Cockpit error sent 737 into Pacific nose dive

Discussion in 'Other Aspects of Aviation Security' started by THawk996, Sep 29, 2011.

  1. THawk996

    THawk996 Original Member

    From the CBS News web site:
    Cockpit error sent 737 into Pacific nose dive

     
  2. RB

    RB Founding Member

    Ok, I'm not the sharpest hoe in the shed but I think I could tell rudder pedals from a door knob.
     
  3. FriendlySkies

    FriendlySkies Member

    Oops... Hope that doesn't happen on my ANA flight in January! :eek:
     
  4. FetePerfection

    FetePerfection Founding Member Coach

    That co-pilot must be a door knob.
     
  5. Mike

    Mike Founding Member Coach

    I think the news agency (ANA) got some wires crossed. Rudder controls are only useful at low speeds, usually on the runway. The copilot must have done something much dumber. The actual report should be interesting.
     
  6. myadvice

    myadvice Original Member

  7. FetePerfection

    FetePerfection Founding Member Coach

    While I don't understand Japanese I certainly could understand the graphics and all I can say is holy :trash: & throw a little :vomit:in there for good measure.
     
  8. Leave no trace

    Leave no trace Original Member

    I think they said "the 737 is not certified for aerobatics".
     
  9. Mike

    Mike Founding Member Coach

    Tell me that's not true! I want to see them in an air show. :)
     
  10. Leave no trace

    Leave no trace Original Member

    Sadly, even my fertile imagination cannot stretch so far as seeing the red arrows aerobatic team performing in 737's :)

    But if I hear of such an event, you will be the first to know.
     
  11. Mike

    Mike Founding Member Coach

    Tex Johnson might have been up for it but he got smacked down in "training". :(
     
  12. THawk996

    THawk996 Original Member

  13. RB

    RB Founding Member

  14. Leave no trace

    Leave no trace Original Member

    Hmm, you might be right on that, I guess that the word RUDDER is a clue.
     
  15. RB

    RB Founding Member

    When I first looked at the control I thought it might be rudder control for the autopilot but looking at the other nearby controls I believe it is Rudder Trim which is entirely different than direct rudder control.

    Don't know what you know about aircraft but trim tabs are used to take force off of the controls so the pilot feels a more balanced weight on the yoke. It would take a lot of trim tab movement to make the aircraft behave as reported so I think something is missing in the report. In fact direct rudder input by the pilot would overcome the trim setting although the pilot would experience a very heavy control feel.
     
  16. THawk996

    THawk996 Original Member

    I am unfamiliar with a cockpit layout, but above the knob labeled "RUDDER" is a gauge that appears to be labeled "RUDDER TRIM" (though the "RU" is cropped out of the photo). Presumably turning the knob would produce some change in the gauge.

    Based on the proximity of the two knobs, I can see how an inattentive or distracted co-pilot could turn the wrong knob. As to whether this would cause the plane to do a near barrel roll, I have no idea.
     
  17. Mike

    Mike Founding Member Coach

    Rudder trim is used normally to compensate for other malfunctions that cause the plane not to fly in a straight line, e.g. engine shutdown, defective flap dragging. If he just snapped it over as though it were the door lock knob, he immediately set it to a very high degree of rudder trip for an airplane in flight at 500+ MPH.

    By itself that should not cause the plane to roll if the plane were otherwise perfectly trimmed and level, but think of the aerodynamic forces at 500+ MPG once your wing is out of trim (up or down) and the tail is trying to move to one side. Suppose the wing dips -- you now have the wing being pushed down & the rudder trying to pull the rear end of the plane up & over the wing.
     
  18. RB

    RB Founding Member

    Mike, I don't know how much stick time you have but flight control trims are used to neutralize the stick and rudder forces so the control force is reduced to near zero. You can liken it to holding pressure to keep the aircraft from moving in a certain direction, trim is introduced to balance out that force.

    I agree that all airplanes are not perfectly in trim, especially at different air speeds and control configuration. Example, some aircraft after the gear is extended take a fairly large elevator trim correction to re-balance the stick, otherwise the pilot is having to use a fair amount of force to hold the nose of the aircraft at the desired pitch. Small aircraft usually only have elevator trim while larger aircraft will have trim tabs on all three flight axis controls.
     
  19. Mike

    Mike Founding Member Coach

    On multi-engine aircraft, rudder trim is negligible under normal operating conditions. You accomplish the same thing by adjusting engine thrust without increasing drag & fuel consumption.
     
  20. Mike

    Mike Founding Member Coach

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