Independent aviation data specialist John King has found more than 50 cases of significant system failures, smoke or fires involving cabin entertainment from 1988-2001, for an average incident rate of about four per year. A few are cited to illustrate the typical contents of these reports.

"Of course, all aircraft systems were designed and certified by the FAA and should not emit smoke or cause fires because proper circuit design expressly is supposed to stop this. The purpose of circuit breakers is not to protect the equipment but rather to prevent electrical overloads and wire overheating," King said.

He believes the frequency of these incidents is undercounted. "The FAA office of system safety databases provided only about 10 percent of the reports, as compared to direct accounts from pilots to the Aviation Safety Reporting System (ASRS), or from maintenance in the service difficulty reports (SDRs)," King added. >> King, e-mail jking1@attbi.com <<