LEGS Not Advancing

[Mandretti]

I have an 8 page flight plan and the CDU is stuck highlighting the first leg.  If I remember correctly the highlight is supposed to advance to the active leg as the aircraft is making its way through the plan.  I think in previous flights it's worked correctly, and I'll check this out.  But just wondering if there is some setting or circumstance that I should be aware of that could cause this.  

The flight plan is being executed properly; VNAV, LNAV and IAS.  

 

thanks. 

Edited February 10, 2022 by Mandretti

[Litjan]

Hello Mandretti,

the most probably cause is that you passed the "active" waypoint at a distance of more than 2.5 nautical miles.

This can happen when you do not fly on LNAV and simply fly past it too far abeam - but it can also happen when the speed of the aircraft is high and the turn angle acute - which makes the FMS calculate an intercept turn that "flies by" the actual waypoint...and sometimes too far.

This second behavior is something that we still want to fix, as the real plane does not skip the sequencing when on LNAV (and just misses the point by its own "fault").

To cure this when it happens just click on the next point you want to fly to (this will copy it into the scratchpad) then click on the top left Line Select Key to insert this waypoint, this will effectively tell the FMS to navigate DIRECT TO that waypoint.

Cheers, Jan