Liquid Explosives in Foiled U.K. Plot Expose Gaps in Security
11 August 2006
By Charles Goldsmith and Subrata N. Chakravarty
When U.K. police thwarted a plot to blow up airliners bound for the U.S., they exposed a weakness in aviation security and created a new focus in the war on terror: liquid explosives.
The plotters may have planned to bring liquids onto aircraft and mix them in-flight to create explosive devices, U.S. Homeland Security Secretary Michael Chertoff said yesterday at a press conference in Washington. Passengers on U.S. airlines were immediately barred from taking any liquids or gooey substances, including toothpaste and shampoo, on board.
The ban underscores how the threat to airplane security has moved beyond metal and guns to hidden chemical explosives, including ignitable liquids and vapors. The U.K. government said the plot could have been deadlier than the Sept. 11 attacks on New York and Washington, after which worldwide air traffic dropped by as much as a third.
``We've had detection machines in place in many airports, but they're not always effective because they don't pick up very innocuous-looking substances that are homemade,'' says Andy Oppenheimer, editor of Jane's Nuclear, Biological and Chemical Defence, a publication based in Coulsdon, England. ``There isn't a foolproof method.''
Nitroglycerin, which he says is one of the candidates for substances involved in the U.K. plot, can be made to look like ``an ordinary drink,'' Oppenheimer says.
U.K. authorities arrested 24 people after learning that the suspected terrorists might do a test run in the next couple of days and carry out their plan soon thereafter, said a U.S. intelligence official who declined to be identified.
The U.S. and U.K. raised their terror alerts to the highest level as London's Heathrow, Europe's busiest airport, canceled incoming flights. BAA Plc, Heathrow's operator, said yesterday that the airport would be working normally today, with most airlines resuming operations.
``Explosive-detection research is among the highest of our priorities, including liquids,'' Chertoff's deputy, Michael Jackson, said yesterday on a conference call with reporters. Researchers are studying several new devices that might identify liquid explosives, he said.
``There is nothing currently that's suitable for mass deployment, but there are some promising technologies we've been looking at,'' Jackson said.
The plotters were figuring out which airlines to target when they were arrested, with their focus on carriers that have ``direct, non-stop flights between the U.S. and the U.K.,'' Jackson said.
Larry Johnson, a former Central Intelligence Agency analyst, says the U.S. Transportation Security Administration should be doing more to detect liquid explosives.
``This technology has been out there for 60 years,'' Johnson says. Liquids often are used in so-called binary bombs where two substances are mixed together and then ignited by a blasting cap or other type of detonator, he says.
Chertoff said on Cable News Network that people shouldn't think none of the detection equipment being used at U.S. airports could help in detecting liquid explosives.
``I would not make that assumption,'' he said.
Simply banning liquids, as was done for a time in Tokyo in the 1990s, won't address the threat, says Doug Laird, an aviation-security consultant in Washington who worked for the U.S. Secret Service for 20 years.
Laird called for three responses: Giving all screeners at airport checkpoints so-called CAT scanners that generate three- dimensional pictures, not just two-dimensional X-ray machines; deploying equipment capable of detecting explosives hidden in bottles; and using body scans to find liquids hidden inside someone's pocket.
``The public doesn't want body scans because they feel it's an invasion of privacy,'' Laird says. ``But the problem is you can easily hide those liquids on your person.''
Gerry Leone, the former U.S. prosecutor who handled the case against ``shoe bomber'' Richard Reid in Boston, says passengers need to consider allowing screeners to gather more information about people flying, as El Al Israel Airlines does.
``What we need is a combination of detection systems that will pick up those things that are most prevalent and cause us the most risk, combined with a more human, personal screening,'' he says.
Security companies have been developing new screening devices that can identify non-metallic materials that might be used in explosives.
``The traditional approach in airports has been to screen baggage for explosives, with passenger screening limited to metal detection and physical search,'' according to the Web site of Smiths Group Plc, a London-based aerospace-electronics maker. ``The increased threat from suicide bombers using non-metallic devices has exposed a loophole in many existing security systems.''
Smiths' detection division sells a machine called Sentinel II, which uses airflow to dislodge particles from the clothing and skin of airline passengers as they pass through the machine, providing samples to be analyzed for traces of explosives, chemicals and drugs, the company's Web site says.
It competes with General Electric Co.'s EntryScan portal, which is designed to detect traces of explosives. The machine is meant to be used in conjunction with the company's Itemiser desktop unit, thousands of which are in use in the U.S., that detects explosives on objects through the use of a swab, says Steve Hill, a spokesman for GE's Homeland Security business.
GE's InVision division makes explosives-detection machines for checked baggage and uses computed tomography to scan for densities of objects, Hill says.
`No Silver Bullet'
``No one of them is a silver bullet,'' Hill says. ``It's supposed to be a multi-layered system.''
Security checkpoints at more than 30 U.S. airports, including Dulles International in Washington, John F. Kennedy in New York and Logan International in Boston, have been equipped with the latest explosives-detection equipment from GE and Smiths Group, the Transportation Security Administration said in an Aug. 7 statement.
Each device costs about $160,000, the TSA said in the statement, which announced that the agency had deployed two such machines at Chicago's Midway International Airport.
Smiths Group on Aug. 1 said it had received a contract from the British government. The first two portals will be deployed at Heathrow and Manchester airports, it said.
The company had no comment beyond the information on its Web site, said Rachel Lankester, a spokeswoman.
`In Its Infancy'
The technology to detect traces of chemical explosives in the air is ``still in its infancy'' and is ``not foolproof,'' says Garry Hindle, head of terrorism and international homeland security at London's Royal United Services Institute.
``That's due to the nature of terrorism itself,'' he says. ``Once they're aware that people are onto it, they move to new things.''
NBC News reported in March that undercover federal investigators, acting at the request of Congress, were able to carry materials needed to make a homemade bomb through security at all 21 airports tested. Laura Kopelson, a spokeswoman for Congress's Government Accountability Office, confirmed to Bloomberg News the existence of a classified report that concluded ``there were vulnerabilities.''
New York-based TraceGuard Technologies Inc. has developed a machine called CarrySafe that can detect chemicals used in explosives on or in carry-on luggage without opening the bags, says Chairman and Chief Executive Officer Ehud Ganani. It's also working on a machine that would check for explosives in laptop computers and cameras without damaging them, he says.
Ganani, who was reached by phone, is the former CEO of Israel Military Industries Ltd., a state-owned defense contractor.
So far, no CarrySafe units have been deployed. TraceGuard is building nine machines, one for Israel's Ben Gurion Airport and the others for border crossings in Israel, Ganani says. The first devices will be tested in December, he says.
``We can detect plastic explosives down to a level of 150 micrograms, not just on the person who is carrying the explosive but for anyone who was in the vicinity when it was put together,'' he says.
Successful detection of bomb-making materials is a combination of methodology, technology and training, Ganani says.
``Unless they were made in a sterile environment, there's no such thing as a super-clean improvised explosive device,'' he says. ``They're all contaminated in some way and can be detected.''
To contact the reporter on this story: Charles Goldsmith in London at