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Thread: Somatogravic illusion. Recent hot button question on check-rides.

  1. #1
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    Default Somatogravic illusion. Recent hot button question on check-rides.

    The FAA seems to wander through various hot-button topics they want examiners to ask about during check-rides. In the past we had controlled flight into terrain,{CFIT}, and the Risk Management matrix..

    Yesterday one of my private pilot clients was hit up with Somatogravic illusion during his oral.... Which of course sent his brain right off the rails. Although in a way he really knew the answer....or at least part of it...

    1. The part he did know: Examiners often have the student under the hood and then tell them to close their eyes and put their head down while the examiner yanks the plane around in weird gyrations. Then the examiner tells the student to open their eyes and jerk their head up while taking control of the plane. In this case the sudden jerking up of the head screws up the inner ear and gives the student vertigo as they try to control the plane and regain level flight. In this case there is no valuable input from your eyes to tell you what is really going on.. ( That is why I tell my clients to slowing bring up their head to avoid the vertigo sensation during their check-rides.)

    Well anyway, you can do the same thing to yourself during night flight during acceleration or deceleration.


    Somatogravic Illusion


    Instrument Flying Handbook Menu>Human Factors>Illusions Leading to Spatial Disorientation>Somatogravic Illusion

    A rapid acceleration, such as experienced during takeoff, stimulates the otolith organs in the same way as tilting the head backwards. This action creates the somatogravic illusion of being in a nose-up attitude, especially in situations without good visual references. The disoriented pilot may push the aircraft into a nose-low or dive attitude. A rapid deceleration by quick reduction of the throttle(s) can have the opposite effect, with the disoriented pilot pulling the aircraft into a nose-up or stall attitude.

    https://www.youtube.com/watch?v=_oc_52gnrv8

    https://www.youtube.com/watch?v=ifpUD9Iteow

    http://aviationknowledge.wikidot.com...ravic-illusion

    http://www.skybrary.aero/index.php/S...d_Somatogyral_
    Floatplane,Tailwheel and Firearms Instructor- Dragonfly Aero
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    Interesting stuff. I was just explaining that same thing to my wife when we flew outside a few weeks ago. The effect is quite noticeable when you're in the back of the 737 and it appears to pitch up as soon as it begins to accelerate....Louis
    Louis Knapp

  3. #3

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    I am fortunate that I have never had these effects, my instructors tried it numerous times when I was under the hood and I was able to recover quickly. That probably made things exponentially easier for me going into acro. I thought about getting my instrument rating but my plane has no instruments for instrument flying.

    I am sure that term is in the large hard back instrument flying book. During my check ride I did not feel like there was any hot button stuff, he went through the whole range of questions in both the oral and practical.

  4. #4

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    The mindset of an instrument pilot can be a benefit to many VFR pilots. I would strongly encourage anybody reading this to consider the full range of benefits rather than whether they will be conducting instrument flight in their personal plane.

    Instrument flight encourages the pilot to think far ahead of the airplane and evaluate conditions far ahead of the airplane. There honestly is not a downside other than cost.
    14 Days to Alaska
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    I'm still a smoker. When I bought my new TU206 amphib, the ash tray had been moved from the windshield ledge to the fuel selector pedestal, a very, very poor place. Both for possible fire on account of a leaky selector valve, and for the near-the-floor location of the ash tray itself. Vertigo in the making. I called Cessna and told them that such a location was a real mistake, and gave them my reasoning. I don't know whether or not they've done anything about it . . . . .

  6. #6

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    Though its not much cost to get all the ground school materials and just get a little training here and there when you go up with buddies who have instrument rated planes and who are instrument rated.

    Quote Originally Posted by Troy Hamon View Post
    The mindset of an instrument pilot can be a benefit to many VFR pilots. I would strongly encourage anybody reading this to consider the full range of benefits rather than whether they will be conducting instrument flight in their personal plane.

    Instrument flight encourages the pilot to think far ahead of the airplane and evaluate conditions far ahead of the airplane. There honestly is not a downside other than cost.

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    Gee, rppearso, you make it all sound so very simple . . . . .

  8. #8

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    It is simple just not easy. I talked to my instructor and he said it woudl make me a little mroe well rounded but for teh time and money involved it woudl not be worth it if all I fly is a non instrumented plane.

    Quote Originally Posted by Grizzly 2 View Post
    Gee, rppearso, you make it all sound so very simple . . . . .

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