A perspective drawing of a boomerang antenna of the type used on aircraft.
<a href="//commons.wikimedia.org/wiki/User:Noha307" title="User:Noha307">Noha307</a>
<span class="int-own-work" lang="en">Own work</span> created with <a href="https://en.wikipedia.org/wiki/Inkscape" class="extiw" title="w:Inkscape">Inkscape</a> based on <a rel="nofollow" class="external text" href="http://babel.hathitrust.org/cgi/pt?id=mdp.39015039968444&amp;seq=29">manual page</a>