11th Observation Sq emblem.  Approved 26 October 1942.
<a href="https://en.wikipedia.org/wiki/United_States_Army_Institute_of_Heraldry" class="extiw" title="en:United States Army Institute of Heraldry">en:United States Army Institute of Heraldry</a>
1942-10-26
<cite style="font-style:normal"> (1943). "<a rel="nofollow" class="external text" href="http://archive.nationalgeographic.com/dynamic/National%20Geographic%20Society/National%20Geographic/Landing.aspx">Aircraft Insignia, Spirit of Youth</a>". <i>The National Geographic Magazine</i> <b>Vol. LXXXIII</b> (No. 6): 718-722. National Geographic Society. Retrieved on <span class="mw-formatted-date" title="2017-09-01">September 1, 2017</span>.</cite> (subscription required for web access) modified with Microsoft Paint