Airworthiness Directive · Amendment 39-11749 · McDonnell Douglas Model DC-9-80 and MD-90-30 Series Airplanes, and Model MD-88 Airplanes
McDonnell Douglas Model DC-9-80 and MD-90-30 Series Airplanes, and Model MD-88 Airplanes
Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87) series airplanes; Model MD-90-30 series airplanes; and Model MD-88 airplanes; manufacturer's fuselage numbers 995 through 2243 inclusive; certificated in any category.
Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (e) of this AD. The request should include an assessment of this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9-80 and MD-90-30 series airplanes, and Model MD-88 airplanes, that requires a determination be made of whether, and at what locations, metallized polyethyleneteraphthalate (MPET) insulation blankets are installed, and replacement of MPET insulation blankets with new insulation blankets. This amendment is prompted by reports of in-flight and ground fires on certain airplanes manufactured with insulation blankets covered with MPET, which may contribute to the spread of a fire when ignition occurs from small ignition sources such as electrical arcing or sparking. The actions specified by this AD are intended to ensure that insulation blankets constructed of MPET are removed from the fuselage. Such insulation blankets could propagate a small fire that is the result of an otherwise harmless electrical arc and could lead to a much larger fire.
To ensure that insulation blankets constructed of metallized polyethyleneteraphthalate (MPET) are removed from the fuselage, accomplish the following:
(a) Within 5 years after the effective date of this AD, determine whether, and at what locations, insulation blankets constructed of MPET, are installed. When markings are not visible, the determination shall be made by using known MPET material as a comparison sample to assist in the identification.
Note 2: Insulation blankets that are marked with “DMS 2072, Type 2, Class 1, Grade A;” “DMS 2072, Type 2, Class 1;” or “DMS 1996, Type 1;” are constructed of MPET.
(b) For insulation blankets that are determined not to be constructed of MPET, no further action is required by this AD.
(c) For insulation blankets that are determined to be constructed of MPET, within 5 years after the effective date of this AD, replace the MPET insulation blankets with new insulation blankets that have been approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. The blankets shall be replaced in accordance with the Accomplishment Instructions of McDonnell Douglas Service Bulletin MD-90-25-015, Revision 01, dated November 5, 1997 (for Model MD-90-30 series airplanes); or McDonnell Douglas Service Bulletin MD80-25-355, Revision 01, dated November 5, 1997 (for Model DC-9-80 series airplanes and Model MD-88 airplanes); as applicable. The replacement insulation blankets must be constructed of materials tested in accordance with Appendix 1 of this AD, or in accordance with a method approved by the Manager, Los Angeles ACO.
Note 3: Although this paragraph allows up to 5 years for the required replacement, the FAA anticipates that operators will comply at the earliest practicable maintenance opportunity.
Note 4: Only one of the two metallized Tedlar TM covers specified in the service bulletins has been shown to have successfully passed the testing of the American Society for Testing and Materials (ASTM) flammability standard and is considered acceptable for compliance with the requirements of paragraph (c) of this AD.
(d) As of the effective date of this AD, no person shall install an MPET insulation blanket on any airplane.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
