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Air Travel Safety and the 737 Max 8?

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Twisties

Educate me.

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Joe Frickin' Friday
19 minutes ago, Twisties said:

Educate me.

waddyawannaknow?

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Twisties

Grounding justified, or no?  Summary of evidence, summary of response to Lion Air, summary of criteria for grounding decision, perspective on overall air safety trends (are planes too complex to fly, or are automated systems improving safety), whatever else may be important....  we have a bunch of experienced pilots here... just thought maybe we could have some relatively informed debate...

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Joe Frickin' Friday

I'm not a pilot of any sort, but I'll throw in my two cents.

 

Most commercial passenger jets will warn the pilot of an impending stall with a yoke-shaking  mechanism, designed to mimic the buffeting behavior typically seen on smaller straight-wing aircraft.  If the situation continues, the plane will actually push the yoke forward, forcing the nose of the plane to pitch down in a controlled manner.  The important thing to note is that the yoke-pusher is weak enough that the pilot can physically overpower it if he consciously chooses to.  So if the yoke-pusher is acting based on an erroneous stall warning, there's no special action that needs to be taken: the pilot just pulls back hard on the yoke and defeats the yoke-pusher.

 

On the 737 MAX 8, instead of pushing the yoke forward, the system adjusts the pitch angle of the entire rear stabilizer.  If the pilot believes the impending stall isn't real,  he can pull back on the yoke, and it'll move the elevator tabs, but those elevator tabs are meaningless against the control authority of that entire stabilizer.  And that's pretty much how the Lion Air situation started: a faulty airspeed sensor convinced the computer that a stall was imminent when in fact everything was fine, and so the computer insisted on pitching the nose down repeatedly.  On the 737 MAX 8, there's a button the pilot has to press to override this system, and it sounds like the Lion Air pilots either weren't told about this unique feature, or didn't remember it.  So they fought and fought with this thing until the computer finally won and flew the plane pretty much straight down into the ocean.  The way to prevent this particular type of crash from happening again is to ensure that the pilots are fully trained on the peculiarities of the MAX 8, including this unique stall management system and how to get around it if necessary.

 

While the Ethiopian Airlines flight was also flying erratically and eventually came pretty much straight down into the ground, eyewitnesses are claiming that the plane was emitting smoke, debris, and odd noises well before it crashed, which suggests a problem other than the pitch control issue that the Lion Air flight had. 

 

So even though there have been two crashes of the same aircraft type in less than a year, and both aircraft were very new, I think that's where the similarities end.  Absent any other information (e.g. something particular they've discovered about the MAX 8 that hasn't been made public yet), I'd say that grounding all MAX 8 aircraft is unwarranted, and that the decision(s) to do so are about bowing to public pressure rather than technical data.  

 

As it happens, there was a statement from the FAA this afternoon about "new evidence" from the Ethiopian Airlines crash site that helps justify the grounding, but they haven't yet said what it is.  Waiting to see...

 

 

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Paul De
54 minutes ago, Joe Frickin' Friday said:

I'd say that grounding all MAX 8 aircraft is unwarranted, and that the decision(s) to do so are about bowing to public pressure rather than technical data.  

 

I understand Ethiopia Air grounding its fleet, but I was suspicious about the EU grounding 737 MAX. I gave that announcement a bit of a side eye given the level of financial support that the Eurozone gives to Airbus. The US grounding seems like a giving into public pressure and the perception that the FAA is overly influenced by Boeing and the airlines.

 

Boeing didn't help itself as I understand it.  When the MAX series was released the new engines tended to make the plane want to nose up more than the previous generation of the 737 and at some point they programed in some additional nose down bias  to compensate and uploaded the software to the global fleet but didn't either communicate it well or maybe did it with no notification at all.  I believe this information came out in the Lion Air investigation, and while it could in reality be entirely unrelated the coincidental timing w/o full disclosure of the change fed the narrative that Boeing was covering up a major flaw in the MAX series.

 

Jumping to conclusion is a natural thing for humans and in an information vacuum speculation as conclusion can spin out of control. I am sure a lot of Boeing engineers are now going with little sleep and a bottle of Tums on their desks frustrated that the data they need isn't in hand yet to make an informative decision on the action to take.

