Curious Mind on the 737 grounding

Fly Dawg

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I realize this completely off topic. That is why I am posting this here. As one who looks at flight data quite often, I am curious to know where the "supposed" data comes from that resulted in the grounding of the 737 Max 8. Being that the flight recorders have yet to be analyzed from either of the 2 crashes, where does this "supposed data come from, that would lead to this? I have seen numerous reports of pitch angle deviations during flight, presumably shortly after takeoff. As far as I am aware there is no telemetry transmitted from each individual aircraft to a ground station. Radar data, and or satellite data are iffy at best in an analysis of this sort. Can someone explain where this data originates? Or is there any "firm" data that would support the grounding of the aircraft other than the actual flight recorders? This has me intrigued, as to the reasoning. Not to say it is a bad thing. Far from that, but I am very curious as to the "origin" of the data that led to the grounding.
 
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sar104

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I realize this completely off topic. That is why I am posting this here. As one who looks at flight data quite often, I am curious to know where the "supposed" data comes from that resulted in the grounding of the 737 Max 8. Being that the flight recorders have yet to be analyzed from either of the 2 crashes, where does this "supposed data come from, that would lead to this? I have seen numerous reports of pitch angle deviations during flight, presumably shortly after takeoff. As far as I am aware there is no telemetry transmitted from each individual aircraft to a ground station. Radar data, and or satellite data are iffy at best in an analysis of this sort. Can someone explain where this data originates? Or is there any "firm" data that would support the grounding of the aircraft other than the actual flight recorders? This has me intrigued, as to the reasoning. Not to say it is a bad thing. Far from that, but I am very curious as to the "origin" of the data that led to the grounding.
It's the ADS-B and satellite tracking altitude data, which show vertical speed oscillations with a periodicity of around 15 seconds that are very similar to the Lion Air crash and are, apparently, characteristic of MCAS intervention.
 

captainmilehigh

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I’d speculate that the grounding of these Boeing Max 8 aircraft is just a precaution until the source of the issue is located. I very rarely rely on the flight director/ auto-pilot, or autonomous flight systems on my climb-outs or approaches. I’d rather hand fly the aircraft. Not that I don’t trust these systems, it’s just a preference of mine I’ve had for many years.

But, if these systems are at fault........or it becomes both system failure AND pilot error, it’s best if these aircraft are out of service until that determination is made.

I too am watching for the outcome. Until then, there are thousands of other very airworthy aircraft to choose from.
 

captainmilehigh

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It's the ADS-B and satellite tracking altitude data, which show vertical speed oscillations with a periodicity of around 15 seconds that are very similar to the Lion Air crash and are, apparently, characteristic of MCAS intervention.
True. The MCAS may be the culprit here. But, it can be overridden with the trim wheel, although only for 5 seconds before the MCAS reactivates. To disable the MCAS system fully, the STAB TRIM switches need to be turned off.

If somehow these systems aren’t operating as designed, it would cause the aircraft to oscillate uncontrollably. Again, this is in manual flight mode.

Modern technology is fine, when it works correctly. It will be interesting to see the investigations outcome. I don’t fly the 737 Max 8, but many of my fellow pilots do.

It’s best these birds are parked until this is resolved.
 
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From what ive read it has to do with the "power steering" per se, more specifically the acsend assist at the stick. The software incorrectly "assists" in the wrong direction, in this case, it tries to descend, fighting the pilot pulling back on the stick to ascend, which appears to be the case in both the crashes in the last 6 months. But yes, no data to confirm this yet from the flight recorders, so it's still speculation. But scary enough to ground those AC.
 
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Fly Dawg

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It’s best these birds are parked until this is resolved.
Agreed, however it is the initial analysis the concerns me somewhat. The data at this point is still circumstantial. And the data utilized to determine the grounding, at least as far as I can tell is also the same. As I said before, no issue with the grounding, but for myself it is more of a curiosity for the reasoning/determination.
 
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captainmilehigh

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Agreed, however it is the initial analysis the concerns me somewhat. The data at this point is still circumstantial. And the data utilized to determine the grounding, at least as far as I can tell is also the same. As I said before, no issue with the grounding, but for myself it is more of a curiosity for the reasoning/determination.
Yep, pretty much fear-fueled caution at this point. Many countries that utilize this aircraft lack the technology to investigate these failures. I think I read that the NTSB is offering their services. Good idea, since these aircraft operate worldwide, and many, including foreign owned and maintained aircraft, frequent US Airspace.

Pilot training on these Boeing 737 Max 8 300 and 400 series is extensive here in the US. But many foreign aircrew have far less flight hours and overall training on these aircraft. Unless aircrews are fully trained in these MCAS and FBW (fly by wire) systems, it becomes much more complicated than stick and rudder.

