Swissair has confirmed that the same kind of insulation implicated in fires on four other aircraft was used on the MD-11 that crashed last month off Nova Scotia. The plane's manufacturer had recommended that the insulation be replaced.

McDonnell Douglas Corp. warned last year that the thermal insulation blankets should be replaced by a more fire-retardant type at "the earliest possible maintenance period."

Boeing Co., which now owns McDonnell Douglas, says 1,000 MD-11s were originally equipped with the metalized Mylar insulation.

The company told the Washington Post it doesn't know how many have since been retrofitted with a different type.

But Jim Harris, a spokesman for Canada's Transportation Safety Board, told the newspaper that a small amount of both types of insulation had been found in the wreckage of Swissair Flight 111.

Swissair spokesman Erwin Schaerer has confirmed metalized Mylar was used on the plane.

Officials have determined that the same insulation allowed the quick spread of fires started by electrical shorts on three aircraft from 1993 to 1995. All fires occurred on the ground and no one was injured.