The Japan-based units of USAFSS were formed in the early 1950’s and were assigned to the 1st Radio Squadron, Mobile (RSM), at Johnson Air Base (AB), Japan, operating out of Yokota AB, Japan, both just outside of Tokyo. The unit conducted reconnaissance missions against the former Soviet Union and North Korea mostly in modified bomber aircraft known as RB-29’s and RB-50’s.
This is also when the unit's bat symbol originated (see the crew patch at upper right of this page), a term used by front-enders (that would be the pilots and navigators) to describe the dark, cave-like existence of the airmen in the back of the aircraft.
In early 1963 to 1 July 1963, the flying unit at Yokota became the RSM, and the unit at Fuchu AS was redesignated Detachment 1, now the subordinate unit of the RSM at Yokota. On 1 July 1963, the 6988th RSM, Yokota AB, became the 6988th Security Squadron (SS) when all USAFSS RSM’s became security squadrons.
Note: The following interesting historical snippet was culled from an article ("The short but interesting life of a plane called rivet top") published 22 September 2007 by William Cahill in Air Power History, a journal of the Air Force Historical Foundation:
"USAF airborne SIGINT missions supporting the
Vietnam War were about as old as the war itself. The 6091st
Reconnaissance Squadron introduced SIGINT to Vietnam in July 1964 when
it deployed two C-130B-II SIGINT aircraft to Thailand to fly COMINT
missions off the coast of North Vietnam. Originally operating under the
mission name Queen Bee, the C-130B-II aircraft would orbit over the Gulf
of Tonkin to gather information on VPAF [North Vietnamese People's Air
Force - ed.] air defenses as USAF strike
aircraft bombed North Vietnam under Operation Rolling Thunder. The
tenuous relationship between the operations community and the
intelligence community flared as the Second Air Division, the USAF
organization controlling the air war at the time, fought with the SIGINT
community over tasking of the SIGINT aircraft and the releasability of
their intelligence information. The original method to "sanitize" and
relay threat warnings derived from SIGINT was deemed cumbersome and a
contributing factor in the loss of two F-105 aircraft on April 4, 1965.
The fallout of this incident was overwhelming and within one month the
USAF approved the Queen Bee crews to provide enemy fighter (or "MiG")
threat warning direct to the strike aircraft over UHF radio on the
"Guard" channel; by August the warnings were expanded to include
information on active VPAF SA-2 [SAM] batteries. In mid-September 1964 two
additional C-130B-II aircraft arrived in theater, allowing the 6091st to
fly a total of two missions per day under the new mission name of Silver
In September, 1967, the first USAFSS-manned “Combat Apple” RC-135 mission staged out of Kadena. As the 135’s flew more missions, the need for the C-130’s in Asia declined, and the RC-130’s were transferred to Europe in 1971 to replace the aging RC-130 “A” models.
OL-1 (Operating Location 1) of the 6988th SS was activated at Osan in 1969 after North Korean seizure of the USS Pueblo in Jan ’68. As the Viet Nam war was escalating, negotiations were under way in the States to add RC-135’s to the inventory of reconnaissance aircraft used by USAFSS. In mid-1967, the 6990th Security Squadron was established at Kadena AB, Okinawa (at the time, still a U.S. Territory).
In early 1972, a DoD Program Budget decision completely realigned the cryptologic structure in Japan, forcing the inactivation of the 6988th SS at Yokota and two other units.
But the 6988th was to live on—however temporarily, and at the opposite side of the globe. In 1980, the then Electronic Security Command (the immediate successor to USAFSS) redesignated the 6954th ESS (Electronic Security Squadron) at RAF Mildenhall, U.K., as the 6988th Electronic Security Squadron in honor of the unit that operated out of Yokota for nearly 20 years.
On 1 October 1993, the 6988th ESS was redesignated the 488th Intelligence Squadron (its present day designation) as part of the restructuring of the newly formed Air Intelligence Agency (AIA, the third successor to USAFSS [see successor organizations]) as a field operating agency which occurred on the same date.