The communication cards had been removed from the cell phones attached to the bombs, meaning the phones could not receive calls, officials said, making it likely the terrorists intended the alarm or timer functions to detonate the bombs.

“The cell phone probably would have been triggered by the alarm functions and it would have exploded midair,” said a U.S. official briefed on the investigation of the bombs taken off cargo planes Friday in England and the United Arab Emirates. This person, like other officials in this story, spoke on condition of anonymity to discuss the case…

While a test run would have given al-Qaida a sense of the shipping routes, there was no guarantee the route would be the same a month — or even a day — later, officials at UPS and FedEx said Tuesday. Routes change based on the weather, cargo volume and plane schedules, they said.