What do you mean by "airfield safeguarding measures", a fairly generic term covering for example masts and chimneys within a radius of some miles from the ARP? If Cat 1 ILS protection (LOC and G/P Critical Areas etc) is not in place, no, you can't land. If Cat 2 protection, ie LVPs, is not in place, then, depending on your Ops Manual, you can land.
[ 29 January 2002: Message edited by: Hew Jampton ]</p>