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Skywagon

It will take some time to sort out what new info the FAA has. If it were my decision, would I ground the US Fleet?  Yes....without any hesitation.  Why?  The recent crashed are too similar.  It could be mechanical, training, or a combination of both.  As the investigation/research continues if there is a common cause, it will be found just like the hard over rudder of 737's a few years ago.  Do we wait for one more and say ok that's enough, or do we take caution now?

 

Yes it will create some hardship for traveler, airlines, and some economic issues....but if your call and one more went down causing the loss of life, how would you feel about that decision to wait and see.

 

Boeing issued and emergency software patch this week to address the Lion crash.  Did they find a fault or just adding more safety.  They didn't really publicly say what that patch was for.  

 

For me as a pilot I would hope you would be happy I leaned forward on safety and a little less concerned over stats and financials.  I was never asked to pilot a plane with ops saying I think it is ok :)

 

 

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John Ranalletta

See blancoliro for commercial pilot's take.

 

 

 

 

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Joe Frickin' Friday
7 hours ago, John Ranalletta said:

 

Porpoising, AKA phugoid flight, is associated with a complete lack of pitch control input, from either the pilot or the autopilot.  The Lion Air flight was quite the opposite: the computer pushed the nose over until it was satisfied the stall condition was eliminated, and then it let the pilots pull the nose back up, then the cycle of control inputs began again.  Given the similar aspects of the flight path for both planes, it's possible the same thing was happening, but eyewitnesses reported smoke and noise from the plane before impact, suggesting some other sort of failure.  Maybe they were misinformed about what they saw/heard, or maybe there was a failure that was caused by the wild flight.  Will be interested to see what comes out of all this.  

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Skywagon

porpoising will almost always be pilot induced as the servos can not act fast enough to create porpoising. It may be purely by the pilot with no input from the plane itself or it most likely caused by the trim on the elevator running one way and the pilot pushing or pulling the other. Trim on elevators move slowly.  If they didn't it would nearly impossible to level the plane.  Manual input can happen as slow or rapidly as you want.  What caused this oscillation?  Don't know but time will tell.  It could be the new program commanding one way and pilot manually overriding, TCAS working, or a number of things....time will tell.  

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Skywagon

It's hard to say what that will mean.  Remember there are really 3 parts of climb and descend ( 4 if you count thrust).  The stabilizer, the elevator, and trim.  If I remember correctly the autopilot can be overpowered with roughly 25 lbs of force.  Not a real big deal, but this new MCAS as I'm told, senses stall and rolls the stabilizer to the stops full down.  With the stabilizer pointed that far down, if that is what happened, even if the pilots were to pull back full on the yoke it is unlikely they have enough surface in elevator and trim to overcome the effects of nose down on the stabilizer.  I don't know any more than the next person what happened yet, but smells like MCAS in some way.  Maybe they were trained on it, maybe not...even if trained did it lock the stabilizer against the stops which  would not have given the pilots the ability to create climb by simply pulling back?  As a last result did the pilots go to take off power to create climb?  Don't know...but possible.  Killing the autopilot is something pilots do multiple times in any flight by just pressing the disengage switch on the yoke...so autopilot unlikely the issue... I'll do some research but I think the stabilizer is hydraulic.

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Joe Frickin' Friday
11 hours ago, Skywagon said:

If I remember correctly the autopilot can be overpowered with roughly 25 lbs of force.  

 

Unrelated to the current 737 MAX crashes, but Aeroflot 593 was an interesting crash that involved such a manual override of the autopilot:

Quote

With the autopilot active, Kudrinsky, against regulations, let the children sit at the controls. First, his daughter Yana took the pilot's left front seat. Kudrinsky adjusted the autopilot's heading to give her the impression that she was turning the plane, though she actually had no control of the aircraft. Shortly thereafter, Kudrinsky's son Eldar occupied the pilot's seat.[2] Unlike his sister, Eldar applied enough force to the control column to contradict the autopilot for 30 seconds. This caused the flight computer to switch the plane's ailerons to manual control while maintaining control over the other flight systems. A silent indicator light came on to alert the pilots to this partial disengagement. The pilots, who had previously flown Russian-designed planes which had audible warning signals, apparently failed to notice it.

 

Animation with CVR audio is here.

