Radioplane OQ-17

The Radioplane OQ-17 was a target drone built by the Radioplane Company for the U.S. Army Air Forces and, under the names TD4D and KDR Quail, for the U.S. Navy. Its production was halted early in favor of the OQ-19 because its engine proved unreliable.

As World War II wound down, the Army Air Forces wanted a new target drone that could outperform the earlier OQ-2 series and better mimic the capabilities of modern fighters. Reginald Denny designed the RP-18 in response, an all-metal aircraft with a high-mounted wing and a conventional tail.

It was powered by a Righter O-45 four-cylinder horizontally opposed engine, launched from a catapult, and controlled by standard radio. If it survived a training engagement, it could be recovered using an onboard parachute. The manufacturer claimed the OQ-17 could match any maneuver a typical fighter could perform.

The RP-18 was first evaluated in March 1945. After trials, the Army Air Forces ordered it into production in February 1946 as the OQ-17.

The Navy also ordered it, having tested it as the XTD4D-1; the production version was initially designated TD4D-1, then redesignated KDR-1 Quail. Only 430 OQ-17 and KDR drones were built, as persistent problems with the O-45 engine could not be solved. The Radioplane OQ-19 was ordered as its replacement.

Variants included the RP-18 prototype; the XOQ-17 test version for the Army; the production OQ-17; the Navy’s XTD4D-1 test version; the TD4D-1 production version; the KDR-1 (the definitive Navy production version); and the KDR-2, which had structural improvements.