...Now, a question about navigation equipment ...
1 aircraft is fitted with an SPZ 7600 DAFCS (AHRS/EFIS)
2 LNAV coupled to FMS (UNS1)
3 heading is not synchronized with the flux valve (in DG or because of any other disturbance) so that the EHSI set in "route mode" displays a false heading, showing therefore a uncorrectly oriented route.
Untill now, my experience (based on Garmin 530W and not on a true FMS) tells me that the FD will follow the coupled source, in this case the GPS great circle segment between 2 WPs, and this, whatever the indicated heading ( indicated wind and GS will be wrong in this case)
But a colleague, more familiar with the UNS1 is sure of the opposite i.e the FD will follow the displayed route wich in this case is wrongly oriented resulting in an actual route deviation .
Any return of experience or idea ?