explanation. A bit painful to listen to but knowing this can save the lives of every soul on board.
@Mark130919615 жыл бұрын
This
@jeff97235 жыл бұрын
I'm amazed that the system does not have the ability to determine inaccurate data from a sensor. How is there not layers of redundancy built in? I've been an auto tech for nearly 25years and vehicles have the ability to diagnose a bad input from a sensor and essentially ignore it. It will disable the affected system or rely on input from other sensors to determine the proper output.
@WilliamJones-Halibut-vq1fs5 жыл бұрын
Aerospace have fallen behind. They assume they are state of the art and space Age, in fact other industries and people of actually moved ahead of them.
@patdaly57695 жыл бұрын
Same here, what really blows me away is each and every cheap smartphone has a pretty accurate level sensor incorporated into it, why can't they incorporate this very robust ( compared to what they have ) sensor as a check. To me, it boggles the mind.
@TactileCoder5 жыл бұрын
@@stargazer7644 you don't. You show a warning and disable it altogether. That's the issue here. Do you understand the fiasco now?
@cruisertechgt5 жыл бұрын
This is why Airbus has 3 sensors ...u need 3 to determine which is right based on the average of the other 2 matching
@msears1015 жыл бұрын
@@stargazer7644 The coding logic would be that if AOA1 does not agree with AOA2, use NEITHER and MCAS will be deactivated. MCAS is NOT a critical system.
@joe2mercs5 жыл бұрын
This is great blow by blow account. I am not a pilot but I was struck by how rapidly events took place. Although the flight commenced at 5:38, wheels up happened at 5:38:39. If the clock starts running at wheels up the events seem to snowball all the more rapidly. Read the following, there is a sobering conclusion at the end. 0 Wheels up 6 AoA conflict...stick shaker activated on pilots yoke indicating imminent stall condition 21 “Command”....captain tries to engage autopilot. Electric trim is at 5.6 Maybe the captain has figured out AoA issue and wants to remove contribution from both AoA sensors as a safety measure 43. Autopilot successfully engages 66. “Flaps up” 67. Flaps begin to move 76 Autopilot disengages While flaps deployed or autopilot engaged the plane is safe from the attentions of MCAS 80. MCAS starts to trim down from 4.6 89. MCAS has now trimmed to 2.1 90. “DONT SINK” warning 92. Pilots electric trim up and also pull back on yoke 94. MCAS re-engages to trim down 103. MCAS has now trimmed to 0.4 “DONT SINK” warning Pilots electric trim up to 2.3 116. “Stabiliser cut out! Stabiliser cut out” Stabiliser cut out switch is engagedo 121. MCAS tries to trim the nose down BUT it is cut out of the loop because of the stabiliser cut out switch being engaged. 151. Air speed ‘clacker’ sounds VMO 177. “Is trim functional?” captain asks 185. “Not working” first officer replies after trying the manual trim wheels Not being able to overcome the force on the jack screw using manual trim wheels it seems likely that the stabiliser cut out switch was switched back to provide electrical power to the electric trim up motor 251. Pilots electric trim ups 2.1 - 2.3 260. MCAS engages to trim nose down 265. MCAS has now trimmed down to 1.0 Plane pitches sharply down so that pilots become weightless for a few seconds 283. Impact with ground The sobering observation is that it has probably taken you longer to read the above list than flight ET302 was in the air. Keeping the faulty AoA sensor inputs out of the flight control loop was essential, but once back in the loop (flaps up AND autopilot disengaged AND stabiliser ON) MCAS finally took flight control away from the pilots.
@Menelik.videos5 жыл бұрын
Nicely done sir.
@yvetinaash89975 жыл бұрын
Hy
@syfyrytr16525 жыл бұрын
Technical description of ROBOT horror story. It was hard to stand listening to the dramatic last moments of these pilots. Thank you, sir for your explanation to us laypersons.
@liveyourbestlife15135 жыл бұрын
MCAS is insidious. It's amazing to me that they designed a plane with a single point of failure: a AOA sensor. We have known for 50 years that single points of failure are unacceptable. Why would Boeing have designed such a fragile system?
@JohnnyMotel995 жыл бұрын
Boeing didn't consider it a critical safety system. Dual AoA inputs were an extra cost option.
@miroslavszabo37835 жыл бұрын
The problem is, that they were lazy. They should have designed a whole new plane at some point, but they were not bothered and fitted an old one with unsuitable engines. And, they ended up with an unstable airplane which needed an electronic system to keep the unstability at bay, which they designed cheaply because of greed. They forgot about the rule, that unstable jet aircraft should have ejection seats. That is why unstable aircraft are called fighters. And the 737 is not one.
