Boeing - Design Issues...

Discussion in 'Rules and Regulations / Flight Safety / Better Pil' started by TXFlyGuy, Apr 11, 2019.

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  1. Oct 19, 2019 #281

    flyboy2160

    flyboy2160

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    ...except you saved the really juicy stuff somehow (Find A Way!) just in case you got caught in the wringer.....
     
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  2. Oct 19, 2019 #282

    davidb

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    This discussion is like the one about the Air France stall crash. People blaming AirBus for a faulty pitot heat system while pilots are pointing out that we are trained to deal with indication anomalies. Unfortunately, the person at the controls wasn’t trained.

    With this Max discussion, it’s quite a bit more involved but evidence indicates the guys in the right seat weren’t trained to hand fly a 737 and the second guy in the left seat continued to try to engage the autopilot. Flawed design and MCAS aside, that is a training issue. With any of the indications he had, autopilot engagement is prohibited per the flight manual (POH).

    Spank Boeing and fix the Max but we can still ponder what we expect from the guys at the controls. A design flaw on some other airliner that will cause unforeseen problems will happen in the future. The final outcome will depend in part on how the pilots handle the situation. We are quick to laud hero pilots yet they are the first to admit that they are just a product of their training and experience.
     
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  3. Oct 19, 2019 #283

    Wanttaja

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    99% of my work-related emails were on classified systems, not the normal Boeing system, and I rarely deleted anything. Several of the systems were Government-owned, so the Fed would already have the information.

    My last job at Boeing, I had the usual unclassified Boeing address (find me in the zzzz section in the Boeing address book, now), and four different accounts on different classified systems, which were restricted to certain topics. Vishnu help you if you needed data transferred between them; multiple layers of security involved.

    Ron Wanttaja
     
  4. Oct 19, 2019 #284

    Wanttaja

    Wanttaja

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    This is probably not a subject I should be chiming in on, basically because I'm just a dumb ol' Fly Baby driver/retired Space Engineer with no experience with flight control systems that don't involve 1/8" cable and weldwood glue or hydrazine and control moment gyros....

    But:

    When the sensor systems go wonky; when the control system has multiple failures; when the backups to the backups are failing and there's just a simple bit of logic left to define how the multiton clump of aluminum and flesh responds to the controls, the airplane has to do ONE thing: Fly like a Cessna 172.

    The way I understand it, most pilots, when stressed, revert to the reflexes needed to operate the plane they originally learned to fly on. Most probably learned on a 172 or aircraft of similar handling. Let the yoke move the airplane as if the pilot were in a Cessna. Let the airplane climb at its best rate achievable, let it provide plenty of simple control and audible warnings of decreasing speed, and not go shooting off in unexpected directions.

    Ron Wanttaja
     
  5. Oct 19, 2019 #285

    Wanttaja

    Wanttaja

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    After I posted this, I realized this is what we need: :)
    [​IMG]
    Ron Wanttaja
     
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  6. Oct 19, 2019 #286

    Himat

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    What to expect of pilots?

    A guess, pilots with average educational background and abilities. And probably as important, a large spread as there will be no “absolute” skill level required like in the selection of air force pilots in European countries, the US and Canada.

    Training to the minimum legal requirement by the lowest bidder. Expect the threshold to be what is possible to get away with.

    Differences in cultural background that may not be compatible with “western” thinking. At least what is “normal way to act” can not be taken as granted. That is something we are socialised into.

    The training issue you point as will come up again, there will be pilots that are trained to engage autopilot at a certain time and that is the way they are trained to operate the airplane. The autopilot is to be engaged for a prescribed part of the flight.
     
  7. Oct 19, 2019 #287

    TFF

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    Reality is this plane was designed for countries that have underdeveloped air systems and was supposed to fly auto pilot, auto land, CAT3 all the time. Hand fly is not what is supposed to happen. The experience level is not there so the plane is supposed to help the pilots. Take the US system out of the loop and it becomes clear that these guys flying in half the world could not take a 172 around the patch. They are picked to be pilots from status families to have status jobs. They are not motivated to be pilots. They are motivated to make their families happy. In countries that don’t have a lot of status direction it’s a big deal. Add to it putting junkyard parts on a plane to get it going, that just happens to be the major important information input puts it all in the what the heck category.

