GPS II vs GPS III logs

  • Hello Richard,

    I bought a GPS III to replace a GPS II with which I occasionally lost data.

    The GPS III is supposed to be more precise.

    The GPS is installed on a Mercury powerbox.

    Attached are two examples of Data logs recorded with Futaba telemetry on the same model and at the same position.

    With the GPS III it is worse and the loss of data is almost permanent.

    Is it due to a product defect?

    Is the mercury gyro affected by the loss of speed data?

    Best regards.


    Data logs

  • Hello,

    The GPS is installed under the canopy. Attached is the photo of the installation.

    I have a second new GPS III for another aircraft.

    Before I send this one back to you for replacement, I'll test the second one to see if the problem is the same.

  • Hello Richard,

    Continuation of my tests.

    I moved the GPS III far away from any electronics or cables in the nose of the plane.

    I still have the same problems with both GPS IIIs.

    Attached is a data record.

    Orange cells = frozen speed data

    Red cells = loss of data and bad GPS coordinates.

    I have absolutely no confidence in flying with the GPS III.

    If the Mercury receives the wrong speed indication, there is a risk that the gyro gain will not be reduced at high speed with my jet.

    I will return the GPS IIIs to you for repair or replacement.

    Flight GPS