I too am waiting to see/hear results of these failures.
 

Fly Dawg

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I too am waiting to see/hear results of these failures.
Ditto.....For now we wait. Was just curious as to how others related to the existing data, such that it is would attempt to make a conclusion based on the "as is" situation. Interesting conversation regardless of the outcome. Although I must say that prayers go out to the passengers and family of both flights.
 
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For those interested in the recent spate of accidents involving Boeing's
> newest 737 variant, the real story of what is going on behind the
> scenes is
> largely not being reported.
>
> It was interesting to note that President Trump alluded to the problem
> in a
> round about way, but unless you are a pilot you probably missed the point.
> In essence, President Trump was saying that technology is a poor
> substitute
> for a qualified pilot in command.
>
> One of the most basic skills a pilot learns from day one is energy
> management of the airplane. If the plane is too slow, it will literally
> drop from the sky. Too fast and the wings/airframe can come apart with
> disastrous consequences.
>
> In the history of commercial aviation in the US and western countries, the
> first crop of pilots to enter commercial service were the post world war
> two pilots. Those guys were the real deal and not only hand flew
> almost all
> of their hours but also in some of the most demanding conditions. The
> second wave were the airport kids who just fell in love with the idea of
> being a pilot and scrimped and saved to take lessons. Both categories of
> pilots were skilled in the art of aviation.
>
> With the explosion of second and third world travel, there were not even
> close to the amount of skilled pilots to fly the thousands of new
> generation planes coming out of airbus and boeing. Unline Cathay
> Pacific, a
> Hong Kong airline that was almost exclusively piloted by british pilots,
> the new asian airlines wanted asian pilots to man the cockpits...often
> with
> disasterous results. Asiana flight 214 crashed in SFO in 2014 because the
> pilots did not know how to hand fly the plane when the ground based
> approach ILS was out of service.
>
> Boeing, the FAA and worldwide aviation agencies track not only accidents,
> but also INCIDENTS…crap that was going sideways but didnt result in a
> crash. The number of unqualified pilots from asia and africa was plain to
> see in the number of errors being committed on a daily basis.
>
> To make a long story short, airbus saw this eventuality decades ago and
> implemented automatic safety systems in anticipation of unqualified
> aircrews. Boeing resisted for a lot of very good reasons...but after the
> Asiana crash, the chinese government basically told Boeing to
> "idiot-proof"
> the 737 as china would end up being the biggest purchaser of that model.
> Since Boeing had opted not to add automated control systems (which often
> override pilots inputs) they were forced to apply a band-aid solution
> which, unfortunately was not done well. Only one sensor was driving some
> very complicated algos which worked against the pilots decision making
> inputs.
>
> The fact that the asian and african pilots were essentially unqualified is
> highly embarrassing to the respective governments and boeing kept it
> quiet.
> When ALPA, the pilots union reps found the system was added without
> informing the pilots, they went insane...
>
> However, what they DON'T know, is that the MCAS system can be enabled or
> disabled per plane, and can be done remotely on a real time basis via
> uplink. The US airlines management, due to the superior training and
> piloting skills opted NOT to activate MCAR...but the asian/african
> carriers
> DID. That is why most of the “ crappy" airlines self grounded while
> all the
> major US airlines are still flying without a problem.
>
> Its a very PC issue, but basically comes down to 30-40% of the global
> pilot
> population are really not qualified to be pilots, but more just data input
> managers.
>
> Additional comments. Friends who will remain annomous (by initials only),
> long ago confirmend the above. One (IM) who worked under a Boeing contract
> giving simulator training South Koreans, just shook his head when he
> related tales of cockpit coordination. It was a South Korean flight 007, a
> Boeing 747, killing 269 persons, that the Russians shot down because of a
> one digit error entered into the INS system. For a lenghtly, but
> questionable analysis see:
>
> Study Says Korean Airliner Was on Its Intended Course When Downed in '83
>
>
> Another (BH) who retired from Delta a dozen years ago once told me he
> would
> never allow his family to fly on a foreign air carrier. There are a few
> exceptions to that, I'm sure. We are flying COPA in a coyple weeks, they
> have had only one fatal accident back in the 1990's, the result of an
> instrument failure.
>
> The old addage still applies: *To make things on the ground appear
> smaller,
> pull back. To make things on the ground appear larger, keep pulling
> back!!*
>
And as a pilot I will add my two cents worth "maintain thy altitude and airspeed lest the ground fly up and smyth thee".
I also want to add the Herman who sent this to me was also a crop duster as I was, you really learn to fly when you are two feet off the ground and dodging trees and power lines.

Nick



 
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