The Navion was originally designed at the end of World War II by North American Aviation as the NA Ryan L-17B-143 (but produced under the NA-145 designation). It was designed for the civilian market but also attracted the interest of the United States Army Air Forces. The Army Air Force ordered 83 of the NA-154 version, designated the L-17A, to be used as a liaison aircraft, personnel and cargo carrier, and trainer for the university-based Reserve Officers Training Corps flight training program, 35 of which were later converted to L-17C standard by the Schweizer Aircraft Company by fitting them with L-17B model features such as an auxiliary fuel tank.