CIVIL AVIATION AUTHORITY (CAA) research would seem to prove that mobile telephone transmissions made by airline passengers can interfere with aircraft equipment. The CAA has undertaken tests that support the existing ban on the use of mobile telephones on board aircraft when the aircraft doors are closed for flight. This has been in effect since the widespread introduction of mobile telephones and was supported by initial research performed in February 2000. The latest study found that the use of mobile telephones can adversely affect navigation and communication functions, producing significant errors on instrument displays and background noise on audio outputs. http://www.caa.co.uk