EF-111 RavenEF 111 Raven Sparkvark airplane model. The development of the EF 111A Raven, also known as "Spark Varks," began in January 1975 when the Air Force contracted with Grumman Aerospace to modify two F 111As for electronic warfare purposes. With its high speed, long range, substantial payload, and reasonable cost, the F 111 was the perfect platform to protect allied tactical forces against enemy radar defenses. The EF 111A fulfilled this role by using a