Currently, Rapiscan is playing catch up, but the company is expected to release its own ATR software soon. “When privacy enhancing software being developed for backscatter units meets TSA’s detection standards, TSA will test it in the airport environment,” says Riley. “TSA anticipates testing this software for backscatter units at airports this fall.”
The choice of technology is also affected by the x-ray health concerns, especially after the EU backscatter ban. L-3’s active millimeter wave scanners have also been approved for use in other countries’ airports, including Australia, Canada, Italy, the Netherlands, and Russia, giving it an advantage over its main competitor.
But L-3’s millimeter wave machines have been plagued by problems too. During recent tests of the machines, France and Germany decided against using them because of an unacceptable level of false alarms, ranging from 23 to 54 percent, according to an investigation by ProPublica. Tests of ATR-enhanced machines have found that pockets, zippers, and buttons on clothing; layered clothing or folds in clothing; and even sweat patterns trigger false alarms.
William Frain, a senior vice president at L-3, says the problems probably occurred due to outdated software. Once the machines receive the necessary software upgrades and are retested by those governments, Frain believes that France and Germany will approve the machines. (Rapiscan’s system only registers a false alarm rate of 5 percent, but the absence of ATR and the presence of ionizing radiation have made it a less attractive technology for passenger screening.)
Skeptics also argue that terrorists can beat the machines. In March 2010, Steve Lord, the Government Accountability Office’s director of homeland security and justice issues, told Congress that he was unsure whether an active millimeter wave machine would have detected Umar Farouk Abdulmutallab’s underwear bomb on Christmas Day 2009.
Then in the March 2011 issue of the Journal of Transportation Security, researchers demonstrated that terrorists had a good chance of getting the explosive PETN, the same kind used by Abdulmutallab, past backscatter machines without detection. “It is very likely that a large (15–20 cm in diameter), irregularly-shaped, cm-thick pancake with beveled edges, taped to the abdomen, would be invisible to this technology, ironically, because of its large volume, since it is easily confused with normal anatomy,” researchers Leon Kaufman and Joseph W. Carlson wrote. “Thus, a third of a kilo of PETN, easily picked up in a competent pat down, would be missed by backscatter ‘high technology.’”