    Boeing is giving these countries what they want. There are plenty of wrong at the FAA and Boeing, but it was what the system was at the time. To make a profit you don’t do more than asked. It’s a plane for non pilots to fly. Remember take US out of the equation, it’s not meant for the US market. US pilots training puts them in a different category despite the flaws of design and regulations.
     
  8. Oct 19, 2019 #288

    Speedboat100

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    This is how the world sees it:
     
  9. Oct 19, 2019 #289

    davidb

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    The AirBus is as you describe. The 737 Max is not designed for the people you describe above. The first steps for nearly every minor system or environmental anomaly are to disengage the autopilot and auto throttle. 737 pilots must be trained and proficient at hand flying. The Max model is not a shift to more automation. The Max model changes are to account for the new engines with no changes to the automation that would help a pilot avoid the need to be proficient with “stick and rudder” skills.

    I’m not sure who’s to blame for placing this aircraft in the hands of the people you describe above, but if it’s done, a training program appropriate to the aircraft needs to be in place.
     
  10. Oct 19, 2019 #290

    BBerson

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    I thought the MCAS only activated after the autopilot was disengaged. (could be wrong o_O)
    Haven't been taking notes. I don't think anyone knows what happened yet. Will need to wait for the final report.
     
  11. Oct 19, 2019 #291

    davidb

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    We have a pretty good idea of what happened and we have been testing the typical crew response without pre-briefing the crews in the simulator.

    The scenario starts with a normal takeoff with no abnormal indications. During the rotation and liftoff, the faulty AoA sensor activates the stick shaker along with the various visual indications on the attitude indicator/flight director. It’s immediately obvious that these are false indications and the instinctual response is to fly a normal takeoff pitch attitude. The pilot then typically asks the other pilot what his indications are and his are normal.

    The next point of action occurs at 800 feet agl where we typically start to retract the flaps and accelerate to clean maneuvering speed. When the flaps are fully retracted, the unwanted MCAS trimming starts. Realize that we are actively changing the trim with the thumb switch during this phase of configuration and speed changes. Also, the speed trim function (it’s on all versions of 737 including the Max) is doing its thing to move the trim wheel. We subconsciously just move the thumb switch to keep it in trim usually vetoing the speed trim. This effectively masks and removes any unwanted trim from the MCAS. But, after a couple of cycles, it becomes apparent there is some sort of runaway trim situation. At that point, we turn off the electric trim and manually turn the wheel just like you do in a C172. The airplane never gets significantly out of trim and the autopilot never gets turned on.

    To get the results of the two mishap crews, you have to start with pilots not accustomed to hand flying. With the Lyon Air crash, the fatal turning point occurred when control was transferred to the right seater and he just let the trim run.

    With the second crash, the pilot kept trying to engage an autopilot that by design is inhibited and prohibited from use with his given indications. I’ll stop there.
     
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  12. Oct 19, 2019 #292

    BBerson

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    Ok, then the faulty AoA would only trigger MCAS before the pilot could put it on autopilot after takeoff.
    I don't see what those pilots supposedly did wrong, given that the flight manual they were given by Boeing didn't mention MCAS.
    And I just don't see that it is yet certain there was a faulty AOA vane that caused these crashes, since the AOA vane was replaced and it still crashed the next flight. Seems like a software problem that wasn't fixed. So I think I will wait till the final report, because the investigators have a lot to sort through. And I will stop also.
     
  13. Oct 19, 2019 #293

    plncraze

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    Thank you for those details davidb. These accidents combined with Boeing's issues are hard to understand without a pilot's perspective.
     
  14. Oct 19, 2019 #294

    Himat

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    Sellers, buyers and accountants.

    As I understand it, the 737 Max was Boings offering to take a share of the marked for airliners that size. The competitor to Boing was mostly Airbus. Then to be competitive Boings offering had to be at least marketed to be creating the same revenues to the buyer as the one from Airbus. A higher training cost for the crew would then not pass.

    I guess the 737 was then marketed as equal to operate as older 737 marks and have Airbus level automation.
     
