FAA Requires Inspection of DC-9/MD-88 and MD-90 Port Heaters and Insulation

WASHINGTON - The Federal Aviation Administration (FAA) has
ordered operators of DC-9/MD-88 series and MD-90-30 series
aircraft to inspect the wiring of static port heaters for chafing,
loose connections and evidence of arcing, and to make necessary
repairs. Operators must also determine if the surrounding
insulation is covered with metalized Mylar™
(polyethyleneteraphthalate). If so, the Mylar™ must be removed
and/or replaced with Tedlar™-covered insulation, or other
appropriate action must be taken. Static port heaters are small
heaters that keep ice from forming on devices that measure air
pressure.

The immediately adopted airworthiness directive (AD) is in
response to an incident that occurred on Sept. 17, 1999, in which a
Delta Air Lines MD-88 experienced a fire in the forward cargo
compartment shortly after takeoff from Northern Kentucky
International Airport in Covington, Ky. The plane returned to the
airport without passenger injuries. In its investigation, the National
Transportation Safety Board (NTSB) determined that a spark from
a static port heater ignited the fire, which spread by consuming
the metalized Mylar™ insulation surrounding the heater.

The AD will affect 593 U.S.-registered DC-9-81, -82, -83, -87 and
MD-88 aircraft, as well as 12 MD-90-30s. U.S. operators affected,
in addition to Delta, are Alaska Airlines, American Airlines,
Continental Airlines, Midwest Express Airlines, Trans World Airlines
and US Airways. The total cost per aircraft is estimated at $120.