The single U.S. Navy Lockheed XR4O-1 (BuNo 1441) at the NACA Langley Research Center in 1938. In 1938 the U.S. Navy ordered a staff transport version of the Lockheed Model 14-H2 <i>Super Electra</i>. It was delivered to the USN on 15 October 1938 and remained in the inventory until 1944. The aircraft spent most, if not all, of its service life based at Naval Air Station Anacostia, Washington D.C. (USA). The Lockheed Hudson was later developed from this plane.
NASA
1938
<a rel="nofollow" class="external text" href="http://lisar.larc.nasa.gov/UTILS/info.cgi?id=EL-1997-00257">NASA</a> photo <a rel="nofollow" class="external text" href="http://lisar.larc.nasa.gov/IMAGES/LARGE/EL-1997-00257.jpeg">EL-1997-00257</a>