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cover Southeast Asia, DSUs were stationed on
them, as in the case of the USS Maddox.
Operationally, these units were controlled by the
Navy's command structure, beginning with the
Chief of Naval Operations. This control was delegated
down the chain of command, usually finally
residing with the on-site commander to which
the DSU was assigned. The National Security
Agency and the Naval Security Group provided
technical support. In most cases, these units
maintained a separate communications link, or a
channel on the Fleet Broadcast for the transmittal
and reception of messages on the Criticomm and
Opscomm circuits.
(8//81) The primary miSSIOn of the naval
DSUs was SIGINT support to the local commander.
This meant that all DSU resources,
COMINT and ELINT intercept, tactical reporting
support, and communications were steered in
that direction. As the war widened and the tempo
of naval operations increased, the DSUs were
placed on other ships performing specialized missions.
One unique type was the Search and
Rescue/Anti-Air Warfare Destroyers (SAR/
AAW). These vessels were tasked with rescue of
downed American pilots and also fleet air
defense. This latter mission was expanded to
include placement of SIGINT teams on board the
PIRAZ vessels that housed the controllers for
intercept of North Vietnamese MiGs during
Rolling Thunder. Later, some national tasking,
especially on the Desoto missions, was laid on by
NSA.
(SI/S1) As the number of personnel available
for DSU duty increased, more and more navy
ships added them to their complements. These
teams would be placed on board with their equipment
in specially configured spaces known as
supplementary radio facilities (SUPRADS) which
supported SIGINT operations. These facilities
included from three to five intercept spaces and a
special communication position. SUPRADS were
complements to the Desoto huts.
(V) Exterior ofSVPRAD spaces on the
VSS Providence CLG-6)
(U) The Air Force Security Service
(S//SI) This period also saw the final arrival
and organization of the AFSS in Southeast Asia.
Within the region, the Security Service presence
was not very large. In fact, the majority of
Security Service personnel who served in
Indochina were actually stationed outside the
region, but served as collectors and analysts on
ACRPfli hts
Depending on the capabilities of
the airframe, these flights would redeploy from
their home bases to those in Vietnarnj
and rotate back on a regular basis.
"----------'
(S//S1) On the ground the AFS$ manned two
sites: Danang, RVN, belonging to Detachment 2
of the 6925th Security Group (USA-32), and
IBy the/beginning of 1967,
L- r_..,Iintercept responsibilities
were transferred to Udorn. The Air Force
mission there (renotated/USA-29 in November
I
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