Cellphones have been restricted in the air for two main reasons: Phone signals may interfere with a plane's navigational equipment, and the calls could wreak havoc on regular wireless networks, which weren't designed for in-flight use. A cellphone used while airborne has a much greater transmitting range than one on the ground.

But officials say they're confident they have interference problems licked.

"There's no danger whatsoever to the aircraft," Qualcomm's Dr. Jacobs said.

To deal with the disruption issue, the airline installed a "picocell" device in the plane that directs call traffic to and from satellites, bypassing cell towers on the ground.