Full-body scans and aggressive pat-downs now under scrutiny are designed to seek out the explosive powder that was used in several failed terrorist bombings recently, officials say.RELATED: At The Hill, "Next step for body scanners could be trains, boats, metro" (via Memeorandum).
New airport security procedures that have stirred the emotions of air travelers — full-body scans and aggressive pat-downs — were largely designed to detect an explosive powder called PETN, which has been a staple of Al Qaeda bomb makers for nearly a decade.
It was PETN that was molded into the sole of Richard Reid's black high-top sneaker when he walked onto American Airlines Flight 63 bound for Miami in December 2001.
It was PETN that was sewn into the underwear of Umar Farouk Abdulmutallab, authorities say, when he boarded Northwest Airlines Flight 253 for Detroit on Christmas Day 2009.
And it was PETN that suspected Al Qaeda operatives in Yemen packed inside computer printer cartridges that were shipped Oct. 28, intending to blow up planes en route to Chicago.
None of the plots succeeded in taking down an aircraft, but top U.S. officials are concerned about fresh indications that Al Qaeda remains determined to get PETN on airplanes by trying to exploit vulnerabilities in passenger and cargo screening.
Not only has the terrorist network acknowledged its role in bomb plots, it is also sharing what it knows about building bombs on the Web and elsewhere.
PETN, or pentaerythritol tetranitrate, presents some vexing problems for security experts. A powder about the consistency of fine popcorn salt, it will not trigger an alarm on a metal detector. Because of its more stable molecules, PETN gives off less vapor, making it more difficult to detect by bomb-sniffing dogs and the trace swabs used by the Transportation Security Administration.
PETN's stability makes it easy to hide and easily transformed. When mixed with rubber cement or putty, it becomes a rudimentary plastic explosive — a baseball-sized amount can blow a hole in an airplane fuselage.
"PETN is hard to detect and lends itself to being concealed," said an intelligence official who was not authorized to speak on the record. "It packs a punch."