The AQM-60 Kingfisher, originally designated XQ-5, was a target drone version of the USAF's X-7 ramjet test aircraft built by the Lockheed Corporation.

[1] The X-7's development began in 1946 after a request from the USAF for a Mach 3 unmanned aerial vehicle for test purposes.

[2] The Kingfisher was capable of evading the vast majority of weapons systems it was used to test, despite the systems being designed to destroy hypersonic missiles in flight.

This created much embarrassment at the USAF and considerable political fallout.

An endurance variant of the same engine was produced for use in the Lockheed D-21, which was launched from the back of a Lockheed SR-71 Blackbird mothership or from under the wing of a Boeing B-52 Stratofortress nuclear bomber.