40th Helicopter Squadron emblem
<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>
2003-07-10
Air Force Historical Research Agency <a rel="nofollow" class="external free" href="http://www.afhra.af.mil/factsheets/factsheet.asp?id=17504">http://www.afhra.af.mil/factsheets/factsheet.asp?id=17504</a>