Editing Automatic direction finder (section)

===Station passage===
As an aircraft nears an NDB station, the ADF becomes increasingly sensitive, small lateral deviations result in large deflections of the needle which sometimes shows erratic left/right oscillations.<ref>{{cite book | last=Tait | first=Bob | title=CPL Navigation | location=Archerfield, Queensland| publisher=Bob Tait's Aviation Theory School | year=2008  | oclc=224434684}}</ref> Ideally, as the aircraft overflies the beacon, the needle swings rapidly from directly ahead to directly behind. This indicates ''station passage'' and provides an accurate position fix for the navigator. Less accurate station passage, passing slightly to one side or another, is shown by slower (but still rapid) swinging of the needle. The time interval from the first indications of station proximity to positive station passage varies with altitude — a few moments at low levels to several minutes at high altitude.