The prototype was later fitted with an enclosure over the pilot's cockpit and was fitted with geared V-1570-29 engines, being redesignated XO-27A.
In 1930, Fokker-America was absorbed by the General Aviation Corporation, which was a subsidiary of General Motors, the large automobile manufacturing concern. On April 11, 1931, the company received a contract for six service test YO-27s (31-587/592). A month later, six service test YB-8s were ordered (31-598/603).
The first YO-27 was flown on September 10, 1932, and was issued to the 12th Observation Group based at Brooks Field, Texas. The YO-27 had longer engine nacelles and was equipped with windows in the nose. There was a single Browning machine gun in a flexible position in the nose and another Browning machine gun in a flexible position in the rear cockpit.
The XB-8 (29-328) was delivered to Wright Field in February of 1931. The XB-8 did not have as good a performance as the competing Douglas XB-7, and only one example of the XB-8 was built.
The six YB-8s that had been ordered by the Army were redesignated Y1O-27 before they were manufactured and were delivered as observation planes. In any case, the advances in bomber design that took place in the early 1930s had become so rapid that both the XB-7 and XB-8 were deemed obsolete and no production was ordered for either design.
In 1933, the General Motors Corporation underwent a major reorganization and joined its General Aviation Corporation subsidiary into a large conglomerate along with other GM-owned aircraft companies such as Berliner-Joyce and the Curtiss-Caproni Corporation.
This conglomerate was also known as the General Aviation Corporation. The complex of General Motors aircraft plants was later organized as the Eastern Aircraft Division and was to manufacture thousands of aircraft under license during the Second World War.