Wing angle of incidence

Hi, I have just treated my C182RII to a Garmin TXI500, GNS750 and a new garmin autopilot.. I am feeling poor. However the aircraft is now indicating it is flying nose down on the AH but flying level by the altimeter and auto. Has someone fiddled with my wing angles? I have had the installation checked and both G5 and TXi are consistent. Any thoughts would be appreciated. Steve

Comments

  • Scott ShererScott Sherer COO Forum Moderator

    Hi Steve, very interesting problem. I'm going to forward this to our A&P, Erich Rempert. Please stand by.

    Scott Sherer
    Wright Brothers Master Pilot, FAA Commercial Pilot
    Aviation Director, Cessna Owners Organization Forum Moderator and Cessna Owners Author.

    Need help? Let me know!

  • Scott ShererScott Sherer COO Forum Moderator

    Here's a reply from our A&P Erich Rempert:

    Per the installation manuals the symbolic aircraft is set to true level with the waterline of the aircraft (all installations).

    The truth is the airplane likely flies slightly nose low, (or the unit was not calibrated correctly).

    Old mechanical gyros allowed the setting of the symbolic airplane wherever the pilot wanted (on the horizon usually) and thus nulling out any percived error.

    Of course the airplane usually flies at some other pitch angle rather than zero, and that's what you are seeing. A standard Navion, and the Swift are a couple examples of airplanes that fly "nose low" in comparison to the aircraft "waterline".

    To verify proper calibration, level the aircraft per the leveling instructions, turn the system on and see where the symbolic airplane sits on the AI, it will likely be right where its supposed to be.

    You or your normal Mechanic can perform this test, if you find it is in error, bring the airplane back to the Avionics installer and have it corrected under warranty (or have them come to the airplane if its already level).

    After the symbolic airplane is properly set it will depict the actual pitch of the aircraft vs the horizon and the waterline.

    In the user options there may be a setting that can be changed to adjust the symbolic airplane up or down, but there might not be. If there is, go fly in smooth air on altitude hold and adjust the symbolic airplane down to the horizon. If there isn't you will need to learn the normal flight attitude of the aircraft under different circumstances and mentality adjust.

    But I assure you, the wing angles have not changed.

    ~Erich Rempert, IA Consultant

    Scott Sherer
    Wright Brothers Master Pilot, FAA Commercial Pilot
    Aviation Director, Cessna Owners Organization Forum Moderator and Cessna Owners Author.

    Need help? Let me know!

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