The nation's next terrorism scare could come from the bellies of U.S. commercial jetliners, security experts say.
Each day, millions of pounds of air cargo are loaded into the holds of passenger planes at more than 400 airports nationwide. Yet, unlike travelers' checked baggage, freight is rarely screened electronically for explosives.
The U.S. Transportation Security Administration requires that air cargo be sent by "a known shipper" with a history of sending packages, boxes and crates without incident. However, only a small percentage of that freight is randomly checked by airline personnel before it is loaded onto the same planes with travelers who have been screened.
"Most of (the cargo) is inspected privately. We don't know who's looking at some of the stuff," said Tom Kean Sr., the former New Jersey governor who chaired the 9/11 Commission. "Air cargo is obviously a real problem and ought to be addressed."
Renewed concerns about air cargo security are being raised in the wake of last week's foiled plot by alleged terrorists intent on using liquid explosives to blow up planes bound for the U.S. from Great Britain. The concerns about air cargo center more on plastic or powder explosives that can be set off by a timing device.
TSA officials say they are trying to better scrutinize air freight, but concede their efforts have been limited.
"It's not technically feasible to screen 100 percent of air cargo at this time. The technology does not exist," said Ann Davis, a TSA spokeswoman. Physically searching each package, box or crate of freight would be too time-consuming and "impede the flow of commerce," she said.
Air cargo represents a critical source of revenue for financially strapped commercial airlines, but security experts call it a major risk most passengers aren't even aware of.
Airlines inspect a small percentage of cargo by various means, including checking shipping manifests, visual checks or, in some cases, by physically opening boxes. TSA personnel are required to monitor some of those inspections.
