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Thread: Breaking news: Ethiopian Airlines flight has crashed on way to Nairobi

  1. #361
    Senior Member Evan's Avatar
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    Quote Originally Posted by BoeingBobby View Post
    The difference between the 747-400 and 747-8 are not that much different than the difference between the 737 NG and the MAX
    Really? So what happens to a pitch trim runaway on the 747-8 when you pull against it with the control column?

    Please don't say "nothing", or we are going to have a much bigger story on our hands....

  2. #362
    Senior Member BoeingBobby's Avatar
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    Quote Originally Posted by Evan View Post
    Really? So what happens to a pitch trim runaway on the 747-8 when you pull against it with the control column?

    Please don't say "nothing", or we are going to have a much bigger story on our hands....
    You just keep proving my point Evan. You know that the MAX is the first A/C with the MCAS system. But you also spoke out of your rear end (for a change ) when you infer that the only difference between a 747-400 and the -8 is a stretch of the fuselage. Not only are the electronics much different, but it has the new type ECL, flare assist, flaperons and FBW spoilers. Difference training in a day. What are your qualifications?

  3. #363
    Senior Member Evan's Avatar
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    Quote Originally Posted by BoeingBobby View Post
    You just keep proving my point Evan. You know that the MAX is the first A/C with the MCAS system. But you also spoke out of your rear end (for a change ) when you infer that the only difference between a 747-400 and the -8 is a stretch of the fuselage. Not only are the electronics much different, but it has the new type ECL, flare assist, flaperons and FBW spoilers. Difference training in a day. What are your qualifications?
    Forget about the 747-8. Hear me out for once, because you're not getting a very important distinction here regarding the NG-to-MAX transition. Every modern Boeing that I'm aware of (727,737,757,767,777 - not 100% sure on the 787) has had a function whereby the pitch trim will stop if you pull the column against it. This adds safety by providing an instinctive means of stopping an electrical trim runaway (or mechnical runway on the ones that use a stab brake) and is a learned methodology that has existed for five decades, including on the NG. But, in order to provide the MCAS system, which actually uses stabilzer trim to counter pilot pitch commands, that function had to be quietly removed. AFAIK, -MAX pilots were not informed of this change. Don't you think that's a significant issue? Don't you think, when the function of the primary flight controls change, that it warrants a new sim? Don't you think pilots doing upset training involving a pitch trim runaway on a sim where pulling up DOES cancel the trim for an aircraft where it DOESN'T is a bit unwise? And don't you think a full-motion sim should be provided for upset training?

    Back in the early 1960's there was a 707 crash where the pilot was caught in an updraft and reacted by applying both full downward elevator and full AND stabilizer at an altitude of around 19,000ft. There was no further corrective action taken for a critical eight seconds, by which time the plane was in a steep dive, aerodynamic forces prevented the stabilizer from responding to commands and the elevator was unable to overpower it. The plane crashed into the Everglades in a near-vertical dive just 45 seconds after the initial upset. The investigation concluded that the eight-second delay was due to the pilot being thrown away from the controls by the ensuing g-forces. Now, I realize that you cannot recreate that level of extreme force in the sim, but, as g-forces DO play a factor in abrupt upsets, don't you think it would be unsafe to exclude any motion awareness from the exercise?

  4. #364
    Senior Member Gabriel's Avatar
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    Quote Originally Posted by Evan View Post
    Do you mean negative training? Because that is what training for an MCAS runaway on an NG simulator amounts too.
    Ok Evan, yes, Boeing screwed it up with the MCAS. But trim runaway training in the 737-200 -Adv (or in the 707 probably too) is NOT negative training for the MAX.

