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accidentally discovered that An Thoi was also home to a prison camp for
captured Vietcong. "I was on the back of a flat pickup truck with all these


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bags of mail going to the U.S.," he said. "A C-130 troop transport flew in
and landed on an airstrip. I was probably about fifty yards or less away.
It turned and the tail end almost lined up to the back of the truck. The
back door opened up and out ran about thirty to fifty screaming
Vietcong. They came charging toward me. The Marines fired over their
head. They didn't realize that there was an innocent bystander there. I
still have flashbacks and post-traumatic stress over it."
Later, the Oxford's sister ship, the USS Jamestown, was also ordered
to the area. The Jimmy-T, as it was known, was assigned to the South
China Sea around Saigon and the Delta region. "There was always a
rivalry between our sister ship . . . and us," said Richard E. Kerr, Jr. "In
the aft ops area, we had a huge wooden hand carved into the classic 'the
bird' position. I do not know the story behind it, but I think it had some
funny inscription like, 'From one sister to another.' "
Down below, in the Oxford's forward NSA spaces, intercept operators
listened with highly sensitive KG-14 multichannel receivers. To translate
the information, the Sigint unit had linguists qualified in Lao/Thai,
several Chinese dialects, Russian, and Vietnamese. Among the intercept
operators on board was at least one qualified in Tagalog, the language of
the Philippines. "We did as much processing as we could," recalled De
Chene. "Fort Meade wanted both recordings and transcripts and our
breakdowns of it. Pretty much full scope of as much as we could cover . .
. For about two weeks we had one NSA guy on board. He kept to himself.
I don't think anybody knew why he was there." In the aft area, Elint
operators collected the signals of hundreds of radar systems on huge
reels of Mylar tape attached to 32-track Ampex recorders.
Among the most important assignments during the Oxford's years in
Southeast Asia was the Seven Nations Manila Summit Conference, which
took place in the Philippine capital on October 23”27, 1966. Anchored
in Manila harbor, right across from the Stanley Point Naval Air Station,
the ship was able to eavesdrop on the negotiations. Thus, American
negotiators got a leg up by discovering the strategies and arguing points
of the other players. At one point, intercept operators on the ship
"uncovered a plot," said De Chene, "to assassinate [U.S. President
Lyndon B.] Johnson, [Philippine President Ferdinand E.] Marcos, and I
think Nguyen Cao Ky." The plotters were members of the Communist-
inspired Huk movement. As a result of the intercept operators' warning,
every member of the ship received a letter of commendation.
The Sigint personnel and the rest of the ship's crew, referred to as
general service personnel, were in effect segregated. "The general service
personnel had no idea what we did, or how we did it," said De Chene. "All
they knew was at the commencement of the workday, we would file
behind those security doors, both fore and aft of the ship, and we would
reappear at noon for chow. For the most part, they stayed away from us


265
and in greater or lesser degrees, we, them. It was as if there were two
different Oxfords, and I guess there really were." Ray Bronco agreed:
"They [the Sigint personnel] were in a world of their own."
In July 1966, NSA decided to have the Jamestown temporarily relieve
the Oxford and send Oxford to conduct signals intelligence operations
along the coast of mainland China. At the time the secretive and violent
Cultural Revolution was going on. "After about two weeks of cruising up
and down China's coastline," said De Chene, "our results were fairly
meager at best. From all appearances, the Chinese knew when and
where we were going to be and for the most part, their communications
transmissions were held to a bare minimum, or none at all."
But while the eavesdropping proved quite boring, the South China
Sea gave them more excitement than they desired. Typhoon Ora was
moving rapidly toward the Oxford, "We were taking severe rolls," De
Chene recalled, "and the storm was growing stronger. The following day
all hell broke loose. We lost a boiler and we were now dead in the water,
almost at the center of the typhoon. We were drifting, and the wind was
pushing us right into the coastal waters of Red China."
An emergency message went out for help and a fleet tug was
dispatched for rescue. But more than a day went by without any sign of
help. "All hands were now briefed on our full situation," said De Chene,
"and advised that an abandon ship order might be given, and the CTs
[communications technicians] were put on standby to destroy all
equipment and documents. The captain also considered putting our
utility boat and his gig in the water to possibly either start towing the
ship or at least slow her drift. At this point we were approximately twenty
miles from the beach, or eight miles from Chinese coastal waters. Finally,
after drifting inland for two more miles, the tug made its appearance and
shot us her lines. She then towed us back to Taiwan and out of harm's
way of both capture and the storm."


