A ski-equipped U.S. Navy Lockheed P2V-2 <i>Neptune</i>, in 1949.
U.S. Navy
<a rel="nofollow" class="external text" href="http://www.navy.mil/ah_online/department_arch.html">U.S. Navy All Hands magazine</a> <a rel="nofollow" class="external text" href="http://www.navy.mil/ah_online/archpdf/ah195001.pdf">January 1950</a>, p. 35.