The General Dynamics-Grumman EF-111A Raven is an electronic-warfare aircraft designed to replace the B-66 Destroyer in the United States Air Force. Its crews and maintainers often called it the "Spark-Vark", a play on the F-111's "Aardvark" nickname.
The USAF contracted with Grumman in 1974 to convert some existing General Dynamics F-111As into electronic warfare/electronic countermeasures (ECM) aircraft. The USAF had considered the Navy / Marine Corps Grumman EA-6B Prowler, but desired a penetrating aircraft with supersonic speed.
The EF-111 entered service in 1983 and served until its retirement in 1998. Afterwards, the Air Force began depending on Navy and Marine Corps EA-6Bs for electronic warfare support.