    Questions:

    - Will operating the thumb trim switch override any automation input over the trim, therefore stopping the automated motion and letting you trim however you want?
    - Will switching the cutout switches to cutout stop the automatic motion?
    - Will grabbing the wheel if necessary stop the trim motion even if the trim motor keeps spinning?
    - Will turning the wheel manually move the stabilizer to trim however you want?
    - Are all of the above actions part of the trim runaway procedure?
    - Does the trim runaway procedure includes using the control column to stop the trim runaway?
    - Does the answer to any of the above questions change depending on whether the 737 is a -100, -200, -200Adv, -300, -400, -500, -700, -800, -900, -MAX8, -MAX9 or -BBJ?

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  5. #365
    Senior Member BoeingBobby's Avatar
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    You don't seem to grasp it do you? Do I need to type in a colored font or something? It can be in a Sim that is an NG, probably an 800 too. The Sim does not and I will repeat it so maybe it will sink in, does not need to be type specific.

  6. #366
    Senior Member BoeingBobby's Avatar
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    "Every modern Boeing that I'm aware of (727,737,757,767,777 - not 100% sure on the 787) has had a function whereby the pitch trim will stop if you pull the column against it".

    Well I have never flown a 72,73,75,76 or 777. But I have flown the 707, 720 and every model of the 747 except the SP, and none of them do what you are saying above. Trim running away, the rocker switches in the yoke will stop it until you let them go. The procedure is to hold the switches in the opposite direction of the runaway and turn the system off with the stab trim cut out switches. Where you come up with the shit you post is unbelievable.

  7. #367
    Senior Member Gabriel's Avatar
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    Quote Originally Posted by Evan View Post
    Forget about the 747-8. Hear me out for once, because you're not getting a very important distinction here regarding the NG-to-MAX transition. Every modern Boeing that I'm aware of (727,737,757,767,777 - not 100% sure on the 787) has had a function whereby the pitch trim will stop if you pull the column against it. This adds safety by providing an instinctive means of stopping an electrical trim runaway (or mechanical runway on the ones that use a stab brake) and is a learned methodology that has existed for five decades, including on the NG.
    I preliminary* call that BS. Not that the function doesn't exist, it does, but as I understand it:
    - It will work only for certain types of trim runaway, not all of them.
    - It is designed not as a way of stopping the trim runaway, but as a mean to avoid having the pilot pulling one way and the AP pulling the other way.
    - There is no trim runaway procedure that calls for pushing/pulling against the trim as a way to stopping the runaway. If that is what have been trained and practiced, then THAT is negative training. And there is no such thing as "learned methodology" outside of training, since by large most pilots die (hopefully of natural causes) without ever experiencing a real trim runaway out of a training environment, and I men ever, not only in a particular type, but since hour zero in a C-150.

    * preliminary because it is "as I understand it" and I am not fully confident of my understanding here.

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  8. #368
    Senior Member Evan's Avatar
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    Quote Originally Posted by BoeingBobby View Post
    Where you come up with the shit you post is unbelievable.
    FCOM's, NASA contractor reports

    Gabriel:

    Quote Originally Posted by Gabriel
    Not that the function doesn't exist, it does
    I'm not saying that this function is intended as a procedural action to pitch trim runaway. I've never seen this in any procedure.
    I'm saying it is a primary instinct that cancels the pitch trim (or runaway, if the runaway is electrical).

    I suppose I should have said "instinctive methodology" rather than a "learned" one. But you cannot ignore the larger point here. The MAX doesn't behave the same way as every previous Boeing has in this respect. Pilots were not told about this.
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  9. #369
    Senior Member brianw999's Avatar
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    And what does all this mean for the paying public ?
    Well, for me it means not booking two holiday flights that were supposed to be operated with 737 MAX airframes and booking with another airline that operates Airbus airframes.

    TUI Airways loss, British Airways gain.
    Last edited by brianw999; Today at 07:20 PM.
    If it 'ain't broken........ Don't try to mend it !


  10. #370
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    Transportation Secretary Elaine Chao has asked for a formal audit of FAA's approval of Boeing 737 Max 8 planes.

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