§ Mrs. Dunwoody
To ask the Secretary of State for the Environment, Transport and the Regions what action the Civil Aviation Authority is taking following reports on incidents involving electronic equipment interfering with flight equipment. 
§ Ms Glenda Jackson
[holding answer 18 March 1998]: The Civil Aviation Authority requires all aircraft systems and equipment to have a high degree of immunity from interference. In the reported cases of possible interference from 'passenger carry on electronic devices' (PEDs) it has not been possible to reproduce or substantiate the reported effects. While these incidents are more of a nuisance than a hazard, they are taken seriously by CAA. The CAA has consequently issued specific information and instructions to aircraft operators regarding the use of mobile phones and PEDs in Aeronautical Information Circulars and a Notice to Air Operator Certificate Holders. However, it remains the responsibility of the aircraft operator to ensure that any equipment carried on or stowed in the aircraft cannot impair the airworthiness of the aircraft.
In addition, the CAA has initiated research through the Defence Evaluation Research Agency's Electro Magnetic Compatibility Club. This research is comparing the levels and frequencies of the signals produced by PEDs with aircraft systems and the equipment interference immunity and susceptibility standards with the aim of establishing whether any coupling to aircraft systems could occur. While the research is not yet complete, the indications are that PEDs cannot interfere with flight safety and management systems but there may be a theoretical possibility of indirect coupling to VHF radio equipment.