FS2002 Douglas O-46A. The O-46A got its start as the XO-31 prototype in 1930. There were 90 O-46A aircraft delivered between May 1936 to April 1937. It served the USAAC until 1940. Most were transferred to the National Guard then transferred to training units. This model carries the icon of the 91st Observation Squadron. These files are public domain. By Ted Simko.