 

 

 

 

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Skywagon

if you are interested here is a link to some info on mcas   

https://www.avweb.com/

 

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Twisties

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Joe Frickin' Friday

The news this morning reported that the day before the Lion Air plane crashed, it experienced the same MCAS activation problem, but an off-duty pilot happened to be in the cockpit and showed the crew how to override that system with the previously mentioned button.   It was of course a different crew on the day of the actual crash, and so they were not aware of that MCAS override button - but one would have thought the incident on the day prior to the actual crash would have been reported so that the plane could be taken out of service and repaired.  

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Paul De

The how of these two flights crashing are now well into the investigation process, and the why of these crashes are now beginning to be brought to light. Early on the MCAS system and training jumped out as a first why.  The next why coming to light appears to be that the FAA may have not had the expertise and resources to adequately certify the 737 MAX ceding much of the certification process and systems review to Boeing engineers.  While I support a collaborative process between the private and public sectors to keep any certification process from turning into a bureaucratic mess it seems that Boeing may have had too much sway in the go gate decisions.  While I believe that no one at Boeing was intentionally covering up a fatal flaw in this aircraft's design and systems it is also can't be ignored that the FAA ceding this amount of authority to certify to Boeing exposed the process to make a No-Go decision with those with a greater conflict of interest to say No-Go.  This is a dilemma  for the US now as It seems the pendulum of government over-site and regulation has maybe swung too far to hands off and safety is beginning to suffer...and not just in aeronautics, we see signs of this in our food and water resources as well.

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John Ranalletta

Similar (IMO) to events leading to Challenger gasket failure.  There's lots of direct and indirect political and financial pressures to get these programs off the ground, so to say.

 

Boeing and other mfgs and operators exist in a zero defect world.  Too much caution is not enough until stockholders start grousing.

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Bud

My wife, daughter and grand daughter are due to fly back from SF in a couple of weeks on a Max 8. I'm personally happy to see them grounded until there is more info. When lives are at stake, error on the side of caution is the right thing to do.

 

Stockholders will start grousing when the price per share starts dropping as a result of these accidents. Someone one, somewhere made a decision that will not be cheap or easy to overcome. I doubt it was a "rogue, low level engineer" no more so than in the VW emissions fixing scandal.

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John Ranalletta

Southwest pilots had flown 41,000 flights with the Max w/o incident, so, that's reassuring.  

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Stir
On 3/20/2019 at 12:22 PM, Bud said:

My wife, daughter and grand daughter are due to fly back from SF in a couple of weeks on a Max 8. I'm personally happy to see them grounded until there is more info. When lives are at stake, error on the side of caution is the right thing to do.

 

Stockholders will start grousing when the price per share starts dropping as a result of these accidents. Someone one, somewhere made a decision that will not be cheap or easy to overcome. I doubt it was a "rogue, low level engineer" no more so than in the VW emissions fixing scandal.

 

My wife and I just flew back from Austin on a 737, 700.  Had it been the Max however, I would have been fine with that.  There isn't a MAX pilot at Southwest that doesn't know how to push a button.

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Bud

I have faith in SW as we fly them all the time.

 

A member of our church is a pilot for SW and said he had 0 qualms about flying them.

 

As of now, the FAA has decided that no matter how good the pilot may be, they won't fly.  I'm OK with that.

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mbelectric

Surprise, Surprise. New news out suggests cost cutting measures by Boeing to purchasers may have been an issue here.

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MikeRC

The preliminary report from the Ethiopian Air crash is pretty depressing (one might even say damning).  Loss of one sensor shortly after takeoff lead to activation of the MCAS system.  The pilots recognized the problem and disabled (or at least attempted to disable) the MCAS system but it was too late to correct the planes attitude/trajectory.   All the while dealing with distracting (and some erroneous) warnings/data feedback in the cockpit.   

 

Preliminary report on doomed Ethiopian Airlines crash

 

The best hardware & software can run into situations no-one expected or anticipated resulting in fatal results.  I think the 737 MAX is going to be grounded for quite a few more months. 

 

More importantly for Boeing and the airlines choosing to purchase the plane is how long will it take to restore public confidence in the product. 

 

Michael Cassidy 

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Bill_Walker
7 hours ago, MikeRC said:

Loss of one sensor shortly after takeoff lead to activation of the MCAS system.  The pilots recognized the problem and disabled (or at least attempted to disable) the MCAS system but it was too late to correct the planes attitude/trajectory.   All the while dealing with distracting (and some erroneous) warnings/data feedback in the cockpit.

