TINKER AIR FORCE BASE, Okla. -- O-series engines powered many small aircraft used by the U.S. military in a wide variety of missions. O-series is the common name for reciprocating engines featuring horizontally-opposed pistons connected to a central crankshaft.
Some of the earliest and sustaining work performed at Tinker was in support of maintenance, repair and overhaul of O-series engines which powered Army Air Corps and later U.S. Air Force aircraft and some U.S. Navy drones, too. Commercial engine manufacturers such as Continental, Franklin and Lycoming produced engines in four and six-cylinder configurations as original equipment for aircraft when purchased.
The types maintained here at Tinker included Continental O-170, 65 horsepower on Aeronca L-3, Interstate L-8, Luscombe UC-90, Piper L-4 and Taylorcraft L-2. Lycoming O-290, 160 horsepower on Piper L-21 and Franklin O-300, 150 horsepower on Culver PQ-14 target drones for the Air Force and Navy. Lycoming O-435, 240 horsepower engines powered the Stinson L-5.
According to official Tinker history documents, the Oklahoma City Air Depot kept the fleet of small liaison planes used for many years by the Army Air Corps and later the U.S. Air Force in-service. The substantial engine work done on aircraft using O-series engines and later radial engines at Tinker set the foundation for the many companies throughout Oklahoma who continue to specialize in aircraft engine repair and overhaul.
Manufacturer: various
Engine type: piston
Nickname: O-series
Horse-power: between 65-240
In-service dates: 1943-1950
Number produced: 3,970
Tinker connection: maintenance, repair and overhaul