Originally Posted by rickair7777

Different systems may handle roaming differently. It may attempt to contact the phone via it's last know cell, and may generate a ring-tone while it's doing that. The ring tone doesn't always mean the phone is ringing, it may just mean the system is looking for a phone that never "checked out" of a cell.

If you turn your phone off, it should check out and the system would know it was off until it checked back in. But if the phone was left on for TO and just flew out of range, the cell at the airport might assume it's still there.

I wouldn't read ANYTHING into this until authorities do some forensics on what exactly the cell system was doing.