 

When Boeing had their big "rollout" of the original software fix last week, they had a bunch of pilots go through simulator training without the fix and with it.  Without it, simulating MCAS failure, pilots had about 40 seconds in which to diagnose the problem and take action before it was too late to save the plane!

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RPG

I'll keep my reply simple and I am not a pilot. Although my brother flew for American Eagle and my grandfather flew in WWI.

 

If the problem in both crashes was related to the auto pilot taking control, why wouldn't the pilots disengage it to fly the plane themselves?

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Joe Frickin' Friday
56 minutes ago, RPG said:

I'll keep my reply simple and I am not a pilot. Although my brother flew for American Eagle and my grandfather flew in WWI.

 

If the problem in both crashes was related to the auto pilot taking control, why wouldn't the pilots disengage it to fly the plane themselves?

 

If you're thinking about the classic autopilot that maintains an assigned heading/speed/altitude, that system wasn't the problem.  The problem was a separate system for managing handling characteristics that was also used for averting stall conditions.  

 

The 737 MAX 8 is different from the old 737 design in that it has larger engine nacelles, and they are mounted further forward and higher up.  The result is that in certain flight conditions, when the slipstream hits the underside of those nacelles, it makes the plane want to pitch upwards.  To mitigate this, the MCAS (Maneuvering Characteristics Augmentation System) uses jackscrews to adjust the angle of the entire horizontal stabilizer as needed to restore better flying behavior.  

 

That same system kicks in whenever the plane thinks it's about to enter a stall condition, as measured by angle-of-attack sensors near the nose of the plane.  Other planes generally use a stick pusher to force the pilot's control yoke forward; it's fairly compelling, but still weak enough for a pilot to overcome it with brute strength if he thinks he knows better.  But on the MAX 8, when the MCAS kicks in, your strength doesn't matter: the elevator tab, even at its most extreme position, just can't provide enough aerodynamic force to overcome what MCAS does with that entire horizontal stabilizer.   If you want to get around that system and bring the nose back up, there's a unique procedure to follow to disable it.  The pilots on the Lion Air flight didn't know about that procedure; they were still trying to figure out what the hell was going on when the plane flew more or less straight down into the ocean.

 

Supposedly the Ethiopian pilots did know about MCAS, and disabled it shortly after problems began.  What happened after that still seems a bit murky, but it sounds like a back-and-forth fight between the pilots and MCAS, turning it on/off and maybe trying to change the angle of the stabilizer manually with a manually-operated trim wheel.  It's been only about six weeks or so; I'm very interested to read a final report about the exact sequence of events on that plane, but I guess we'll have to wait.

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RightSpin

There are a lot of misconceptions being reported by the media regarding this incident.  I've been following this since the Ethiopian plane crash and have learned a lot from other pilots and my reading of the preliminary report.  Here's  what I've learned:

 

1.  MCAS is a system designed to make the 737 MAX feel the same as previous models.  This helps airlines reduce the amount of training and certification require to operate a mixed fleet of 737's.  This is a specific request airlines made of Boeing when the 737MAX series was being developed.

 

2.   The plane can fly just fine without MCAS being enabled.  In fact, the Runaway Stab proceedure specifically requires that MCAS is turned off if there is a problem trimming the airplane.  It's only there to make the MAX feel like it's predecessors.  This fact has been seriously misreported by the media.

 

3.  Contrary to media reports and a misreading of the preliminary report by the spokesperson for Ethiopian Airlines, the pilots did not follow all procedures correctly.  Roughly half way into the six minute flight airspeed reached Vmax (maximum allowed airspeed for the aircraft) and remained above that for the duration of the flight.  The over-speed warning buzzer sounded the entire time airspeed was exceeding Vmax, yet the crew failed to reduce throttle positions which is required in such a situation.  There were eyewitness reports of the plane smoking and "rattling like it was coming apart" just before the impact.  This is because the throttles were still at takeoff settings, and airspeed at that point had advanced to more than 200 knots above Vmax causing the airplane to begin shreding itself due to the excessive speed.  I repeat, the throttles were never moved from their takeoff settings the entire flight.  Which brings us to the next point.