@bradjohnson1695 жыл бұрын
...And, the MCAS override/malfunction/wrong information warning system was an $80,00 option! Cheap bastards Boeing. I understand the Ethiopian and Lion Air did not have this feature.
@prgaviation5 жыл бұрын
@@bradjohnson169 there is no MCAS information warning system, only AOA indicator and AOD disagree options, MCAS can be turned off easily by hitting the STAB TRIM cutout switches
@bradjohnson1695 жыл бұрын
Sorry if I am wrong , then what does this mean? www.geekwire.com/2019/report-optional-safety-features-boeings-737-max-jets-will-offered-free/
@Halli505 жыл бұрын
Excellent description of the additional factors involved, how the mechanical load on the jackscrew makes it difficult or impossible to trim Manually. Mentour Pilot did a video simulating a runaway trim in the simulator - and it took BOTH pilots cranking the trim handles to recover.
@michaelpruski22815 жыл бұрын
.....and yet Mentour Pilot has acknowledged his full confidence in MAX. Go figure.
@Halli505 жыл бұрын
@@michaelpruski2281, I believe Mentour Pilot was saying that he would have full confidence in the MAX once the idiotic initial MCAS implementation has been fixed, e.g. by using BOTH AOA sensors before activating, by limiting MCAS authority and maximum trim travel as well as issuing reliable warnings when MCAS activates. Boeing has a decades-long reputation for designing safe and reliable aircraft, and they WILL eventually regain that now-in-tatters reputation by leaving safety and quality issues to the engineers, not management, but the cost will be great.
@michaelpruski22815 жыл бұрын
@@Halli50 Indeed. You are correct regarding Mentour Pilot statement! Thank you. Regarding Boeing.... 350 people are gone and they wont be coming back.
@N8844H5 жыл бұрын
Let's not forget that the captain also had two throttles to use, and leaving them pushed up at a high power setting while fighting nose-down trim and with an overspeed warning in his ears was making everything worse. The crew didn't have altitude to trade to relieve trim force. It did have throttles to use to slow them down, and that (although a tough thing to do when near terrain) would have given them a bit more time to manually retrim and work the problem.
@eudofia5 жыл бұрын
@Robin. Before the preliminary report, the speculation was the crew maybe did not cut off the electric trim, thus disabling the MCAS. Now that the report is out, fingers are now pointing to the throttle situation. Was that the cause of the crash? The answer is no. Would reducing airspeed could have helped with the manual trim? The answer is maybe. Even at 250knots and nose down, the forces on the stabilizer would have still been too great to overcome with the manual trim wheels. Or maybe they could have if the plane had more altitude, a luxury they did not have.
@JohnBare7475 жыл бұрын
Thanks for the clear explanation Juan. The MCAS system is kind of turning out to be much like the Terminator, Relentless!
@neuromancerES5 жыл бұрын
Some key questions: 1- MCAS doesn´t appear in the MAX manuals neither in the 2 hours iPad training module. 2- So the pilots didn´t know the behaviour of the malfuctioning system they are fighting to fly the plane. 3- Boing relied in ONLY 1 AoA sensor as input to the MCAS system. (In my opinion that´s totally MENTAL). 4- FAA delegated the testing, validation and scrutiny of the MAX series modifications to Boeing. (That´s, to me, can only mean lack of integrity or plain corruption).
@reddog-ex4dx5 жыл бұрын
Thanks Juan, that was a very well done detailed report. A couple of years ago I watched on KZfaq a lot of aircraft crash investigations. After a while, I had to stop because, even though it was just the investigation, the fact that so many people lost their lives so suddenly and so violently really affected me. At a crash site, it isn't just airplane parts all over the place, it's body parts. One second their alive, the next... And now whenever there is a crash, I just want to cry for all those who lost their lives. I've heard NTSB investigators tell of how they had to over come that especially when the relatives come to the site. My heart goes out to them, the first responders and all involved in these investigations. I know the investigation has to be done so that it doesn't happen again. How many times has the NTSB come out with recommendations and the FAA dragged their feat (and more planes crashed because of the same problem) before implamenting the solution. It doesn't sound to me like Boeing put out a system that was tested enough before being released. The lame FAA, who are more concerned with the airlines and manufacturers making money than safety, is especially responsible for this loss of life. This reminds me of when the 737 had problems with the hydraulic valve that controlled the rudder all those years ago and took years before the problem could be replicated in the lab. I hope that a true and final fix is brought about before another 737 Max lifts of the ground.
