Illustration of <a href="https://en.wikipedia.org/wiki/Airway_beacon" class="extiw" title="en:Airway beacon">Airway beacon</a>. Original uploader was <a href="https://en.wikipedia.org/wiki/User:Crum375" class="extiw" title="en:User:Crum375">Crum375</a> at <a class="external text" href="https://en.wikipedia.org">en.wikipedia</a>
U.S. DOT <a href="https://en.wikipedia.org/wiki/FAA" class="extiw" title="en:FAA">FAA</a>.
<a rel="nofollow" class="external free" href="http://www.centennialofflight.gov/essay/Government_Role/navigation/POL13G6.htm">http://www.centennialofflight.gov/essay/Government_Role/navigation/POL13G6.htm</a>