In addition to Newark Liberty, other airports where puff portals were deployed include John F. Kennedy International, Boston Logan International, Los Angeles International, Miami International and San Francisco International.
In its recent report, the GAO, which is the investigative arm of Congress, determined "limited progress has been made in fielding explosives detection technology at passenger screening checkpoints."
That blunt assessment came six months after the nation's aviation-security system placed unprecedented focus on bomb detection, following the August 2006 disruption of an alleged plot by terrorists to use liquid explosives to blow up planes traveling from Great Britain to the United States.
"Due to performance and maintenance issues, TSA halted the acquisition and deployment of the [puff] portals in June 2006, and the acquisition of additional portals is contingent on resolution of these issues," the GAO also found in its report.
"It's probably DOA," said Mike Boyd, a Denver-based aviation consultant and longtime TSA critic, of the puff portal program. "This is another example of them spending a lot of money on technology they're unsure of and then mothballing [it]."
Charles Slepian, chief executive officer of the Foreseeable Risk Analysis Center, a consulting firm in New York, questioned the overall value of puff portals, even without all the problems.
Slepian called the device "the sloppy terrorist-detection machine" because it requires would-be bombers to leave traces of explosives on their body or clothes for authorities to discover a bomb. He also said he is not surprised the agency continues to say it is studying the program, rather than admitting to a mistake.
"Nobody wants to take responsibility for having supported this project in the first place," said Slepian. "Accountability just isn't in the lexicon of the TSA."
Detecting explosives at checkpoints remains among the most nettlesome areas for TSA, which federalized aviation security from a private contractor system after the Sept. 11 terrorist attacks.
Walk-through metal detectors are essentially useless against plastic and liquid explosives. X-ray machines at the checkpoint are more helpful for alert screeners because they can show the outlines of bottles and potential bombs, wires and detonators. Additionally, if a screener has reason for concern, he or she can swipe a bag with a cloth that is then tested electronically for explosives.
But the current system has produced spotty results in tests.
In October, for example, screeners at Newark Liberty failed 20 of 22 undercover security tests by U.S. agents, missing mostly concealed fake bombs at the checkpoints, according to federal security officials familiar with the results.
Tests for explosives and weapons at other major airports also have produced consistently poor results, the GAO has found in various reports.
White, the TSA spokesman, declined to detail what steps the agency has taken to make up for the loss of puff portals and help ensure passenger safety, writing only, "TSA has a layered approach to security."
On May 22, however, the TSA issued a news release announcing a pilot program testing a hand-held scanning device with "a technology capable of screening sealed bottled liquids for explosives." Newark Liberty was among a half-dozen airports where the unit has been tested, according to TSA.
"Because the technology is performing well in pilot testing, TSA anticipates deploying up to 200 bottled liquid scanners to the nation's busiest airports" by October, the agency said in its release.
Steve Elson, a former member of the Federal Aviation Administration's Red Team that found serious lapses in airport security before Sept. 11, said he is hopeful the new scanners will prove valuable in the fight against aviation terrorists.
As for the puff portals, Elson said, "The idea is good but they have to work. That's the part they always miss at the TSA."
What: The idea is that when a passenger steps inside the puff portal, the machine sends bursts of air to dislodge particles from the body, hair and clothing, and analyzes them for traces of explosives.
Cost: $160,000 each. A $30 million pilot program includes purchase, installation and maintenance.
By the end of September, TSA plans to deploy this technology to airports in N.C.; Texas; Fla.; New York; Pa.; Puerto Rico, and Washington, D.C.
In order to measure the effectiveness, operability, and functionality of a technology it must be tested in a real-world environment.
The Jersey airport gets the latest in explosive detection technology.
Two trace portals are being added at Dallas/Ft. Worth International Airport.