Air America's Black Helicopter
The secret aircraft that helped the CIA tap phones in North Vietnam.
- By James R. Chiles
- Air & Space magazine, March 2008
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The Quiet One had a forward-looking infrared (FLIR) camera on its belly that helped the pilots navigate at night.
Shep Johnson
Photos from: "Air America's Black Helicopter"
BLACK HELICOPTERS ARE A FAVORITE
FANTASY when conspiracy theorists and movie directors conjure a
government gone bad, but in fact, the last vehicle a secret
organization would choose for a stealthy mission is a helicopter. A
helicopter is a one-man band, its turbine exhaust blaring a piercing
whine, the fuselage skin's vibration rumbling like a drum, the tail
rotor rasping like a buzzsaw.
In the last dark nights of the Vietnam
War, however, a secret government organization did use a helicopter
for a single, sneaky mission. But it was no ordinary aircraft. The
helicopter, a limited-edition model from the Aircraft Division of
Hughes Tool Company, was modified to be stealthy. It was called the
Quiet One—also known as the Hughes 500P, the "P" standing
for Penetrator.
Just how quiet was the Quiet One? "It
was absolutely amazing just how quiet those copters were,"
recalls Don Stephens, who managed the Quiet One's secret base in Laos
for the CIA. "I'd stand on the [landing pad] and try to figure
out the first time I could hear it and which direction it was coming
from. I couldn't place it until it was one or two hundred yards
away." Says Rod Taylor, who served as project engineer for
Hughes, "There is no helicopter today that is as quiet."
The Quiet One grew out of the Hughes
500 helicopter, known to aviators in Vietnam as the OH-6A "Loach,"
after LOH, an abbreviation for "light observation helicopter."
The new version started with a small research-and-development
contract from the Advanced Research Projects Agency (now the Defense
Advanced Research Projects Agency) in 1968. The idea of using hushed
helicopters in Southeast Asia came from the CIA's Special Operations
Division Air Branch, which wanted them to quietly drop off and pick
up agents in enemy territory. The CIA bought and then handed over two
of the top-secret helicopters to a firm—by all appearances,
civilian—called Air America. Formed in 1959 from assets of previous
front companies, Air America was throughout its life beholden to the
CIA, the Department of State, and the Pentagon.
The Quiet One's single, secret mission,
conducted on December 5 and 6, 1972, fell outside Air America's
normal operations. The company's public face—what spies might call
its "legend"—was that of a plucky charter airline
delivering food and supplies to civilians in Laos, and flying
occasional combat evacuation missions in Laos and South Vietnam.
While it did substantially more than that, and at considerable peril
(217 of its employees died in Laos), Air America crews did not make
it a practice to fly deep into North Vietnam.
The mission was intended to fill an
information gap that had been galling Henry Kissinger, secretary of
state under President Richard Nixon. Negotiations to end the 11-year
war had begun in March 1972 but stalled in part because South
Vietnamese leaders feared that North Vietnam would invade not long
after U.S. troops left. A five-month Air Force and Navy bombing
campaign called Operation Linebacker had brought the North Vietnamese
to the negotiating table in Paris that October, but even that
campaign could not force a deal. Kissinger wanted the CIA to find out
whether the North Vietnamese were following the peace terms or just
using them as a smokescreen for attack plans.
From its intelligence work a year
earlier, the CIA knew about a weak point in the North Vietnamese wall
of security: a telephone line used by the country's military
commanders, located near the industrial city of Vinh. A patrolled
bicycle path ran alongside the string of telephone poles, but at one
spot, about 15 miles southwest of Vinh and just east of the Cau
River, the phone line went straight up a bluff, over a ridge, and
down the other side. The terrain was too steep for bikes, so the path
followed the river, which flowed around the bluff, rejoining the
telephone poles on the bluff's far side (see hand-drawn map, p. 67).
This would be the best place to drop off commandos to place a
wiretap.
Because the Vinh tap would be sending
its intercepts out of North Vietnam, across Laos, and into Thailand,
it would need a solar-powered relay station that could catch and
transmit the signal, broadcasting from high ground. The station would
be within earshot of enemy patrols, so both the tap and relay would
have to be dropped in by helicopter—a very quiet one.
Disturbing the peace
The Hughes Tool Aircraft Division had
started working on such a helicopter in 1968; that year an affluent
suburb of Los Angeles had bought two piston-powered Hughes 269
helicopters for police patrols. Citizens soon called to complain
about the noise of the low-flying patrols, and the city told
Hughes to either make them quieter or
take them back. An emerging market for police patrols was at stake.
