a) The ILS Critical Area.
b) The ILS Sensitive Area.
(In some states the term “critical area” is used to include the
above sensitive area also).
6.1.7 ILS Critical Area. (see diagram on page 47) The ILS Critical Area is an area of defined dimensions about the localizer and glide path antennas where vehicles, including aircraft, are excluded during all ILS operations. The critical area is protected because the presence of vehicles and/or aircraft inside its boundaries will cause unacceptable disturbance to the ILS signal in space. To protect the critical area, it is necessary to prohibit all entry of vehicles and the taxiing or parking of aircraft within this area during all ILS operations. The critical area for each localizer and glide path should be clearly designated. Suitable signal devices may need to be provided at taxiways and roadways, which penetrate the critical area to restrict the entry of vehicles and aircraft.
6.1.8 ILS sensitive area. (see diagram on page 47) The ILS Sensitive Area is an area extending beyond the critical area where the parking and/or movement of vehicles, including aircraft, is controlled to prevent the possibility of unacceptable interference to ILS signal during ILS operations.
The sensitive area is protected against possible interference by large moving objects outside the critical area bur still normally within the airfield boundary. The size of a sensitive area depends on a number of factors including the type of ILS antenna, the topography, and the size and orientation of man- made objects, including large aircraft and vehicles. Modern designs of localizer and glide path antennas can be very effective in reducing the disturbance possibilities and hence the extent of the sensitive areas. Because of the greater potential of the larger types of aircraft for disturbing ILS signals, the sensitive areas for these aircraft extend a considerable distance beyond the critical areas. The problem is aggravated by increased traffic density on the ground. It may be necessary to exclude some or all-moving traffic from a sensitive area depending on interference potential and category of operation. It would be advisable to have the aerodrome boundaries include all the sensitive areas so that adequate control can be exercised over all moving traffic to prevent unacceptable interference to the ILS signals. If these areas fall outside the aerodrome boundaries it is essential that the co-operation of appropriate authorities be obtained to ensure adequate control. Operational procedures need to be developed for the procedures of sensitive areas. 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：CAT II/ III A/ III B TRAINING MANUAL 培训手册(15)
