Douglas EB-66 ELINT ECMDouglas EB 66 Destroyer ECM airplane model. EB 66 aircraft formed a necessary complement to an F 105 strike force in the target area. Effective Electronic Countermeasures (ECM) and Electronic Intelligence (ELINT) were mandatory for force survival in the highly concentrated defense environment of North Vietnam. The North Vietnamese defenses consisted of small arms, automatic weapons (i. e. . 30 and . 50 cal. machine guns), antiaircraft artillery (AAA