| The biggest threat facing airlines today may not be
a terrorist with a gun, but the man with the portable computer in business{{U}}
(21) {{/U}}. In the last 15 years, pilots have reported well over 100
incidents that{{U}} (22) {{/U}}by electromagnetic interference. The
source of this interference remains{{U}} (23) {{/U}}, but increasingly,
experts are pointing the blame at portable electronic devices such as portable
computers, radio and cassette players and mobile telephones. RTCA, an organization which advises the aviation industry, has recommended that all airlines ban such devices from being used during "critical" stages of flight, particularly takeoff and landing. Some experts have gone further, {{U}}(24) {{/U}}a total ban during all flights. Currently, rules on using these devices are left up to individual airlines. And although some airlines prohibit passengers from using such equipment during take-off and landing, most are reluctant to{{U}} (25) {{/U}}a total ban, {{U}}(26) {{/U}}that many passengers want to work during flights. The difficulty is predicting how electromagnetic fields might{{U}} (27) {{/U}}an aircraft's computers. Experts know that portable devices emit radiation which affects those wavelengths which aircraft use for navigation and communication. But, because they{{U}} (28) {{/U}}reproduce these effects in a laboratory, they have no way of knowing whether the interference might be dangerous or not. The fact that aircraft may be vulnerable{{U}} (29) {{/U}}interference raises the risk that terrorists may use radio systems in order to damage navigation equipment. As worrying, though, is the passenger who can't hear the instructions to{{U}} (30) {{/U}}his radio because the music’s too loud. |