The war in Vietnam was layered, like a wedding cake, and it was
fought from the ground up. After the ambush death of James Davis as he
prowled through the jungle near Saigon attempting to pinpoint enemy
signals, NSA began experimenting with direction finding from the air.
"Since radio wave propagation in Southeast Asia required that DF
equipment be very close to the transmitter," said an NSA report, "the
obvious answer was to go airborne."
While some airborne Sigint and DF missions required enormous
planning, others were seat-of-the-pants, such as the chopper missions.
Flying near treetop level just south of the DMZ were intercept operators
in UH-1H "Huey" helicopters. With antennas duct-taped to the chopper's
skids, the operators searched for North Vietnamese Army


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communications signals. Inside, a Vietnamese linguist listened for
infiltrators through earphones attached to a captured North Vietnamese
Army backpack radio. "They used to make them out of their beat-up
green .50-caliber ammo cans," said one intercept operator. "It had a few
dials on it with Chinese characters."
The pilots on board had KY-58 secure voice systems to quickly and
secretly pass the time-sensitive information back to base. "Most of the
time we were flying we picked up their communications," said the
intercept operator, "so you would get a lot of information. But it would be
very time-critical. The units were always on the move, so if you didn't get
the information back really quick it would be of little use. Tactical
intelligence is very of-the-moment, versus strategic, which is long-range,
overall planning." Once NVA units were located, airborne or ground
troops would be sent in after them.
Unlike the other services, the Army had paid little attention to
airborne Sigint since the end of World War II. Throughout the 1950s,
Army intercept operators flew missions in Navy aircraft. The codename of
one of their operations in the early 1960s, also aboard a Navy Sky
Warrior, seemed to sum up the problem: Farm Team. It was at that point
that the Army decided to invest both manpower and funds in developing
its own professional team of aerial eavesdroppers. By March 1962 the
Army Security Agency had its first airborne DF platform, the RU-6A De
Haviland Beaver, a single-engine aircraft that flew low and slow and had
room for very few operators. Within days, intercept operators in the unit
were calling it TWA: Teeny Weeny Airlines.
Far from the sleek, high-flying U-2 or the lightning-fast SR-71, the
early Sigint planes in Vietnam were almost comical. "The operators hung
a long wire out the back of the aircraft for a crude direction-finding
antenna," said one veteran. "Crews flew in hot, humid conditions in very
loud aircraft. Missions were often four hours long, but could be longer
depending on the operational tempo of the forces in contact." The planes
may have looked funny, but they provided vital information. "It has been
said," the veteran reported, "that air missions produced as much as one-
third of the intelligence known to ground forces."
Later, a more advanced aircraft joined the fleet of Beavers. This was
the RU-8D Seminole, a stubby black twin-engine with room for five
passengers. Tall thin blade antennas protruded vertically from the tips of
the wings, giving the diminutive spy plane a somewhat menacing look.
Richard McCarthy was one of those who volunteered for the 3rd Radio
Research Unit's 224th Aviation Battalion. Flying out of Tan Son Nhut Air
Base, McCarthy would often be assigned to the Saigon River Delta area,
an inhospitable, mosquito-ridden wedge of swamp that stretched from
Saigon to the sea. Because it was also the main shipping channel to



267
Saigon, it became a haven for pirates and small groups of Vietcong
guerrilla fighters. "Whoever controlled the shipping channel controlled
Saigon," said McCarthy.
Because the Delta area was so compact, the single-engine Beaver was
preferred. Wedged behind the copilot, the plane's skin to his back and
two Collins 51S1 receivers in front of him, McCarthy would be listening
for enemy communications through one of his helmet's earphones, and
to the Beaver's pilot and copilot through the other. Navigation consisted
of looking out the window for landmarks, and wads of masking tape were
applied to the doors to prevent the plotting sheets from being sucked out.
Two hours into one mission over the Delta, McCarthy's earphones
began buzzing”the familiar sound of a guerrilla tuning his transmitter
for a call. "He was good and he was loud," said McCarthy. "It was show
time." In an attempt to locate the guerrilla's transmitter, the pilot would
twist and turn the plane back and forth to obtain different bearings on
the target. Once the enemy forces were plotted, the crew would call in an
air strike.
As NSA began sending more and more airborne eavesdroppers to
Vietnam, the sky became an aviary of strange-looking metal birds
hunting for signals to bring back to their nests. Two miles above the
choppers and puddle jumpers was the EC-121M "Big Look," a Lockheed
Super Constellation with monstrous radomes on its top and bottom. To
some, the plane resembled a humpbacked and pregnant dinosaur.
Because it was heavy and the cabin wasn't pressurized, it was limited to
about 10,000 or 12,000 feet. Lined up along the windowless bulkheads,
the intercept operators attempted to squeeze every electron of intelligence
out of the ether during each twelve-hour mission, providing warnings to
U.S. attack aircraft.
Warnings were critical. In the late spring of 1972, General John Vogt
dispatched an eyes-only message to the Air Force Chief of Staff, General
John Ryan, frankly stating that the 7th Air Force was losing the air war.
The problem, Vogt said, was the increased proficiency of North
Vietnamese pilots and their ability to make single, high-speed passes
while firing Atoll missiles. Facing them were inexperienced U.S. pilots
rotating into the combat zone every year.
NSA came up with Teaball, a system in which detailed warnings based
on Sigint were quickly sent to the pilots. Many at the agency opposed the
idea of broadcasting in the clear such secret information, but the concept
was eventually approved.
Teaball was set up in a van at NSA's large listening post at Nakhon
Phanom in northern Thailand. There, intercept operators would
broadcast to the fighters, via a relay aircraft, the latest Sigint on surface-
to-air missile sites and MiG fighters in their area. When Sigint revealed


