ILS Sensitive Areas RNAV
When category II and category III ILSILS —Instrument Landing System operations are ongoing, any interference with the guidance signal needs to be minimised, owing to how close landing aircraft on these types of approach will get. As a consequence, movement of vehicles and aircraft will be prohibited in the critical area and restricted (by ATCATC —Air Traffic Control) in the sensitive area.
For the sensitive area, whether you are allowed to enter will largely depend on the size of your aircraft. A light Cessna might be permitted; an Airbus A380 would probably not. Note there is no need for these areas to be active if Cat II/III operations are not ongoing.