Originally Posted by NG_Kaptain
Varig on July 11, 1973 crashed in Paris due to an uncontained fire in the aft lavatory, was suspected a smoker started it accidentally.
Originally Posted by NG_Kaptain
The fire may have been started by an electrical fault or by the carelessness of a passenger.
Between June 1985 and June 2002, operators of Boeing aircraft made a total of 67 reports to Boeing of heater ribbon failures where thermal degradation was evident. Charred insulation material was identified in many of the reports. Structural damage from fire had occurred in at least two cases.
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Service Difficulty Reports USA 1999042300717, USA 1988040800197, AUS 19990967, and AUS 19991248 all report burned heater ribbons.
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The above information concerning heater ribbon failures supports the existence of an unsafe condition relating to the potential for water line heater ribbon installations to provide a source of ignition, combined with the availability of flammable materials in sufficiently close proximity to the ignition source to ignite. Heater ribbons are used extensively in transport category aircraft, including Boeing 707
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In-line water heaters and water lines that contain integral heating elements are more prevalent on newer generation aircraft. Although historical data is limited, the possible failure modes of in-line and integral water heaters are considered to present a much lower threat of ignition than those associated with external heater ribbons.
TSB Aviation Safety Recommendations