The Lockheed aircraft RC-121D, which was also called the Lockheed aircraft, was a United States Air Force and United States Navy airborne early warning system that supplemented the Distant Early Warning Line. It came with two huge radomes, with one being horizontal located below the fuselage and the other, a vertical one, situatedpositioned on top of the aircraft. The aircraft was used for gathering intelligence (SIGINT). Introduced in 1984, the US Air Force and the US Navy used the Lockheed...