Mixed Signals May Have Misguided
U.S. Weapons
Source: The Washington Post
January 22, 1989
When U.S. warplanes. were ordered to, strike Libya in
1986, they ran into an electronic blizzard that Pentagon officials now
suspect might have caused one of the fighters to crash and others to
miss their targets.
The disruption came not from the Libyans, but from
high-powered U.S. military transmitters that filled the night sky with
electronic signals designed not only to enable the fighters to
communicate but to jam Libya’s antiaircraft defenses, hunt targets,
and guide weapons.
The Pentagon is so alarmed by the problem it has
launched a $35 million effort to identify the interference and keep it
from happening again, according to Air Force Col. Charles Quisenberry,
who is leading the probe. The study is expected to take three years.
During the Libyan strike, U.S. weapons "were interfering
with each other and they [U.S. commanders] came back out of that and
they said: ’Look, we’ve got some problems here, and we want to know if
we’re doing it to ourselves, or if the bad guys did. it to us,’"
Quisenberry said in an interview. "The end result was we found out we
did it to ourselves."
President Ronald Reagan ordered the April 1986 strike
after U.S. intelligence linked Libya to the terrorist bombing of a
West Berlin nightclub’ in which a U.S. serviceman was killed.
During the attack, 18 Air Force and 15 Navy planes
attempted. to strike five targets after U.S. planes and ships
saturated the air with powerful electronic transmissions.
Quisenberry said radio-wave interference might have led
to the downing of an F111 jet fighter, whose two crew members were the
only U.S. fatalities in the attack.
Numerous U.S. weapons, some of which were electronically
guided, went astray during the attack, damaging three foreign
embassies and diplomatic residences, including those of France and
Japan. And several of the 32 surviving planes including five F111s
aborted their mission without firing a shot because of unspecified
problems. Recent Pentagon studies have shown that some combinations
of U.S. weapons transmitting radio waves at certain frequencies can
bring down U.S. warplanes, Quisenberry said.
Some radio waves common above the battlefield "will
actually affect the electrons within the aircraft’s flight controls as
well as its fuel controls," he said, either putting a plane into an
uncommanded turn or dive or turning off its fuel supply.
Quisenberry recently finished a classified seven-month
investigation of the problem which led top pentagon officials to order
the more detailed three-year study.
"There are major, major problems out there that need to
be addressed." Quisenberry said. "The proliferation of equipment that
operates in the electromagnetic spectrum keeps growing. It’s finally
gotten to the point where we’ve got to do something about it."
Quisenberry and his staff of 65, working from the
Tactical Air Warfare Center at Eglin Air Force Base in the Florida
panhandle, will study the Pentagon’s primary war plans. For the first
time, they will calculate how radio emissions from the weapons of one
service might disrupt the sophisticated electronic gear of the other
services.
Before conducting tests on weapons in the field,
Quisenberry’s study is using computers to detect problems.
A preliminary study of one war plan revealed "thousands
of (radio wave) conflicts" among the weapons slated to be used in the
event of a war in that region, Quisenberry said.
"Many people have told us that a lot of people will not
be happy with what we find out because we’ll actually uncover
problems," he said. "If there’s a problem with the B1, that might not
be politically acceptable-people may have some heartburn with that."
He said his goal is to inform U.S. and allied commanders
of potential problems and recommend tactics to avoid them-either by
assigning new frequencies to certain weapon transmitters or assuring
that conflicting weapons are kept far enough apart to prevent
interference.
Tests using weapons "where we can turn the equipment on
full blast" are to begin. this summer, Quisenberry said.
In the past, he said, the Pentagon too often ignored its
safeguards designed to protect weapons from electromagnetic
interference (EMI).
"In many cases, a program manager will get an exemption
for. getting a weapon delivered without having EMI looked at
completely;" Quisenberry said.
Such waivers have been "a kind of run-of-the-mill thing,
to be honest with you," he said. "In many cases, you have politics
involved in getting a product developed, or a program manager has a
schedule to meet. The most important thing is that there was not a
hammer-someone saying you could not build a certain weapon until its
EMI problems were fixed."
Last year, the Army acknowledged that flight near large
transmitters could put its UH60 Black Hawk helicopter into uncommanded
turns. The service has begun a $175 million program to shield the
Black Hawk’s flight control computers from such radiation. Since 1982
as many as five UH60 crashes that killed 22. servicemen may have been
due to electromagnetic interference.
"The Black Hawk was shielded at a very low level - it
was known ahead of time that its shielding was inadequate,"
Quisenberry said. "There was a lot of corporate knowledge that knew it
wasn’t going to hack it."
by Mark Thompson