How many years was the EC-121 Warning Star in service?

The EC-121 Warning Star was the radar surveillance version of the Constellation family. It was used by both the US Navy and the US Air Force as an airborne early warning and control aircraft. It entered service in 1954 and was retired in 1978; a single modified aircraft remained with the Navy until 1982. Its original mission was to complement the DEW (Distant Early Warning) Line, the chain of ground-based radars deployed in the north to give early warning of a possible bomber attack.

What made the EC-121 recognizable were its two large radomes: one vertical above the fuselage and one horizontal below it. That silhouette, added to the Super Constellation airframe, made it one of the most striking aircraft of its time. The Museum of Aviation preserves an example with serial number 141297, whose unit cost was put at $2,031,000.

Over the years, the EC-121s also took on signals intelligence gathering. That role placed one of them at the center of a crisis: on 15 April 1969, a Navy EC-121M with the call sign Deep Sea 129 was shot down by two North Korean MiG-21s over the Sea of Japan, killing all 31 aboard. In Vietnam, the EC-121R variant, known as Batcat, numbered as many as 30 aircraft in the 553rd Reconnaissance Wing, based at Korat, Thailand, between 1967 and 1970. That unit was deactivated on 15 December 1970, after the QU-22B reached full operational status on 1 October of that year and reduced the need for the EC-121.