相关题目
（ ） is a n LF/MF NDB used as an aid to final approach.
（ ） is a runway that is unusable for aircraft operations.
（ ） is the component of an ILS which provides course guidance to the runway.
（ ） is the ratio of true airspeed to the speed of sound.
（ ） is a specified area within or over which there may exist activities constituting a potential danger to aircraft.
（ ） is an area of defined dimensions within which the military training activities conducted, though not hazardous, are of interest to non-participating pilots.
（ ） is routine broadcast of meteorological information for aircraft in flight.
（ ） is a non-government air/ground radio communication facility which may provide air port advisory service at certain airports.
（ ） is the lowest flight level available for use above the transition altitude.
（ ） is the actual flight path of an aircraft over the surface of the earth.