 

4.  The 737 (all models) is very difficult to trim manually once it's out of trim and above normal speed.  The reason for this is how the trim system works.  In the 737, trim is achieved by moving the stabilizer, not trim tabs like some aircraft.  If trim becomes significantly out of adjustment, the air pressure pressing on the stabilizer acts as a friction agent working against moving the jack screw manually.  The higher the airspeed, the harder it will be to adjust.  One pilot mentioned that he was taught that in addition to reducing airspeed to reduce the amount of down force on the jack screw, the nose may also be need to be dropped a little to get it back to a manageable level.  Perhaps the pilots were unaware of this

 

5.  For reasons which are still unknown, one of the pilots re-enabled MCAS just prior to the final plunge to the ground.  This was probably an act of desperation, but certainly against runaway-stab procedures which clearly state that should MCAS need to be disabled it is to remain disabled for the duration of the flight.

 

6.  Finally, even though the pilot had a reasonable amount of flight experience (8000+ hours) the first officer did not (only about 200 hours).  This put a lot of stress on the pilot in a situation which was already highly stressful.  That lack of experience in the right seat has to be considered.

 

There will be a final report eventually.  It will likely have all the answers to this tragedy, and provide a guide for changes going forward to make an already safe system even safer.  While it's human nature to want to know the answers right away, we must be patient and let the right people do their jobs.  Speculation isn't helpful, and repeating misinformation is harmful.

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Paul De

More not so good news for Boeing.  Seems there was a warning light when sensors to provide input the system in question were in conflict.  All 737 Max planes had this light which was meant to be a std feature active for all versions of that system but Boeing later realized the warning light only worked if the the airline had paid for an optional upgrade on that plane.  Only 20% of the delivered planes had an this warning light functional and this issue was known by Boeing well before the Lion Air crash but they said nothing to the FAA or any airlines flying these planes as they decided it was not a critical safety issue.  In retrospect this warning light would have provided some critical information in the Lion Air crash.

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John Ranalletta

 

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Paul De

As a former technology manager I find the video interesting stuff but I have also learned over the years that facts don't manage the narrative. Unfortunately all the wonky technical facts and explanation of the systems and the operational procedures involved misses the bigger public relations damage Boeing is experiencing which was brought on through their decisions to not be proactive with communicating to the purchasers of the MAX plane about why they included the MCAS system on this version. Likely worse for Boeing is the discovery and lack of a proactive plan to correct a nonfunctional standard warning light on 80% of the planes delivered.  Sadly,  Boeing will find the cost of managing the loss of reputation is going to out strip any savings they expected by keeping quiet about the MCAS system and the nonfunctional warning light.   Unlike wine, bad news never gets better over time.

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John

I just stumbled on this topic. I fly the 737-800 and -700, and my company HAD an order for Max-8, which it has since changed to the Max-10.

 

A couple of things about MCAS - It only takes its data from one alpha vane at a time. Therein lies the problem: No redundancy and no comparator (well, not enabled, as Paul wrote above) to validate a good side . Had it been installed/enabled, the crew would have got an "AOA DISAGREE" message on one of their screens. That would have made resolution of part of the problem easier. It appears the Ethiopian was flying on a faulty captain's side alpha vane, where the FO's side was giving valid data (but not in use, by design). Case for the AOA comparator and dual sensing to be standard...

The description of how it works has been covered earlier. Just a couple of things - it doesn't run through the autopilot. It runs through the Stab Trim system. In fact, if the autopilot is on, MCAS is disabled. If the autopilot is off, MCAS inhibits autopilot (if it is commanding nose-down on the Stab Trim).

 

Now for the Stab Trim system: As someone mentioned, it moves the horizontal stabiliser (for a whole bunch of reasons). In the 737, movement for any reason is visualised (and audible) by the spinning wheels either side of the pedestal. The most common reason for the trim to move is the pilot making a manual trim input via the control yoke switches to trim out stick forces, just like any other aeroplane (including most jet transports). Another reason it moves is in response to a speed trim input. (Description below).

 

Speed trim is applied to the stabilizer automatically at low speed, low weight, aft C of G and high thrust. Sometimes you may notice that the speed trim is trimming in the opposite direction to you, this is because the speed trim is trying to trim the stabilizer in the direction calculated to provide the pilot with positive speed stability characteristics. The speed trim system adjusts stick force so the pilot must provide significant amount of pull force to reduce airspeed or a significant amount of push force to increase airspeed. Whereas, pilots are typically trying to trim the stick force to zero. Occasionally these may be in opposition.

