This is off the subject;  but can you tell me if it necessary
to both set the AP mode switch to TACAN  AND use the FSX keyboard command ( Ctl+Shf+n ) to
enable the BUFF to follow the FSX flight plan.  Or should
the plane follow the FSX flight plan by simply setting the
AP Mode Sw to "TACAN" ?   Does the Flight Director
switch on the Pilot's control panel also need to be set
to the FD position for the Buff to follow the FP.
  Simply setting the AP Mode Sw to "TACAN" hasn't
worked for me.
Best regards,
Ken