Editing Instrument landing system (section)

===Monitoring===
It is essential that any failure of the ILS to provide safe guidance be detected immediately by the pilot. To achieve this, monitors continually assess the vital characteristics of the transmissions. If any significant deviation beyond strict limits is detected, either the ILS is automatically switched off or the navigation and identification components are removed from the carrier.<ref name="frs2001">{{cite web | author=Department of Transportation and Department of Defense | date=March 25, 2002 |url=http://www.navcen.uscg.gov/pdf/frp/frp2001/FRS2001.pdf | title=2001 Federal Radionavigation Systems | access-date=November 27, 2005 | url-status=live | archive-url=https://web.archive.org/web/20110614015708/http://www.navcen.uscg.gov/pdf/frp/frp2001/FRS2001.pdf | archive-date=June 14, 2011 }}</ref> Either of these actions will activate an indication ('failure flag') on the instruments of an aircraft using the ILS.