 

So, from a pilot's perspective, it's normal for the Stab Trim wheels to run on their own just after takeoff in response to a speed trim input. To me, I'm expecting it to do so. Perhaps the crew mistook the MCAS inputs for Speed Trim inputs and didn't (initially) think anything was out of the ordinary until the trim continued to run.

 

To me, an increasing nose-down trim with higher than normal rear control column force would (in the absence of any knowledge of the presence of MCAS), would make me assume a runaway stabiliser, and run the memory items for the Runaway Stabilizer Checklist. That would stop the control column force from getting any worse, and give the crew an opportunity to save the day with the manual trim. The Ethiopian crew actually started to do this, and the MCAS sent several nose-down commands to the now disabled Stab Trim system. For some reason they reinstated the Stab Trim Cutout switches, and the MCAS took over again. The rest is history...

 

The fact that the thrust was still at takeoff or climb setting tells me that for some reason they did not control the thrust (basic stuff). When you're well over VMO, you're now in test-pilot territory. The excessively high speed probably contributed to their difficulty controlling pitch and/or using the manual Stab Trim.

 

Boeing is going to take one for this. Who in their right mind would only use a single, non-redundant system for part of the flight controls, and then give absolute minimum info to those who operate it?

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Skywagon

Hey John thanks for detail. AT VMO are there audible speed warnings  I’ve never been a fan of AOA. Seems both crews may have entered overload with many things happening at once. If MCAS was engaged would it have been audibly announced-lights or silent. If recognized how difficult would it have been to override MCAS. with the negative G’s it would seem MCAS should disengage   

 

Good to have a knowledgeable person help us with all our speculation. Thanks for education

 

 

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John

Hi Skywagon,

yes, there’s a clacker that goes off at VMO/MMO. I understand the captain’s stick shaker was going off as well due to his alpha vane indicating 74deg AOA.

That would be confusing in the extreme.

There’s nothing to get the crew’s attention, such a horn or light. The first thing you know is when the stab trim starts running, and as I mentioned in my previous post, could be mistaken for the speed trim (normal). The difference is the speed trim runs for up to a couple of seconds, whereas the MCAS will run for up to 10, then pause, then run again for up to 10 seconds (if the condition still exists), then pause again. The process repeats until until the condition no longer exists, or the crew place the stab trim cutout switches to ‘cutout’.

There are 3 ways of stopping the MCAS. 2 of these are temporary. These are operating the control yoke trim switches to trim the nose (after a pause, the MCAS will run again as described above). The second is to extend flaps 1 or greater (<= 250kts). Flaps up is a pre-condition for MCAS to function.

The third is the stab trim cutout switches, which stops the stab trim running whilst ever these switches are left in ‘cutoff’.

I don’t know if G has any effect on MCAS. I doubt it because it functions in relation to the thrust-pitch couple and AoA.

 

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John

I meant to mention that the MCAS will still send a ‘trim nose down’ signal to the stab trim system, even when the stab trim is disabled via the cutout switches. This happened several times on the Ethiopian flight. Unfortunately, the crew switched the stab trim back on, and the rest is history :(

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Skywagon

Thanks John...sure seems like a full disengage on the yoke should be part of the formula...I watched a buddy go full stall into the top of trees in a warthog on dual flameout...he walked away...well after they stopped shooting at him...rather after we stopped them from shooting at him.  Had MCAS been on board he probably would have face planted.  Im all for the technology, but at some point the highly skilled train pilots should be able to go seat of pants stick, ball.

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John
4 hours ago, Skywagon said:

Thanks John...sure seems like a full disengage on the yoke should be part of the formula...I watched a buddy go full stall into the top of trees in a warthog on dual flameout...he walked away...well after they stopped shooting at him...rather after we stopped them from shooting at him.  Had MCAS been on board he probably would have face planted.  Im all for the technology, but at some point the highly skilled train pilots should be able to go seat of pants stick, ball.

David,

Some sort of aural call would solve the problem. We get callouts for all sorts of critical events or impending events.

