A <a href="https://en.wikipedia.org/wiki/Pratt_%26_Whitney_R-2000_Twin_Wasp" class="extiw" title="en:Pratt &amp; Whitney R-2000 Twin Wasp">Pratt &amp; Whitney R-2000 Twin Wasp</a> radial engine, mounted in the No. 3 position on the starboard wing of a Douglas DC-4 undergoing maintenance.
<a href="https://en.wikipedia.org/wiki/User:YSSYguy" class="extiw" title="wikipedia:User:YSSYguy">YSSYguy</a> at <a href="https://en.wikipedia.org/wiki/" class="extiw" title="wikipedia:">English Wikipedia</a>
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Digital image taken by YSSYguy on 29 March 2011 and uploaded for use in the  article. Image edited using Picasa software. <a href="https://en.wikipedia.org/wiki/User:YSSYguy" class="extiw" title="en:User:YSSYguy">YSSYguy</a> (<a href="https://en.wikipedia.org/wiki/User_talk:YSSYguy" class="extiw" title="en:User talk:YSSYguy">talk</a>) 11:17, 29 March 2011 (UTC)