  15. Oct 19, 2019 #295

    plncraze

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    I read "Growing Up Boeing" and all the pilots in the book retired from Boeing. The instant message guy took the fifth and is a first officer at an airline. He wanted out pretty badly.
     
  16. Oct 19, 2019 #296

    davidb

    davidb

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    It is the new engines that drove the market. These new engines are 20% more efficient...that’s a huge leap (pun intended). They fit nicely on the A320 series because it has taller landing gear. Boeing had to make this new engine work on the 737 to compete with the new engined A32X lest AirBus would monopolize the market for this size aircraft.

    The Max isn’t marketed as an automation leap, rather an efficiency leap for carriers already flying 737s. Changing fleets is expensive for carriers but they would do it for the 20% efficiency boost if there wasn’t a Boeing option.
     
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  17. Oct 20, 2019 #297

    12notes

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    Boeing was kind of forced to make the 737 MAX by American Airlines. Boeing had not decided whether to modify the 737 or start with a clean sheet design, the CEO stated in February of 2011 "We're going to do a new airplane." But, in July of 2011, American announced that they were buying 130 Airbus A320s & 130 A320neos (their first ever Airbus purchase) and 100 737s and 100 of the "re-engined 737".

    "American also intends to order 100 of Boeing's expected new evolution of the 737NG, with a new engine that would offer even more significant fuel-efficiency gains over today's models. American is pleased to be the first airline to commit to Boeing's new 737 family offering, which is expected to provide a new level of economic efficiency and operational performance, pending final confirmation of the program by Boeing. "

    Although not literally forced, it's really hard to turn down a roughly 7 billion dollar order. So the new plane design was killed and the 737 MAX was started at the end of August, 2011.

    This contains a valuable lesson for engineers about the dangers of telling the salespeople about what you're working on. They'll sell it before you even decide if it's a good idea.
     
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  18. Oct 20, 2019 #298

    bmcj

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    C3808495-1136-4E92-83CF-4ABB8CCDF8EC.gif
     
  19. Oct 21, 2019 #299

    BJC

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    I worked for a regulated electric utility company. Everything that we did was subject to regulatory review, by both state and federal agencies. We were free to delete emails, because they were automatically saved by the server.


    BJC
     
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  20. Oct 22, 2019 #300

    trimtab

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    The ballscrew system employed in the 737 has been problematic for decades.

    https://www.federalregister.gov/doc...thiness-directives-boeing-model-737-airplanes

    The torque required to turn the ballscrew assembly has been a problem for as long as the 737 has been in existence, as evidenced in the POH's. Make no mistake, the procedure in the POH is probably useless during the critical departure phase.

    To call this issue equivalent to a mere pilot mistake is a departure from safe or reasonable standards of engineering. The engine fire example is a pretty good example. To compare certification standards for GA to transport category is a misfire. Transport category fire detection and suppression systems are a pretty large, important, difficult element of powerplant integration and certification. The possibility that the scenario could happen for a transport TC is vanishingly small, even absent direct cockpit interventions on many powerplants (the FADEC for the F-135, for example, activates a total lock down when certain events occur, some of which are related to fire events). The engine failure example is another poor comparison given the propulsion redundancy requirements for transport category aircraft. In addition, in the event of failure of all engines, control of the aircraft is (gasp!) mandated in every TC following the total engine failure(s).

    Let's invent some new scenarios: flap speeds. The issues may be structural damage for overspeeds (possible). There are placards and airspeed indications for these types of things. More often, the limits are based more on maneuvering speed limits than wing structural issues, but they are both taken into consideration. But there are clear placards and indications. No such training, placards, or other indications exist for out of trim conditions in the 737..

    I would not fly in an aircraft for which normal maneuvers executed at appropriate placarded or otherwise displayed airspeeds with any amount of laziness or lack of skill would potentially induce structural failure or cease operation of a primary flight surface in an unrecoverable manner when a single sensor fails.

    I don't think the flying public should be expected to do so, either.

    That is a departure from what happened in the case of the stiff jack screw. The distinctions here are very real, and not subtle at all to a person who is used to making these judgments.
     
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