Laffing Eagle

Laffing Eagle was an airborne radio direction finding system used by the US Army. The system was mounted on modified U-21 Ute utility aircraft, designated RU-21D.

The Laffing Eagle was a radically different system from previous ARDF systems mounted in similar sized aircraft that the Army had used, such as Seven Roses, Winebottle, Cefish Person, and Checkmate. The Laffing Eagle system had 2 operators, one being the intercept operator as found in previous systems, as well as second direction finding operator. This second person removed the direction finding load from the cockpit. Now the direction finding was done using a small cathode ray tube scope and electronic magic to take the direction finding shots, which could be taken without having to point the airplane directly into a signal null. Direction finding operators simply spun their dials creating their own null, pushed a button, and out came a printed slip of paper with the shot direction and aircraft position derived from the aircraft's own very accurate inertial navigation system.

A total of 17 Laffing Eagle systems were built, with the first deployed to Vietnam in 1968. The Laffing Eagle systems were removed from service with the introduction of the Left Foot, Cefirm Leader, and Guardrail systems.