Strange Issue with VNAV during Climb (B777)

  • Hi Jan,

    it's me again. I discovered a strange issue with VNAV during climb phase:

    Shortly after take off the T/D moves towards

    the position of my plane, putting itself ahead of T/C.

    This causes VNAV PTH to engage during climb:

    B777 | VNAV Issue during Climb
    VNAV PTH engages during climb due to T/D moving ahead T/C

    This time my route was:

    After the T/D had passed me - I had just taken off -
    I could reengage VNAV SPD.

    It almost seems as if there was an additional false T/D...


    Update: It now makes sense to me that VNAV PTH engages due to the ALT constraint
    (4000A 7000B). Is it correct though that the T/D moves through me?

    Edited 3 times, last by Mr_Smith (January 20, 2023 at 11:18 PM).