Since the September 11 terrorist attacks, life has changed for American travelers. They have learned to drop off their knives on the way to the airport and to take off their shoes before reaching the security checkpoint. But the security machines at the checkpoints are not much different than they were five years ago.
That may be about to change. The Aug. 10 announcement that British authorities had arrested terrorists planning to use liquid explosives to blow up jets in the air could be a catalyst for the introduction of new devices in the U.S. airport security routine. Jack Riley, a homeland security expert with the RAND Corporation says the plot will "accelerate the rate at which these machines are implemented."
Aviation security observers see the evolution of a layered security system that will increase the use of technologies such as trace substance detectors and backscatter X-rays. Technologies that can be calibrated to detect a stunning array of substances, including liquid explosives, are already installed in some U.S. airports. However, this is far from a cure-all. Homeland Security Dept. Secretary Michael Chertoff expressed concern that the plot involved combining a number of "benign" substances on board airplanes to create bombs. Without knowing what materials were involved, it is impossible to know whether the trace detectors would have sniffed out the dangerous substances.
SOPHISTICATED DETECTION. Industrial giant General Electric (GE) and British-listed Smiths Detection each market trace portal machines, sometimes called puffers, which resemble standard metal detectors. When a passenger stands on the threshold, the machine fires brief jets of air at him and then tests for traces of explosives. The technology can also be used to detect other substances like narcotics (see BusinessWeek.com, 8/10/06, "In This War, Technology Is Key").
The puffers are already being put to work. Earlier in August, the Homeland Security Dept.'s Transportation Security Administration (TSA) said it had deployed two such devices at Chicago's Midway International Airport, one of many around the country. But they are not a first-line device: According to a statement from the administration they will be used on "passengers identified for additional screening." Midway is just one example; GE alone expects to have more than 170 in place by the end of this summer.
TSA spokeswoman Ann Davis says the passenger screening process involves flagging individuals on flight-screening lists compiled by airlines, people exhibiting odd behavior, and persons selected at random, adding another security element to the existing metal detector.
To some extent, a model of this layered security system already exists. Before check-in, passengers on Israeli flagship carrier El Al go through brief interviews and are routinely singled out for more in-depth screening, which can involve the removal of clothing, analysis of toiletries, and sipping any liquids that they may be carrying. But El Al is a tiny airline in a country where security is of unsurpassable concern; similar procedures would not necessarily be practical or desirable in the U.S. The thoroughness takes its toll: The carrier asks economy class passengers to arrive four hours before departure.
FALSE POSITIVES. As for the puffers, some are concerned that false-positive results could cause major delays in security lines, especially if they were a primary security method . Bob Mann, president of R.W. Mann, an airline industry analysis and consulting firm, says, "If I fertilized my lawn and went to the airport with the same shoes on, I'd spend the rest of the day there."
GE Security spokesman Steve Hill says the false-positive ratio is a "really low number" but declined to be more specific. The company's trace technology is more widely deployed at the checkpoints in GE's Itemiser, a device that can measure swabs taken from carry-on bags for potentially dangerous material.
Hill says the company envisions the "checkpoint of the future" to include a trace device that tests passenger fingerprints. But at present the group thinks the puffer is well suited to secondary screening.
What else is in the security arsenal? Another post-September 11 security addition is that checked luggage must also go through screening by a computed tomography (CT scan) device, basically a three-dimensional X-ray or a trace test. GE offers products for both operations. Davis says all bags receive one treatment or the other and personnel examine those that require an additional security layer.
PRIVACY CONCERNS. Another technology that could come into fashion is backscatter X-rays. Used to perform a full body scan in search of abnormalities, the tech's supporters say it's fast and able to detect everything from blades to explosives to drugs. But that's also a privacy problem: The scanners see through clothing.
OSI Systems (OSIS) subsidiary Rapiscan Systems sells a backscatter scanner that is used in some Defense Dept. facilities and as a secondary device in London's Heathrow Airport, thanks to stringent procedures designed not to embarrass passengers. Davis, of the TSA, says the agency is working with several vendors but harbors "privacy concerns."
Thanks to the backscatter scanner and other products, companies such as OSI may be positioned to gain from the ever greater desire for security. Shares in the security outfit jumped more than 9% on Aug. 10 to close at $19.14.
Not surprisingly, Riley, of RAND, says that explosive detection will be among the greatest challenges facing TSA in coming years. But even in this transitional stage in airport security, he says the arrests demonstrate that security technology is not the only part of preventing terrorism. Given the difficulty of getting a U.S. visa, he says they might not have even made it onto the planes.