Airlines are buying giant X-ray machines and other machinery to meet an Aug. 1 deadline to begin screening all cargo that goes on passenger planes.
Federal officials say the new rules will close a large security gap. Just four years ago, only half of all cargo was inspected.
But the system to guard against terrorists getting a bomb on a plane is far from airtight. Cargo coming into the U.S. from other countries is still often not inspected.
In a sweltering warehouse next to Dallas-Fort Worth International Airport on Friday, American Airlines workers were being trained in the use of a 12-foot-high black box, an X-ray machine that was installed just two weeks ago.
Nearby, another airline employee traced a wand over boxes, looking for traces of explosives. The worker said fertilizer sometimes triggers an alarm.
To reduce the load on airlines, about half of all domestic cargo is being screened at more than 800 facilities run by companies certified by the Transportation Security Administration. The TSA relies on those operators to ensure that cargo isn't opened before reaching the airport.
Without those 800 centers taking half the load, it would take American hours longer to screen each cargo shipment. It also would force shippers to deliver their goods to the airport several hours earlier, defeating the advantage of speedy air freight, said Dave Brooks, president of American's cargo division.
For cargo that American screens, the airline is raising its charge and forcing shippers to get to the airport two hours earlier, starting Aug. 1.
Douglas Brittin, general manager of the TSA's cargo division, said security of cargo aboard passenger planes — long identified as a threat — has steadily improved. Since the beginning of 2009, the TSA has approved 77 new pieces of equipment to screen cargo for explosives, chemicals and other threats.
Last month, the Government Accountability Office said the TSA was making progress toward the requirement to screen all cargo on passenger planes. But the GAO said the TSA could lack resources to properly monitor those 800 independent inspection centers, and had no technology for inspecting large shipments consisting of many packages.
The TSA is talking to aviation officials in other countries to close another gap — cargo on planes arriving in the U.S. from other countries. The TSA's top official told Congress in March that it could be years before all inbound cargo is screened.
Inbound shipments that the TSA deems high risk — officials won't say how they decide — must be screened before the plane heads for the U.S. In other cases, shipments must be inspected after landing in the U.S. before being loaded on another plane.
For example, if the airline can't prove that produce being shipped from South America to Japan through the U.S. has been screened to TSA standards, "they're going to have to take it apart and screen it before it flies to Japan," Brittin said.