Engineers at Hughes identified one of the worst of the noisemakers:
the tail rotor. By doubling the number of blades to four, Hughes was
able to cut the speed of the rotor in half, which reduced the
helicopter's noise.
Coincidentally, the Advanced Research
Projects Agency was hunting for contractors who could cut noise from
military helicopters of all sizes. After hearing about Hughes' work
on the police helicopters, ARPA offered the company $200,000 in 1968
to work similar magic on a Hughes OH-6A light helicopter. Hughes Tool
made a short movie about the modifications, which included a new set
of gears to slow the tail rotor, and showed it to ARPA. "ARPA
came back and offered a blank check to do a Phase Two of the program
with no holds barred," recalls Taylor, the project engineer.
"Each and every noise source in the helicopter was to be
addressed in an attempt to reduce the signature to an absolute
minimum." ARPA gave the project the code name Mainstreet. Even
before work was fully under way, the CIA ordered two (later
registered as N351X and N352X) for use in the field. Test flights
began at Culver City, California, in 1971, followed by a brisk
training program for the U.S. instructor-pilots who would later train
mission pilots.
Flights of the Quiet One included
low-level work at the secret Air Force base Area 51 in Nevada and
touchdowns on peaks in California to familiarize pilots with
close-quarters maneuvering and landing in darkness. Pilots needed at
least eight hours to get comfortable with steering by sole reference
to the comparatively narrow view of the forward-looking infrared
(FLIR) camera, which was mounted just above the skids. Says Allen
Cates, an Air America pilot who flew one in 1973: "When you saw
a person, it was like looking at a photo negative. Or you'd see just
the hood of a car, glowing from heat off the engine block…. And
when you were landing, a blade of grass looked as big as a tree."
The slapping noise that some
helicopters produce, which can be heard two miles away or more, is
caused by "blade vortex interaction," in which the tip of
each whirling rotor blade makes tiny tornadoes that are then struck
by oncoming blades. The Quiet One's modifications included an extra
main rotor blade, changes to the tips on the main blades, and engine
adjustments that allowed the pilot to slow the main rotor speed,
making the blades quieter (see "How To Hush a Helicopter,"
p. 68). The helicopter also had extra fuel tanks in the rear
passenger compartment, an alcohol-water injection system to boost the
Allison engine's power output for short periods, an engine exhaust
muffler, lead-vinyl pads to deaden skin noise, and even a baffle to
block noise slipping out the air intake.
The extensive alterations did not blank
out all noise, Taylor says. Rather, they damped the kinds of noise
that people associate with a helicopter. "Noise is very
subjective," he says. "You can reduce the overall noise
signature and an observer will still say, 'I can hear it as well as
before.' It's related to the human ability to discriminate different
sounds. You don't hear the lawnmower next door, but a model airplane
is easily heard. It has a higher frequency and seems irritating."
Hughes shipped the two Quiet Ones to
Taiwan in October 1971. Under the CIA's original plans, the Vinh
wiretap mission would be flown by pilots from the Taiwanese air
force's 34th Squadron. This would offer the United States some
deniability, however flimsy, if any of the helicopters were captured.
The pilots' U.S. instructors included two veteran helicopter pilots
with experience flying low-level missions in Vietnam: Lloyd George
Anthony Lamothe Jr. and Daniel H. Smith. The two had joined Air
America six months earlier for that purpose.
The decoys arrive
Meanwhile, Air America's fleet in
Thailand accepted delivery of two more Hughes 500 models—standard
ones—and used them for air taxi operations. The job of these
plain-vanilla Loaches was to distract attention from the Quiet Ones
before they even landed in Laos. Loaches were common in Vietnam but
not in Laos, so Air America needed to start using them in full view
of North Vietnamese sympathizers. That way, if an enemy observer
later saw the modified Loaches flitting past on a moonlit night, he
might not consider the event worthy of comment.
Initial flight training on the Quiet
Ones, conducted in Taiwan, was complete by June 1972. The two
helicopters and their gear traveled on a C-130 transport to an
isolated airstrip in Thailand called LS-05. Mechanics pulled them
out, swung the rotor blades for flight, and filled the tanks, and the
two helicopters flew by night to an even more obscure base, a secret
one in southwest Laos known to insiders as PS-44. PS stood for "Pakse
Site," a reference to the garrison town of Pakse, 18 miles to
the southeast. PS-44 had been built to house Laotian commandos and
the aircraft that flew them around. Its dirt strip and three tin-roof
buildings sat on the edge of a plateau, surrounded on three sides by
steep ground that was unusual for its expanses of bright beach-like
sand, eroded from nearby cliffs of white sandstone.
