Friday, August 11, 2006
Explosives expose aviation weak
spot
By Alan Levin and Dan Vergano
USA TODAY
Thursday's terror
plot didn't succeed in blowing up planes, but it struck at the core of a
fundamental weakness in aviation security around the globe: the inability to
spot explosives made from seemingly harmless ingredients.
That's the bad
news.
The good news, according to former FBI explosives expert J.
Christopher Ronay: Bringing down an airliner with a bomb is not guaranteed. A
terrorist's success would depend on where the bomb was planted. A bomb near a
wing or a fuel line would be devastating; a bomb elsewhere might do less
damage.
Rep. John Mica, R-Fla., chairman of the House Aviation
Subcommittee, says the type of bombs that an alleged London terror group
intended to use to crash planes into the Atlantic probably would have slipped
through airport detection devices armed even with the latest
technology.
"This is a new approach to destroying our aviation system
using what I call clean bombs or explosive components to take down multiple
aircraft," Mica says. "We face a very serious challenge in that regard. If they
get to the checkpoint, our chances of detecting them are limited."
U.S.
and British authorities have refused to identify the specific components that
the suspects arrested Thursday planned to carry aboard planes. A senior U.S.
intelligence official with knowledge of the investigation said the explosive
they had chosen is called hexamethylene triperoxide diamine (HMDT) and is based
on hydrogen peroxide.
Common liquids found in the home, including hair
bleach and food preservatives, could be processed, then combined on board a
plane after takeoff, to make HMDT.
The typical methods used to detect
explosives at airports — swabs that test the exterior of luggage and explosive
detection machines — would largely be useless against such
ingredients.
Dogs are often the last line of defense against bombs, but
they can only detect chemicals they have been trained to recognize. They may not
be able to detect chemical components of a bomb.
"An almost limitless
list" of compounds can be used to create explosives, says Ronay, now at the
Institute of Makers of Explosives, a Washington, D.C.-based safety group.
"Terrorists know this stuff — it's in their training."
Intentional
bombings have occurred aboard civilian aircraft since at least 1955, he said.
The first involved an Illinois man who placed a bomb made of dynamite in a
relative's suitcase to collect insurance money.
While all checked bags
bound for a jet's cargo hold are screened for explosives, the vast majority of
carry-on bags are not. Carry-ons pass through X-ray machines, which may be able
to detect the wires in a bomb's detonator, but can't show whether a bag contains
explosives.
Passengers also must pass through metal detectors before
boarding a plane and their shoes are X-rayed. Virtually no one is checked for
explosives.
"This is the greatest vulnerability that we have," says Rep.
Peter Defazio, D-Ore., the ranking Democrat on the Aviation
Subcommittee.
It's happened before
Defazio has been calling for
greater explosive detection at checkpoints for years because of several
successful attempts to take bombs aboard planes. In one infamous scheme, hatched
in the Philippines in 1994, Ramzi Ahmed Yousef, a Pakistani terrorist linked to
al Queda, planned to blow up airliners en route to the USA with nitroglycerin
bombs that were to be mixed on the planes by terrorist
operatives.
According to investigative records, he successfully tested
his bomb on Dec. 11, 1994. He brought the chemicals aboard a Philippine Airlines
flight in nondescript containers, including a contact lens solution
bottle.
He mixed them together in the plane's toilet to create the bomb,
attached it beneath a seat and got off the jet at a layover.
The
explosion tore out a 2 square foot portion of the cabin floor and ripped in half
the body of 24-year-old Haruki Ikegami, a Japanese businessman occupying the
seat. He was an industrial sewing machine maker returning from a trip to Cebu,
Philippines. Flight attendants placed a blanket where he was seated.
The
bomb blew a hole in the cabin floor, revealing the cargo hold underneath. The
fuselage of the plane stayed intact, and the plane landed in
Okinawa.
Although the bomb did not take down the jet, Yousef was
convinced that he could make a larger explosive that would.
Investigators
who eventually captured him and charged him with the 1993 World Trade Center
bombing and the airline plot believed that he could, too. He was convicted of
conspiring to crash the planes.
Though the plot is well known, Defazio
says that not enough has been done to prevent another such attempt.
At
one hearing in recent years, he recalled asking a new appointee to a top
homeland security post whether he knew who Yousef was. The appointee, whom
Defazio declined to identify, did not.
"I said, 'You better find out,' "
the congressman recalls.
"We have done nothing at the checkpoints to
detect the kind of bomb that (Yousef) designed and is available to be copied on
the Internet. That is just unconscionable."