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that a specific U.S. aircraft was being targeted for destruction, the pilot,
nicknamed "Queen for the Day," would be instantly notified. "Naturally,
that particular flight element began to sweat profusely," said Doyle
Larson, a retired Air Force major general involved in Teaball, "but all
other strike force elements relaxed a bit and let Teaball take care of
them." A veteran pilot and Sigint officer with over seventy combat
missions in Vietnam, Larson said that "Teaball was an instant success."
The kill ratio for American fighters attacking North Vietnamese MiGs
"increased by a factor of three."
Above the choppers, the Beavers, the Seminoles, and Big Look were
the RC-135 flying listening posts”Boeing 707s filled with intercept
operators and super-sophisticated eavesdropping equipment. From
Kadena, Okinawa, the planes would fly daily twelve-hour missions,
codenamed Burning Candy and Combat Apple, to the Gulf of Tonkin.
Eventually, as the war heated up, more and more missions were
flown, until an RC-135 was constantly on station in the northern Tonkin
Gulf twenty-four hours a day. It was an incredibly demanding schedule.
Each mission lasted just over nineteen hours, including twelve over the
Gulf. Two missions were flown every day, with a third aircraft on
standby, ready for immediate launch if the primary aircraft had a
problem. All the while, the five RC-135s in the Far East were also needed
to cover the numerous Sino-Soviet targets. The missions took their toll
not only on the crews but on the aircraft, the corrosive salt spray and
high humidity ulcerating the planes' aluminum skin.
The North Vietnamese air force knew full well the purpose of the
aircraft and would occasionally try to shoot it down. "MiG-21s would
streak out over the Gulf at supersonic speeds and make a pass at the
RC-135," said veteran Sigint officer Bruce Bailey. "Both fuel and fear
limited them to only one pass. They would fire everything they had and
run for the safety of their AAA [anti-aircraft artillery] and SAM [surface-
to-air missile] umbrella back home." Although the RC-135 was a prize
target, none was ever lost to a MiG.
Wherever they flew, the RC-135s were electronic suction pumps,
especially the RC-135C, nicknamed the "Chipmunk" because of its large
cheeklike antennas. The reconnaissance systems on board were
programmed to automatically filter the ether like kitchen strainers,
"covering the electronic spectrum from DC [direct current] to light," said
Bailey. "It had such a broad coverage and processed so many signals at
such an incredible rate it became known as the ˜vacuum cleaner.' It
intercepted all electronic data wherever it flew, recording the information
in both digital and analog format."
At the same time, the Chipmunk's numerous onboard direction
finders were able to automatically establish the location of each emitter



269
for hundreds of miles. Sophisticated computers located signals that in
any way varied from the norm, and highlighted them. Other key voice
and data frequencies were preprogrammed into the computer and
instantly recorded when detected. "The volume of data collected by that
system was sufficient to require an entire unit and elaborate equipment
to process it," said Bailey. "That large and impressive operation became
known as 'Finder.' The amount of intelligence coming out of Finder was
staggering.
"With its vacuum cleaner capability and very little specific tasking in
the war zone," said Bailey, "the Chipmunk spent only a couple of hours
in the combat area on those missions. It went in, sucked up all the
signals, let the two high-tech operators look around a little, then
resumed its global tasks."
Still another RC-135 variation, sent to Vietnam late in the war, was
the RC-135U "Combat Sent," which had distinctive rabbit-ear aerials. It
has been described as "the most elaborate and capable special mission
aircraft ever . . . with technical capabilities that seemed like science
fiction."
Still higher in the thinning layers of atmosphere above Vietnam were
the unmanned drones that could reach altitudes in excess of 12½ miles.
"They were designed to intercept communications of all sorts: radars,
data links, and so forth," said Bruce Bailey. "The intercepted data was
then transmitted to other aircraft, ground sites, or satellites." Based at
Bien Hoa Air Base near Saigon, the diminutive drones contained so many
systems as to give rise to a joke: the Ravens claimed that they also
contained "a tiny replica of a field-grade officer to take the blame for
anything that went awry."
The program proved very successful. On February 13, 1966, one of
the Ryan drones "made the supreme sacrifice," said Bailey, but in the
seconds before it became a fireball it intercepted and transmitted to an
RB-47 critical information on the SA-2 missile, including the fusing and

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