Air Transport

The US FAA has finalized an airworthiness directive (AD) first proposed in April 2005, calling for operators of more than 600 Boeing airliners to eventually replace insulation blankets the agency says could ignite and spread fire ignited by electrical arching or sparking.

FAA estimates cost of the required work is $177.7 million fleet wide.

The AD requires removing insulation blankets coated with polyethyleneteraphthalate or Orcofilm AN-26 located in the aircraft's pressurized areas and installing new blankets. It was originally proposed after reports of in-flight and ground fires occurring on aircraft with coated insulation, says the FAA. Affected are 628 US-registered aircraft, including aircraft in the Boeing 757, 767 and 747 families.

Locations where the suspect insulation is installed include the space behind flight deck panels and circuit breaker panels, areas behind sidewalls, lavatories, closets and galleys and the cargo compartment

FAA in its final rule extends the compliance time from 72 months to 96 months beyond the 15 December effective date.