 

I have a mate who flew the A-10 for you guys. He came over here with his Aussie wife about 25 years ago to fly. I remember we were doing a simulator session, and had a bit of time left at the end. The upshot of i† was that we ended up flying down Sydney Harbour at about 100' at VMO, and just before we got to the Sydney Harbour Bridge he did a hesitation roll and flew us inverted under the bridge at VMO. Out the other side he did the same and then did a split-arse turn around the city hi-rise :4323:

In this video he's flying an L-39 jet at Bankstown AU (where I learned to fly). He's in the front, and you can hear him talking. Callsign VIPER.

 

VIPER flies his L-39 at Bankstown, AU

 

He's now back home flying for Go-Jet based in St. Louis.

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Paul De

This may be a naive question, but if the new engine used on the Max caused the nose up tendency VS the previous engine, could this have been addressed by mounting the engines in a way that canceled that tendency, as in further forward to move CG forward, or slightly different angle to counter the greater thrust/torque?  I'm guessing the software solution was less costly than engineering the sameness to previous model into the plane itself, but at the expense of KISS for the pilot.

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Skywagon

The l39 is quite fun....got to ride this a few years ago out of Livermore, CA

 

Image result for rich perkins - l39 firecat

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Paul De

And the hits just keep coming. 

 

Article basically covers AA pilots and the pilots union angry and pushing Boeing to be more open and proactive on a fix with Boeing pushing back essentially wanting to keep the issue on the down low.  Boeing is following the path that will result in failing to get in front and control the narrative. If a Boeing exec doesn't fall on the sword soon and they stay with this keep it quiet strategy they may get permanently branded as a bad organization and that sadly may not be recoverable from.

 

https://www.nytimes.com/2019/05/14/business/boeing-737-max-ethiopian-plane-crash.html

 

Congress is hauling in the FFA to "review" the issues around the certification of the MAX version of the 737.  This will no doubt take the form of a bureaucratic CYA session and abdication of responsibility by throwing Boeing project managers under the bus.

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John Ranalletta

The fun never stops for Boeing:   

 

After a comprehensive inspection of 737NGs across the world, Boeing has said 36 737NGs have developed cracked wing supports, resulting in emergency groundings of the damaged planes with pending repairs, USA Today reported.

 

737ng.png

 
 

The 36 planes only represent 5% of the 686 planes inspected. From 1997, Boeing produced 7,043 of the aircraft (as of Aug. 29, 2019 figures), there is no report on how many of these planes are currently flying and or how many Boeing plans to inspect. 

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Joe Frickin' Friday
13 hours ago, John Ranalletta said:

The fun never stops for Boeing:   

 

For everyone, really.  According to WikipediaBoeing has delivered 393 of these planes, and they're sitting on an other 300.  That's almost 700 planes - $8.4 billion worth of hardware - that's been parked for the better part of a year and not making money for anyone, either Boeing or the airlines who purchase the grounded planes.   

 

Early in this thread I expressed doubts about the necessity of the grounding, but that was before all of the details of the second crash came out; the grounding is clearly required, but holy crap, what a mess for everyone.  The Wikipedia page says that several airlines intend to resume flying these planes in December or January.  However, it also says this:

 

Quote

As of October 2019 the disagreements over various system revision details as well as Level of Involvement (LoI) between the two leading aviation authorities, FAA and EASA, could delay the 737 MAX return to service.

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As of October 8th, FAA and EASA were still reviewing changes to the MAX software, raising questions about the return to service forecast.

 

Nuts.

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Paul De

The pendulum has indeed swung way back the other way and it was inevitable.  The FAA got dinged hard for yielding too much freedom by Boeing to self certify, so now they will have to have their nose into all the minutia to show that they are on top of it. 

 

I see the cracked wing support finding as an engineering or assembly issue and quite separate from the MCAS debacle.  While it is reasonable to assume that attaching wings securely should be well established technology in the real world weird stuff happens.  The upside is that the inspection regimes worked in this case and an update will be implemented without a loss of safety in that platform.  Unfortunately, following the MCAS debacle it only adds to the loss of Boeing's credibility and competency.

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John

The pickle fork issue only affects high time/high cycle airframes. Our entire fleet is going through the inspection schedule, and none have had any cracks.

 

Stuff like this pops up on all types from time to time. They are machines after all. I think someone’s just taking an opportunity to bash Boeing a little more.

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John Ranalletta

An article re: pickle fork issue with illustrations for the unwashed like me. 

 

image.thumb.png.35b14bf45bb064b0bae268459fbbc4a0.png

 

 

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