Swissair has voluntarily disconnected the in-flight entertainment systems on its Boeing 747 and MD-11 fleets as a precaution because some heat-damaged wiring associated with it has been found in the MD-11 which crashed off Nova Scotia, Canada, on 2 September.
Both the airline and the Transportation Safety Board of Canada (TSBC) emphasise that no positive link has been established between the in-flight entertainment power supplies and the accident.
"Technical examination of recovered materials from Swissair flight 111 has revealed that some of the wiring and structure, located in the ceiling in the vicinity of the cockpit, shows signs of heat damage. Some of this wiring is associated with the in-flight entertainment system," comments the TSBC.
Swissair is "-believed to be" alone in operating the Interactive Flight Technologies (IFT) in-flight entertainment network, says the TSBC. Alitalia had fitted the IFT system to five of its MD-11s, but it is not operational. Swissair says it is a reliable system. IFT says that the TSBC has told it that there is no indication of any malfunction or failure in its system, adding that IFT is working with the agency and Swissair to "address concerns" and allow reactivation of the system as soon as possible.
Clues from the cockpit and avionics bay, however, are elusive, says the TSBC, because the wreckage from the front of the aircraft is in small pieces, averaging "about the size of a dollar coin".
All three Pratt & Whitney PW4000s have been recovered, however, together with the full authority digital engine control on No 2, from which investigators hope to gain information.
Source: Flight International