It appeared to be far away from
everything, but it was not far from the enemy. By late 1972, units of
the North Vietnamese army were ensconced 20 miles to the north. To
offer some peace of mind, the CIA had Air America keep a turbine
transport helicopter, the Sikorsky S-58T "Twin Pack," handy
for evacuations. More reassuring, the terrain was so steep and
overgrown that the enemy could have stormed it from only one
direction: the west. The base also relied on a perimeter of six guard
posts staffed by Laotian soldiers, and reinforcements could have been
called in from a base lying southwest, along the Mekong River.
No pictures allowed
Cameras were discouraged at PS-44, and
photographing the Quiet One was strictly forbidden. Crews already
knew the risk of telling tales in the bars and brothels of Southeast
Asia, but even inside the base, the code of silence persisted. "You
just
didn't come up and introduce yourself
at PS-44," says Dick Casterlin, an Air America pilot who came to
the base often. "Nobody talked about their personal background
or where they were from." Men who worked closely for months knew
each other only by first names or nicknames. The CIA itself had its
own nickname at PS-44: The men called it simply "the Customer."
Casterlin flew an S-58T helicopter
during some of the wiretap attempts, accompanying the Quiet One in
order to rescue the wiretap teams if that became necessary. Casterlin
had a security clearance for special missions, but even he wasn't
told where the CIA had hidden the Quiet One.
According to base manager Stephens, the
Quiet One was kept out of sight about 600 yards northwest of PS-44's
main building, reachable down an unmarked, narrow forest trail.
Because of the distance, the forests, and the quieting gear, the
helicopter couldn't be heard from the porch of the base's main
building unless it was flying overhead. Even then, at night, it
sounded like a far-off airplane. The helicopter had its own hangar so
Soviet spyplanes and satellites could not get a look at the peculiar
profile produced by the extra main rotor blade, a tail rotor with
blades in an odd scissored configuration, and big muffler on the rear
fuselage.
Between June and September, Lamothe and
Smith tried to train the Taiwanese crews to fly the mission, but
after months of poor performance by the trainees—including a
botched night landing that demolished one of the two Quiet Ones—and
bickering over who would be the chief pilot, the CIA managers got fed
up and sent the whole contingent home. Lamothe and Smith prepared to
fly the mission themselves.
At the same time, the agency placed the
project under new management. James Glerum arrived in Pakse to direct
operations. Glerum had been the CIA's assistant base chief at Udorn
Royal Thai Air Force Base when the Quiet Ones landed in Laos. The new
assignment demonstrated how urgently the state department wanted the
wiretapped information, according to Air America chief helicopter
pilot Wayne Knight. Glerum, he says, was a CIA "super-grade,"
outranking many careerists at headquarters.
Soon after his arrival, Glerum quizzed
Smith and Lamothe on their cover story. When he realized they had
none, he provided them with false identities and a story to go with
them in case of capture.
More help came from Air America, which
was offering up its best aircraft (the term used was "gold-plated")
and its most experienced men to support the mission. One was Thomas
"Shep" Johnson, a rangy Idahoan with a background in
smoke-jumping. Johnson had started with Air America in its first
year, 1959, rigging bundles with parachutes and pushing them out of
aircraft. A year before, he had been one of only three men to survive
a North Vietnamese attack at another Laotian air base. Johnson's main
responsibility was to train a squad of eight Laotian commandos for
the Vinh wiretap mission. For years, the commandos had been fighting
communist forces and had reported on enemy traffic along the Ho Chi
Minh Trail in eastern Laos. A group of 100, they lived in a separate
part of PS-44 and manned the perimeter.
The CIA had hoped to get the wiretap in
place before monsoon season, but a series of mishaps and equipment
malfunctions, compounded by the monsoons starting early, delayed the
mission. "We had a string of unbelievably bad weather,"
says Glerum. "Normally, November to January is the rainy season.
It had started right as I got there [in October]." Twice Lamothe
and Smith took off from PS-44 to fly the wiretap mission, refueling
in eastern Thailand and heading into enemy territory, only to turn
back after running into clouds in the passes or fog at the wiretap
site. "The preparation for the mission was a very hectic time,"
says Stephens, "but it also seemed like it dragged on forever."
