an FMS approach is based on information in it's own database, some provide lateral and vertical guidance, others only lateral...the 767 was different as the ILS could be tuned independently with the tuner on the centre pedestal as I remember, since this particular approach is offset, manually tuning the ILS was probably not a part of their SOPs, it is possible in the Airbus, but generally only used during downgrading of the FMGS system...the FMS approach is displayed as an LNAV track on the nav display..