Passengers will be able to use mobile phones on aircraft soon

New technology will soon allow passengers to make phone calls on mobile handsets safely while in flight. At present, industry safety regulators have banned the use of mobiles on planes, because the signal could interfere with the plane's electronic and communications equipment.

Air France is expected to be the first to make the service available, later this year.

Earlier this week, British budget carrier Ryanair started trials using mobile phones on Boeing 737 planes, which are used for millions of short-haul flights a year. If the trials are successful, the no-frills carrier says it can offer the facility on most of its planes as early as December 2008.

The technology has to be approved by the European Aviation Safety Agency as well as other safety regulators. Once approval is given, it will be possible to use phones above 10,000 feet, the altitude at which computers and other electronic devices can safely be switched on.

Key to the new technology is a small telephone mast, about the size of a dinner plate, which keeps the phone signal weak, so it cannot interfere with other equipment on the plane. Once boosted by the mini-mast, it becomes strong enough to make a call. Without the mast, the phone signal was too strong because it sought the nearest mast, normally on the ground more than 30,000ft below.