Douglas YOA-5
The Douglas YOA-5 was an Amphibious aircraft designed for the United States Army Air Corps. Although a prototype was built, it did not enter production. Design and development. In November 1932, the U.S. Army ordered the development of an amphibious reconnaissance aircraft/bomber, intended to act as navigation leaders and rescue aircraft for formations of conventional bombers. The resultant aircraft, which was ordered under the bomber designation YB-11, was designed in parallel with the similar but larger Douglas XP3D patrol flying boat for the United States Navy. It was a high-winged monoplane with two Wright R-1820 Cyclone  radial engines mounted in individual nacelles above the wing, resembling an enlarged version of the Douglas Dolphin. Prior to completion, it was redesignated firstly as an observation aircraft YO-44 and then as the YOA-5 'observation amphibian model 5'. It first flew during January 1935, and was delivered to the army during February that year. The concept for which it was designed proved impracticable, and no further production ensued, but the YOA-5 was used to set two world distance records for amphibians, being finally scrapped in December 1943.