A U.S. Navy Naval Aircraft Factory PN patrol plane in flight off Pearl Harbor, Hawaii, in 1925.
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/ah196304.pdf">April 1963</a>, p. 10.