FMC got stuck on missed waypoint, but plane still followes LNV

[MelCologne]

Today i tried a crazy route, and got a strange behaviour from the FMC.

(EDDK 14L) PODI1X PODIP Y867 BADGO Z850 HMM/N0426F330 M170 OSN UM170  BASUM Z78 WSN/N0429F320 UN125 EEL DCT (EDWR 31)

The plane missed the waypoint BADGO by about 2.5nm in a turn.
While it is still following the LNAV path, the FMC on the LEGS and PROG page got stuck saying that BADGO is the next waypoint.

On my first flight i was already at OSN, so i was a little bit confused when i checked the LEGS page.

[Litjan]

We will need to add some code to make the FMS not "miss" sequencing a waypoint when it passes it by more than 2.5NM (in LNAV). The LNAV is following the magenta, it has no idea about waypoints - hence the discrepancy.

Jan

 

[MelCologne]

Sounds hard to get LNAV and FMC waypoints really in sync.
Setting the distance too high, could have other side effects.

I think the waypoint should then only be marked as done, when the distance starts increasing and the course of the aircrafts roughly points to the next waypoint.
Would be interesting to know how the real FMC handles such near misses and to which direction the aircraft would steer, when the waypoint was missed.
I am sure even on the real plane the programmers had a hard time getting this work. 

[volkerschwarz]

hello melcologe, same in Frankfurt waypoint KRH in a turn. I hoped that the update stopped this issue.

regards Volker