Location of a bomb, along
with its size, is a key factor, Ronay says. If the blast destroys structural
elements or jet fuel lines, the plane will crash. However, blowing out aluminum
sheeting without damaging the aircraft's overall core may still allow the plane
to land in some circumstances.
The December, 1988 explosion of a Pan
American Airline plane over Lockerbie, Scotland, involved only about a pound of
high explosives inside a suitcase that ended up in the luggage bay in a location
near the plane's command center where it did the most damage, destroying the
jet's structure.
"It just happened to be the worst place," Ronay
said.
Assembly not that easy
Although common household cleaners
and other liquids can be used to create explosives, it's not as easy as it
sounds, says Neal Langerman, a chemist with the American Chemical Society, the
world's largest chemistry organization, and formerly head of the group's health
and safety division.
"It's something of a misstatement to say that
because liquid explosive components are commercially available that anyone can
make them," says Langerman. "One component you might be able to get at Home
Depot, but the other one would require a chemist to purify and jump through the
whole process."
Even then, the process would be inherently risky for
anyone trying it, he says.
Sulfuric acid used in drain cleaners, hydrogen
peroxide and nail polish remover are some of the ingredients found in bombers'
recipes. But at least one of the ingredients in a bomb typically requires
chemical refining to purify it — a difficult and dangerous process, Langerman
says.
Hydrogen peroxide, an ingredient in many homemade bombs and the one
the would-be British bombers planned to use, is found in many medicine cabinets.
"But it's way too diluted" to use, as is, for explosives, says Ronald Atkins,
who chaired a 1998 National Research Council effort on explosives.
Can
problem be solved?
The problems with protecting against explosives
extends far beyond the ability to find a peroxide-based bomb. Most carry-on bags
and people are not even checked for those explosives that can be
detected.
Technology already exists to use low-level X-rays to screen
passengers for hidden weapons or dynamite or plastic explosives that might be
missed by metal detectors. Critics initially complained that it would violate
people's privacy because it also displays a person's body. Newer versions block
out the body, but still the device has not been put into
airports.
Defazio and others have accused TSA of moving too slowly to
purchase "puffer" machines that blow air over passengers to detect whether they
have come in contact with explosives such as dynamite.
After
experimenting with the machines for several years, TSA will purchase 147 of the
machines this year.
"If they are really serious about security, why after
five years are there only a few puffer machines?" says Duane Woerth, president
of the Air Line Pilots Association. "They're not putting their money where there
mouth is, quite frankly."
There seems to be a lack of political will in
the USA and Europe to purchase the latest explosive screening technology, says
Chris Yates, an aviation security analyst with Jane's Airport
Review.
"TSA continues to deploy the latest technology to enhance our
explosive detection capabilities at the checkpoint," TSA spokeswoman Amy von
Walter said. "In addition, we've provided advanced bomb training to our
screening workforce to address the threat of explosives."
Current airport
tests are "not designed to pick up most liquid explosives," says chemist Jimmie
Oxley of the University of Rhode Island. "That's what I tell my FBI (Academy)
students. You have to think where the terrorists will go next after you (knock)
down one approach" to creating a bomb.
And while the list of possible
explosives is vast, the ones that are easy to use and widely available are less
imposing, Oxley says. "Those are the ones that law enforcement will concentrate
on," she says.
Mica says he asked government security experts to test
whether the component parts of a bomb — which could include simple ingredients
such as concentrated hydrogen peroxide and camping stove fuel — could be
detected.
In May, a German chemistry team outlined the difficulties
authorities faced in developing a detection test for two common peroxide-based
explosives, TATP and HMTD, used in the past by terrorists. The article in
Analytical and Bioanalytical Chemistry journal suggested that authorities have
tests for samples of these explosives, but effective air monitoring for only
one, TATP, is now possible.
HMTD, the explosive involved in the British
bomb plot, gives off fewer vapors.
Oxley, the University of Rhode Island
scientist, predicts that, despite the difficulties, airport bomb scanners will
add liquid explosive ingredients to their capabilities within perhaps a
year.
Langerman is less sure. "I think the world we knew of easy carry-on
luggage is gone," he says.
Attached
Photo:
EXPLOSIVES POSE
DIFFERENT THREATS
Graphic: Terrorists
target flights
Chicago Police officer Art Munoz and his dog, Troy, check baggage
Thursday at Midway Airport. Aviation security's weakness is not being able to
spot explosives from seemingly harmless ingredients.
