A generic human-shaped outline will replace live images of naked people in airport body scanners located in Las Vegas's McCarran airport under a pilot project announced Feb. 1 by the Transportation Security Administration.

Although TSA has maintained that the impact of the full-body scanners is "minimal," TSA Administrator John Pistole nonetheless said it is testing software that displays an identical human form rather than the actual image of a person who steps into an millimeter wave scanning booth. The pilot is set to expand to the Hartsfield-Jackson Atlanta airport and Washington, D.C.'s Reagan National Airport in the coming days. So far it is limited to millimeter wave machines and not backscatter scanners.

The software doesn't prevent the millimeter wave machines from taking a clothes-penetrating picture of the person inside the booth, but substitutes a generic figure on the display screen. The software is meant to automatically detect potential threats, and if none are found, display "OK" on the monitor.

TSA says that because the pilot scanners no longer display images of naked people, TSA officials monitoring machines loaded with the test software won't be sequestered to a remote-located viewing room, a fact that TSA says should make security lines move faster. The trial will last up to 60 days.

TSA has deployed almost 500 body scanners at 78 airports, according to government figures. Their effectiveness has been called into question, however, most recently by a study printed in the Journal of Transportation Security, which outlines how terrorists might beat the backscatter machines by flattening the explosive PETN into an "irregularly-shaped cm-thick pancake with beveled edges, taped to the abdomen." Such a pancake consisting of 40 grams of PETN would be "virtually invisible" since it would be easily confused with normal anatomy, says the study, which is by two professors at the University of California-San Francisco, Leon Kaufman and Joseph W. Carlson.

Objects such as a wire or even a small gun could also escape backscatter detection were it taped to the side of the body, states a The Economist study summary.

For more:
- read a TSA press release on the pilot
- go to The Economist study summary

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