TECHNICAL DIFFICULTIES
Hughes technicians toiled over the
troublesome infrared camera; problems with it had forced cancellation
of an October 21 attempt. "The FLIR [forward-looking infrared]
required a lot of work," recalls Glerum. Other gadgetry included
SU-50 night-vision goggles (their first use in Laos), which worked
only when the moon was a quarter to a half full. The helicopter also
had a long-range navigation system (LORAN-C).
Any mishap during the night flight into
North Vietnam, particularly while the crew maneuvered among trees and
telephone poles, would doom the mission and probably its
participants. By day Lamothe and Smith studied photos and maps
marking the stealthiest route to the target. By night they practiced
by using LORAN to navigate from the hangar to a nearby training
ground they called the Hole. The topography of the Hole was an
"astonishingly accurate duplicate" of the actual wiretap
site, according to Glerum. Flying into and out of it was "no
problem in the daytime, [but] it could be a bugger at night,"
recalls Casterlin. Smith and Lamothe dropped the commandos near a
simulated telephone pole (a tree stripped of branches and equipped
with a cross arm) and flew to a pre-selected tree, where they laid
out the radio rig called the spider relay.
The spider relay was to be deployed as
the helicopter hovered over a tree. With its solar panels,
electronics boxes, and antennas sprung open to a width of almost 10
feet, the relay perched atop the branches with a fishnet-like
webbing. It was nearly impossible to see from the ground. The relay
could be folded into a compact package that fit between the
helicopter skids, but there was so little ground clearance left after
it was attached, the pilots could land only on a hard, flat surface.
When each night's practice was
complete, Lamothe and Smith flew back through the darkness to the
concrete landing pad, which was shaped like an old-fashioned keyhole.
The approach to landing was memorable because the Quiet One used no
landing lights; it relied on an infrared floodlight on the nose. The
light cast an eerie, ruddy glow.
Some of the biggest threats to mission
success came not from North Vietnamese army spies but from plain bad
luck. One flight opportunity was lost when a scorpion bit a wiretap
team commando, setting off an allergic reaction. On one of the
training flights at the Hole, after Lamothe and Smith deployed the
spider relay used for practice, it slid off the branches and crashed
to the ground, with pieces scattering. Training for the mission could
not proceed without the relay, and joyful speculation spread among
the ranks: It would be a month or more until a new spider could come
from the States, so the men could go on leave.
But no: Stephens flew to the spot by
helicopter, slid down a rope, and helped technician Bob Lanning bag
up the pieces. Back at camp, Lanning laid them out on a floor and
said he could get the relay working if he had some new parts. "Jim
Glerum sent a cable," says Stephens, "and in three days we
had the parts by courier. Bob worked two and a half days, almost
nonstop, and put it back together. So we only lost a few days."
With the moon entering the favorable
phase, the rescue crews moved to a forward staging base in eastern
Thailand while Lamothe, Smith, and the Quiet One remained at PS-44.
An attempt was scheduled for the night of December 5, amid rising
doubts among Air America veterans as to whether the scheme would ever
work.
That night, the Quiet One flew to a
refueling base at the Thai-Laotian border, where it met a de
Havilland DHC-6 Twin Otter with the Laotian commandos. Two commandos
with guns and the wiretap equipment climbed aboard the Quiet One, and
the rest stayed on the Otter with parachutes and more guns in case
they were needed for a rescue. Accompanied by an armed Twin Pack
flown by Casterlin and Julian "Scratch" Kanach, the Quiet
One set course for the northeast. The Twin Pack broke away at the
North Vietnamese border and took up a slow orbit over Laos, out of
radar range but on call if needed. Despite the Twin Pack's readiness
to play the rescue role, security was as tight as ever. "I did
the LORAN navigation, but I didn't have the coordinates of the
wiretap location," Casterlin says. "I assumed they'd tell
me if I needed to know, or maybe Scratch knew."
Leaving the Ho Chi Minh Trail, and
without being targeted by the anti-aircraft defenses along it,
Lamothe and Smith climbed to cross the Annamese mountains, then
dropped to follow the nap of the earth, following streambeds when
possible. When the pilots identified the wiretap spot, they hovered,
and the two Laotian commandos jumped a few feet to the ground.
Lamothe and Smith then flew west across
the Cau River to a 1,000-foot-high mountain to set the spider relay.
Finding the ideal tree for the relay had taken months of intense
photo-
reconnaissance work. The tree had to be
tall, on high ground with a clear view of the western horizon, and
flat at the crown. An Otter orbited over a receiver relay, which was
already in place atop another mountain halfway into Laos. Inside the
Otter, technicians were watching an oscilloscope measure a test
signal from the spider relay.
