United States Air Force Security Service

The USAF identified the potential for using airborne platforms to intercept line-of-sight VHF communications during the Korean War. In April, 1952, a test mission of the first Airborne Reconnaissance Program (ARP) on a converted B-29 took place.[3] The Airborne Communications Reconnaissance Program (ACRP) was initiated in 1955, engaging in flights collecting Signals Intelligence (SIGINT) along the coasts of China, North Korea, and the Soviet Far East.[7]

On July 29, 1953, a 343d Strategic Reconnaissance Squadron RB-50G-2 was shot down off the USSR coast near Vladivostok, and resulted in the first loss of USAFSS airborne operators in a hostile act.[1]

In 1964, the USAFSS began using the C-47 Airborne Direction Finding platform, providing intelligence to U.S. and friendly commanders throughout Southeast Asia.[9]

From 1964 to 1971, Kadena AB was the home-base for long-range surveillance flights over China, DPRK, and North Vietnam by unmanned aerial vehicles (UAVs) or ‘drones’ produced by Ryan Aeronautical Company.[7]

USAFSS support to national customers expanded in the late 1950s and early 1960s. USAFSS ground units opened in out of the way places around the globe, including Diyarbakir, Karamürsel, Samsun and Trabzon Air Force Detachments in Turkey, Iraklion Air Station, Crete, Zweibrucken and Wiesbaden Air Bases in Germany, Royal Air Force Kirknewton in Scotland, and Peshawar, Pakistan.[9] In the 1970s, major installations included Misawa AB, Japan, San Vito Air Station, Italy and RAF Chicksands, England.

Locations like Elmendorf AFB and Clark AB were equipped with direction finding shops from which "fixes" on targets could be obtained by requesting a line of bearing from other direction finding shops in other locations around the world. This would give a triangulation fix on a target and that target could then be plotted on a board and the coordinates then forwarded to take proper action on the targets. All this was accomplished by using the AN/FLR-9 antenna. The antenna array covered 35 acres (140,000 m²) of ground and was composed of A, B and C band elements that covered the high frequency (HF) range of signals that targets of interest transmitted on.

In the late 1950s, the USAFSS developed a new mobile operations concept. The first mobile unit deployment in 1956 was in response to an unstable Middle East.[1] In the 1960s, more ERUs were added to facilitate quick response of intelligence collection capabilities in a crisis.[10]

In Japan, a mobile contingency team, maintained by the 6918th Security Squadron, deployed to conduct site surveys and establish intercept sites. Some of the deployments required civilian clothing to mask the nature of their activities.[7]

In July, 1974, a 114-man ERU was sent to San Vito Air Station, when hostilities broke out between Cyprus and Crete.[3]

From its inception, USAFSS also maintained a cadre of TRANSEC (Transmission Security), later known as COMSEC (Communications Security) personnel. Their mission consisted of monitoring and analyzing US military radio, teletype, and telephone communications to identify practices and individual communications that could compromise or endanger sensitive or classified operations. The missions initially employed 292X1 Morse operators and 202X0 analysts for analysis and reporting.

TRANSEC/COMSEC teams operated in both tactical and strategic environments, utilizing both fixed locations and deployed (TDY) teams. In 1970, deployed missions became a major portion of the mission, with teams utilizing S-141 shelters specially configured for each mission. They also used a variety of "manpack" positions configured for radio and telephone surveillance and shipped or handcarried into the field. The S-141 shelters were later replaced by a command-designed truck-based system, the AN-MSR-1. Due to design shortcomings and a low ceiling, the system was better known to operators as the "MISERY".

TRANSEC/COMSEC units and teams provided a variety of message reports, parallel to SIGINT reporting, directly to their tasking authorities (not the NSA) and to tactical/field commanders who could take actions based on the reports. Units also provided hardcopy summary reports to their tasking authorities. Many USAFSS personnel were dedicated to this mission throughout their Air Force careers, while others moved between TRANSEC/COMSEC and the more traditional SIGINT operations. The TRANSEC/COMSEC mission was occasionally used as a cover story for SIGINT operations. Likewise, deployed TRANSEC/COMSEC teams occasionally used USAFSS SIGINT units as cover for Trusted Agent/covert missions.