ABSTRACT
ILS remains installed throughout the world and is
the basis of automatic approach and landing for
many aircraft types. Limitations of ILS are the
single approach paths from the glide slope and
localizer; this can be a problem for airfields
located in mountainous regions. Furthermore, any
vehicle or aircraft approaching or crossing the
runway can cause a disturbance to the localizer
beam, which could be interpreted by the airborne
equipment as an unreliable signal. This often
causes an AFCS channel to disconnect with the
possibility of a missed approach. The local terrain
can also have an effect on ILS performance, e.g.
