The terrorists behind the airline ink bomb plot could not have known exactly where their packages were when they were set to explode, even after a suspected test run, US security sources said today.
They dismissed reports the bombs were designed to be exploded as cargo planes arrived over densely-populated parts of Chicago, their destination.
The communication cards had been removed from the mobile phones attached to the bombs, meaning they could not receive calls, making it likely the terrorists intended the alarm or timer functions to detonate the bombs.
“The phone probably would have been triggered by the alarm functions and it would have exploded midair,” said a source.
He added that each bomb was attached to a syringe containing lead azide, a chemical initiator that would have detonated PETN explosives packed into each computer printer toner cartridge.
Both PETN and a syringe were used in the failed Christmas Day underpants bomb on a Detroit-bound airliner linked to an al Qaida branch in Yemen.
The Obama administration, which has been monitoring intelligence on possible mail plots since at least early September, was preparing new security rules for international cargo in response to the attempted attack.
Security officials are considering requiring that companies provide information about incoming cargo before planes take off. Currently, the US does not get that information until four hours before a plane lands.
The US may also expand its definition of high-risk cargo, meaning more cargo will be screened from countries known as hotbeds of terrorism.
Investigators believe al Qaida sent three innocent-looking packages from Yemen to Chicago in mid-September to watch the route they took.
One of those packages contained a copy of British author George Eliot’s 1860 novel “The Mill on the Floss.” Authorities were investigating whether it was a subtle calling card from Anwar al-Awlaki, the US-born Yemeni cleric who has inspired a string of attempted attacks against the West.
The militant cleric is now a fugitive, targeted by a US kill or capture list. Yemeni authorities put him on trial in his absence yesterday, charging him as a new defendant in the October killing of a French security guard.
Al-Awlaki became well versed in English literature while in prison in Yemen from 2006 to 2007 and later posted online book reviews slamming Shakespeare and praising Charles Dickens. Beyond that, however, there was no immediate connection between al-Awlaki and the book found in the package mailed in September, one US official said.
Carriers allow internet users to monitor packages from point to point through the international cargo system.
While a test run would have given al Qaida a sense of the routes, there was no guarantee the route would be the same a month – or even a day – later. Routes change based on the weather, cargo volume and plane schedules.
Neither UPS or FedEx lets customers know precisely which planes their packages are on.
Sometimes they are packed on cargo planes, sometimes on passenger planes. There is no way for customers to track their packages in real time while in flight, officials with both companies said.
However knowing the time shipments were logged in leaving Europe and the time they were scanned arriving in Chicago would have given al Qaida operatives a large enough time window to allow them to have rigged their bombs to blow up somewhere along the way.