"RESYNCING OTHER FMC" ?

[cagarini]

Today, while starting a situation I have for takeoff from LPPT 21, I got this MCDU "RESYNCING OTHER FMC" and an Upper EICAS > FMC notification.

Had never seen it before. After a while it was gone, before I could perform a screen capture :-/

What might have caused it ?

And, btw, while searching for any Internet hints, I found this funny one:

https://www.quora.com/Does-Boeings-FMC-or-Airbus-FMGC-have-programming-bugs

[Hardy Heinlin]

The other FMC has lost power and is now repowered and is now getting data from the master FMC so that both FMCs can operate with the same data. Or you loaded an FMC route file that included invalid data and the FMS is now cleaning its route memory. The latter can only happen in PSX as the real FMC doesn't work with add-on generated route files.

Screen captures don't help. Situ files help. Just press the EVENT REC button above the upper EICAS.

[cagarini]

Thx HH,

the "strange" thing is that is the very same SITU I always have loaded, and it starts with the aircraft holding to the left of the RW threshold, ready to line up... and I had never seen that message before.

Is there any random factor in it?

[Hardy Heinlin]

No random. There are two possible logical causes as described above, and the effect is intentional.