6990th Security Group

• Origins: The 6990th Security Group was established in 1967 at Kadena Air Base, Okinawa, Japan, as a United States Air Force signals intelligence (SIGINT) unit. • Mission: Its primary mission was to conduct airborne and ground-based signals intelligence operations, especially during the Vietnam War and throughout the Cold War era. • Crewed RC-135 Aircraft: The group provided linguists, analysts, and cryptologists for RC-135 reconnaissance aircraft, notably the RC-135M 'Rivet Card' and RC-135U 'Combat Apple' missions. • Vietnam War Contributions: The 6990th played a crucial role in monitoring North Vietnamese communications, providing real-time intelligence to U.S. forces and supporting air operations such as Operation Rolling Thunder. • “The Front End” and “The Back End”: Members often referred to themselves as “backenders” because they operated in the back of reconnaissance aircraft, analyzing intercepted communications in real time. • Tragic Loss: On June 13, 1969, a 6990th crew aboard an EC-47 aircraft was shot down over Laos (call sign “Baron 52”), resulting in the loss of the entire crew. Their sacrifice is memorialized among U.S. Air Force intelligence personnel. • Cold War Operations: The 6990th monitored Soviet, Chinese, and North Korean military communications, contributing to U.S. situational awareness in the Pacific region. • Awards: The group received multiple Air Force Outstanding Unit Awards for its exceptional performance and contributions to national security. • Transition: In 1993, the 6990th was inactivated and its legacy continued when its mission and personnel were absorbed into the 390th Intelligence Squadron. • Legacy: Veterans of the 6990th have formed alumni groups and reunions, preserving the heritage and camaraderie of this unique signals intelligence unit.