@joso55545 жыл бұрын
reddog 458 More testing is not what lacked here. This is a (major) design fault. The systems should be safe enough to not cause a fatal danger from any single component failure (AOA sensor here), and this is achieved by proper fault-tolerant design choices (such as redundancy, cross-checking systems, sensor coherence monitoring, etc.)
@ashsmitty22445 жыл бұрын
Thank you for spending the time to share with everyone what you have learned. Greatly appreciated.
@kevinbrown16885 жыл бұрын
Thanks so much for an explanation that those of us that aren’t pilots can understand.
@annathrope18205 жыл бұрын
Thank you so much for this. I don't even bother with the news anymore. I go right to the experts. Great videos.
@cherylgarretson34415 жыл бұрын
Like you said...heart wrenching
@Miketar24245 жыл бұрын
Its good to hear the full story, and not just a sound bite. Thankyou for this report.
@blancolirio5 жыл бұрын
Thanks Mike!
@MikeCBA5 жыл бұрын
I can't believe what I've just heard. I've designed systems for far less safety critical applications and have placed far greater error checking into those systems than there appears to be in the MCAS. If it's true, to only have one sensor controlling such an powerful system is unbelievable, also to not have error checking that didn't have the ability to report when the sensor reading is fluctuating so wildly, is just plain negligent.
@RockinRobbins135 жыл бұрын
Trim overrun situations have been possible since the plane was originally put into service in its original configuration on April 9, 1967. The elevator trim cutout switches have been in the same place for 52 years and the memory procedure for trim system overrun has been in place for 52 years. MCAS is just one of the possible root causes for trim overrun. The remedy is to throw the elevator trim cutout switch to "cutout." What these pilots failed to do is fly their airplane after they threw the cutout switch, not properly managing altitude and airspeed. What they should have done is what every pilot learns in ground school before he steps into a Cessna 172 or other learner aircraft. FIRST FLY THE PLANE. Then when the plane is in a safe configuration of attitude, altitude and airspeed, ONLY THEN troubleshoot the problem. These guys, with a perfectly controllable airframe, neglected to fly it. Holding attitude with yoke only, they should have reduced throttle to level cruise level, waited for the plane to settle down, then with attitude and throttle entered a standard climb to a safe altitude and established straight and level cruise there. THEN AND ONLY THEN, one of them could have easily adjusted the manual trim and it would become a routine flight from then out. Depending on management, the tower or the captain, they could continue their flight or return to takeoff field. Don't forget, someone threw the elevator trim cutout switch back on, to use electrical trim on the yoke, then left it on so MCAS could crash the plane. There is a 5 second delay between when you input manual trim adjustments and MCAS begins commanding trim adjustments again. Had the captain turned the elevator trim cutout switch back to "cutout" immediately after his adjustment after violating procedure by turning MCAS back on, he would have been flying well over Vmo, but he still would have had a shot at saving the day. All he had to remember was that throttle....
@robroilen44415 жыл бұрын
@@RockinRobbins13 This guy gets it
@RockinRobbins135 жыл бұрын
@@robroilen4441 I'm not saying the system couldn't be made safer. I'm saying it's safe to fly as is.
@robroilen44415 жыл бұрын
@@RockinRobbins13 Agreed. I see a lot of people regurgitating the latest half-true mainstream media updates and calling for software fixes without addressing some really common sense flying practices that simply were not used in this accident. Sure, refine MCAS, but teach pilots to rely less on automation.
