Mobile telephone ban on flights set to continue.

The ban on the use of mobile phones by passengers on planes is set to continue, aviation regulators said yesterday.

New tests by the Civil Aviation Authority confirmed that phones are still a threat to aircraft.

The latest study found that the use of mobile phones can adversely affect navigation and communication functions, producing significant errors on instrument displays and background noise on audio outputs. The CAA study recommended that as well as the usual on-board warnings about the use of mobiles, there should also be reminder notices in airport departure lounges and warnings by check-in staff.

The research backs up reports from pilots, who have stated that interference from mobiles has caused:

* False notification of unsafe conditions - for example, incorrect baggage compartment smoke alarm warnings;

* Malfunction of aircraft systems;

* Interrupted communications due to noise in the flight crew headphones

* Distraction of crews from their normal duties due to increased work levels and the possibility of having to invoke emergency drills.

Dan Hawkes, an avionics specialist at the CAA, said: "The tests demonstrate that mobile telephone use near an aircraft's flight deck or avionics equipment bay can adversely affect systems that are essential for safe flight."