Twentieth Air Force emblem.  Approved  15 October 1991.  This emblem replaced the emblem approved on 26 May 1944 by placing it on an Air Force shield.  It was replaced on 18 May 1994 by an emblem that rendered the background of the shield the same color as the globe and made minor alterations in the shade of the wings and type used for the number.
<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>
1991-10-15
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