Assertion: marker | /r/HasProperty | become limited
Facets:
value: to ils approach installations
type: TRANSITIVE-OBJECT
value: from the 1960s
type: TEMPORAL
value: increasingly
type: DEGREE
Source sentences:
text: From the 1930s until the 1950s, markers were used extensively along airways to provide an indication of an aircraft's specific position along the route, but from the 1960s they have become increasingly limited to ILS approach installations.