<hi style=afpcap>The Douglas O-2 series were producted in a variety of forms, with designations O-25, O-29 and O-38 also being applied to modified versions. The O-29s were converted to basic trainers with the designation BT-2 and BT-2A being applied. Production versions of the BT-2B (illustrated) and BT-2C were ordered in 1931, with some being modified with anti-drag rings as instrument trainers as BT-2BI and BT-2CI. </hi>