Missing Plane, Pilot Baffle Investigators

April 19 -- Ben Charles Padilla, an aircraft mechanic, flight engineer and cargo pilot, traveled the world plying his trade for various private companies.

He'd often keep in touch with family members from faraway locales, so it was no surprise in May 2003 when he replied to an e-mail about his mother having a heart attack with news that he was in Africa refurbishing a plane and would contact her as soon as he could.

His family has not heard from him since, and the FBI believes the 51-year-old was aboard a Boeing 727 that took off without authorization from an airport in Angola on May 25 and promptly vanished. At the time, U.S. officials told ABCNEWS they suspected the plane was stolen to run drugs or guns, and some theorized it was crashed for insurance money.

Though there was fear that the former passenger plane, which the FBI says was reconfigured to carry diesel fuel, could be in the hands of terrorists eyeing a Sept. 11-style attack, there was no evidence to link it to terrorism.

The incident touched off an intensive investigation by U.S. intelligence agencies that continues nearly a year later. The plane and Padilla remain unaccounted for — and the mysterious circumstances around their disappearance leave many unanswered questions.

How could a plane vanish? Who has it now? And what happened to Padilla, who was no stranger to assignments like the one that took him to Angola?

Waiting for a Break

"It's been almost a year and I know really no more now than I did in the beginning," said Joseph Padilla of Pensacola, Fla., younger brother of the missing man. Family members are baffled by his disappearance but maintain Ben Padilla would not knowingly have been involved in any illegal activities.

Joseph Padilla suspects there may have been some sort of dispute of ownership between the company that hired his brother and someone else, and that Ben got caught in the middle.

Joseph Padilla stays in contact with the FBI and State Department for updates on the case and provides them with leads from reporters and his own research.