Swissair is to replace Mylar insulation on the cockpit and some cabin sections of its Boeing MD-11s with a more fire-resistant material called Tedlar.

"This task is being undertaken at Swissair's initiative based on information gathered in the investigation into the cause of last year's SR 111 accident," says the airline.

The insulation will be installed during routine heavy maintenance of Swissair's MD-11s, with the first modified aircraft due to re-enter service this month. Swissair says the work has been performed in co-operation with Boeing, which intends to draft recommendations and documentation to aid other operators planning to follow suit.

Insulation blankets recovered from the wreckage of SR 111 which crashed last year off Nova Scotia with the loss of all crew and passengers showed evidence of severe heat stress, suggesting that "Mylar would not sufficiently impede the spread of fire" says Swissair.

Mylar meets current regulatory requirements though the US Federal Aviation Authority is considering mandating the replacement of Mylar blankets over four years.

The SFr200,000 ($130,000) cost of replacing the insulation blankets has been shared by the airline and Boeing. Earlier this year Swissair ordered CTT Zonal Drying Systems for its MD-11 fleet to combat the build-up of condensation in the insulation blankets.

Source: Flight International