Disagreeing Flight Directors - A320
 

G'day All,

Just wonding if anybody would be able to shed some light.

On departure, GPS primary. No FM/GPS disagree. FMGC syncronised, Captain FD indicates a turn to intercept, FO FD is still squared for a few moments then begins to indicate the turn.

I have seen this usually during climb. One FD may indicated a different target attitude than the other.

Can anyone shed some light on what might cause this?

Disagreeing FD Bars in the A320 series - seen mainly in descent - is the result of slightly different calculations between FMGC 1 and 2. The autopilot will of course satisfy the FD demands allied to the engaged autopilot and thus the PNF will see the FD discrepancy.

Hope this helps,
mcdhu

Thanks for that. I've never seen it when calculating a lateral flight path though. Thought it was a bit strange.