Meanwhile, the Laotian commandos at the
wiretap site found that the poles were concrete rather than wood, so
they couldn't use their pole-climbing boots to get up them or a
stapler to attach the antenna. The men shinnied up instead. After
splicing into the phone wires, they put the tap in place; it was
concealed in a glass insulator of the same color used on the
French-built line. The commandos began taping up the short-range
antenna and installing narrow solar panels atop the pole's cross-arm.
This would power the tap's transmitter.
When Lamothe and Smith heard from the
Otter that the Thai oscilloscope was getting a clear signal from the
spider relay's transmitter, they threw a switch that released the
last cables connecting the spider relay to the helicopter and flew
the Quiet One to a streambed to wait for the commandos to finish
attaching the solar panels. At the scheduled time, Smith restarted
the helicopter's turbine; he picked up the commandos at the wiretap
site and the team returned to Laos without incident. Those listening
to progress reports at PS-44, Udorn, and the Lima 40A refueling site
were pleasantly startled to hear that the crew was on its way back
and the tap was in place without a firefight, recalls Wayne Knight.
"What makes the Vinh tap so
special is that they pulled it off," Knight says. "It had
to be right the first time."
DISAPPEARING ACT
Lamothe and Smith left the Quiet One at
PS-44 and flew to the CIA's regional office at Udorn by conventional
aircraft. Much celebration at ensued there—perhaps too much. During
the subsequent R&R, someone at the Wolverine Night Club in town
bit off part of Smith's ear. If a reprimand for attracting attention
was ever entered in Smith's secret personnel file, it didn't matter:
The CIA had no plans to send the Quiet One up again, and within a
week all the Americans connected with the mission and their equipment
were on their way out of Laos.
Recollections differ on how long the
Vinh tap worked—perhaps one to three months—and why it went
silent. But allegedly it yielded enough inside information from the
North Vietnamese high command to help nudge all parties to sign a
peace pact in late January 1973. Exactly what Kissinger eavesdropped
on remains classified.
"I was not aware of any specifics
Kissinger and company were looking for," Glerum says. "Since
the land line [at Vinh] was understood to hold the command channel,
virtually anything would have been welcome."
The one flyable Quiet One relocated to
California. Air America pilots Allen Cates and Robert Mehaffey
trained on it at Edwards Air Force Base, achieving proficiency in
early 1973. Then, before any special-mission training began, and with
no explanation, Cates and Mehaffey were sent back to their old
piloting jobs at Air America. Mechanics pulled most of the special
features out of the Quiet One, and its trail of insurance and
registration papers ends in 1973, after it was transferred to Pacific
Corporation of Washington, D.C., a holding company used as a screen
for CIA-backed companies and assets.
"The agency got rid of it because
they thought they had no more use for it," says Glerum. At least
one of the ex-Quiet Ones surfaced years later at the Army's Night
Vision & Electronic Sensors Directorate in Fort Belvoir,
Virginia.
But according to the participants, no
more were built. It's puzzling why the CIA did not keep a stable of
Quiet Ones, at least while the technology remained under wraps. And
it remained a secret for more than two decades, until Ken Conboy and
James Morrison told the story in their 1995 book Shadow War.
But there were valid reasons for
dropping the Quiet One from the spymasters' catalog.
"In the long run, the 500P was not
the best for setting wiretaps," says Casterlin. "It was not
good for high-altitude work." It was a light helicopter and had
to be loaded with gear that cut into its payload capability and
operating altitude. The Twin Pack was much louder but also simpler to
run and more powerful, so Air America used it for later wiretap
missions in North Vietnam. At least one tap, placed on the night of
March 12-13, 1973, was successful.
Some of the Quiet One's innovations did
show up on later helicopters, including the Hughes AH-64 Apache,
which has a scissor-style tail rotor. And Hughes engineers' interest
in modifying the tips of the main rotor blades to cut the slapping
noise caused by blade vortices has been taken up by other experts.
Aerospace engineer Gordon Leishman and his team at the University of
Maryland, for example, are developing a blade with curved tubes at
the tip to divert the air, thereby countering vortex formation. But,
thanks to its many unusual modifications, the 500P still holds the
title that Hughes gave it in April 1971: "the world's quietest
helicopter."
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Shep Johnson
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Shep Johnson
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Department of Defense
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A Laotian commando practices for the secret operation.
Shep Johnson |
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Shep Johnson
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