TINKER HISTORY: O-series engines

Single Vultee USAF L-5 shown in flight. This aircraft is powered by an O-series engine. (Photo courtesy of the Tinker History Office)

Single Vultee USAF L-5 shown in flight. This aircraft is powered by an O-series engine. (Photo courtesy of the Tinker History Office)

A Lycoming O-360 engine mounted on a Piper Cherokee shows the important characteristics of O-series engines: horizontally opposed cylinders on either side of the crank-shaft which turns the propeller (lower front).  Tinker maintained various engines of this type throughout the years as they were common for early Liasion, trainer and even drone aircraft. (U.S. Air Force photo/Greg L. Davis)

A Lycoming O-360 engine mounted on a Piper Cherokee shows the important characteristics of O-series engines: horizontally opposed cylinders on either side of the crank-shaft which turns the propeller (lower front). Tinker maintained various engines of this type throughout the years as they were common for early Liasion, trainer and even drone aircraft. (U.S. Air Force photo/Greg L. Davis)

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