plural of personal locator beacon

plural of emergency locator transmitter

plural of central location test

plural of Uniform Resource Locator

(aviation, chiefly US) A ground-based radio navigation aid consisting of a pair of colocated radio beacons at the final approach fix of an ILS or IGS approach course: an NDB to guide aircraft to the approach fix, and an outer marker to alert aircraft as they pass over the station.

plural of locator outer marker