@RockinRobbins135 жыл бұрын
@@robroilen4441 _"Sure, refine MCAS, but teach pilots to rely less on automation."_ There's a reason lots of commercial pilots are also sailplane jockeys. Pure stick and rudder experience is golden, and it would have saved this Ethiopian Airlines plane. Yes, connect both angle of attack sensors to MCAS and the attitude readout from the normal avionics too. Let MCAS compare numbers and make rational decisions, alerting the crew when it sees a discrepancy. Tone down MCAS' power so that at full strength, pilots can still overpower the MCAS trim with the yoke. Of course that is speed dependent. At 500 knots, it would take very little trim before human muscles on a yoke would be overpowered. Have to make this work for normal flying speeds and aerodynamic control surface loads. If the pilot exerts more than a certain number of pounds force on the yoke in the up direction, let MCAS cancel and give the pilot control of the plane. With competent piloting, this could save lives. But we can't lose sight of the fact that no plane will ever be so safe that a sufficiently imaginative or determined pilot can't crash it. We have to get rid of the attitude that if a plane crashes we need to cripple the Airline manufacturer. It isn't automatically their fault. It isn't Boeing's fault here. They did everything, disclosed everything they knew to Ethiopian Airlines, gave complete instructions, warning that a faulty attitude sensor could cause a trim overrun, detailed the steps to compensate and instructed the airline to insert the bulletin in the Flight Operations manual. And it instructed the head of 737 operations for the airline to make sure all pilots were briefed on the seriousness of the situation. This garbage about Boeing not caring about airline safety, that they purposely rushed an unsafe airplane to market is slanderous. It's wrong. It's evil. Only live, breathing people buy airliiners. When is the last time a dead victim of a crash bought an airplane? The Preliminary Accident Report makes it very clear that Boeing cares about the safety of pilots and passengers who fly their airliners. They issued the bulletin before the FAA had any input at all in their zeal to notify customers of a situation that improperly handled could kill. When news media around the world stuff events into their agendas of anti-Americanism, anti-capitalism, anti-corporations, anti-government, whatever their enthusiasm, they do a grave disservice and sully the memories of those who died in this tragic accident. Nobody wanted this to happen. Let's bury the hatchet, ask the tough questions and make flying safer. But remember: no airplane is so safe that a sufficiently imaginative or determined pilot can't crash it. The only completely safe option is to ground everything that flies. And that would kill thousands, maybe millions of people.
@richc47us5 жыл бұрын
Thanks Juan....Great job...you make it easy to understand....
@Mikey3005 жыл бұрын
I only drive a (Mighty) M20C with a 2575 pound MTOW, but the electrical engineer in me wonders why the reported excessive rate of change in the pilot’s AOA sensor (dAlpha/dTime) didn’t cause the Flight Control Computer to disqualify that sensor’s input to the MCAS. Even if the MCAS system was operating on a single Alpha sensor, killing the MCAS system would be preferable to operating on a bad Alpha sensor. Did BEA mention the performance of the Alpha sensor during the time the MCAS was cut out?
@JoeLinux20005 жыл бұрын
My understanding is the MCAS only responds to a single sensor, and it might have been the one that was bad. That's one of the things that's wrong with the system. But deciding which one of two is wrong could be very problematic. It seems to me three or more sensors are in order. I have three themometers outside the window on my back porch. One is electronic, one is a bi-metal coil, and one is alcohol in a glass tube. Rarely do they fully agree.
@leem60115 жыл бұрын
In a refinery in critical systems, we have 2oo3 or 2oo2 - 2 out of 3 or 2 out of 2 before a critical safety device is activated. Seems they would have a similar voting in criteria on aircraft safety systems such as MCAS.
@Mikey3005 жыл бұрын
Internet Privacy Advocate which is related to my point: an excessive rate of change for Alpha, even on a single AOA sensor, ought to disqualify that sensor input to the flight control computer. Certainly it would have been preferable to have Alpha data from either AOA sensor available to the computer and to have the computer sound off (loudly) in the event of excessive rate of change or difference in absolute Alpha value. I wonder who among the Boeing engineering staff is going to turn out be the Roger Boisjoly of these accidents.
@WilliamJones-Halibut-vq1fs5 жыл бұрын
The architecture probably provides ‘fail safe’ stick-shaker operation at the expense of an erroneous high AoA input, which I assume is part of the high reliability requirement. Failsafe for stick shaker is opposite for MCAS.
@WilliamJones-Halibut-vq1fs5 жыл бұрын
Lee M I don’t think the old legacy systems architecture supports fault tolerance very well. It’s only duplicated not triplicated but pilots must decide what is working and what is faulty. Also if you get wire break on alpha sensor you want erroneous high reading for failsafe stick shaker and erroneous low for MCAS activation. Whoever had to program this pile of dog shit would’ve had their work cut out for them because the systems architecture wouldn’t support the kind of automation and failsafe fault tolerance required. I doubt 2oo3 is supported as configuration of I/O but would require explicit programming.
@humanonearth15 жыл бұрын
Very good analysis. Your final statement really gets to the heart of the matter: "...a situation which is virtually unrecoverable at high rates of speed close to the ground."
@candulagirl78175 жыл бұрын
Thank you Mr. Browne. I so enjoyed your narrative and in depth explanation. Found it so very interesting. Came across very knowledgeable & professional on the subject. Looking forward to your update. Feel sorry for the passengers and the crew that were desperately attempting to overcome a horrific situation.