Airworthiness Directive · Amendment 39-11849 · McDonnell Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87); Model MD-88 Airplanes; and Model MD-90-30 Series Airplanes
McDonnell Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87); Model MD-88 Airplanes; and Model MD-90-30 Series Airplanes
Models and series of airplanes as listed in the applicable McDonnell Douglas service bulletin(s) specified in Table 1 of this AD, certificated in any category.
| Model of airplane | McDonnell Douglas Service Bulletin(s) |
|---|---|
| DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) series airplanes | MD80-29-056, dated June 18, 1996; MD80-29-062, Revision 01, dated August 3, 1999; and MD80-53-286, dated September 3, 1999. |
| MD-88 airplanes | MD80-29-062, Revision 01, dated August 3, 1999; and MD80-53-286, dated September 3, 1999. |
| MD-90-30 series airplanes | MD90-53-018, dated September 3, 1999. |
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 the effect of the modification, alteration, or repair on the unsafe condition addressed by 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-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87); Model MD-88 airplanes; and Model MD-90-30 series airplanes; that requires installation of a pipe support and clamps on the hydraulic lines in the aft fuselage; replacement of the hydraulic pipe assembly in the aft fuselage with a new pipe assembly; and installation of drain tube assemblies and diverter assemblies in the area of the auxiliary power unit (APU) inlet; as applicable. This amendment is prompted by reports of smoke and odor in the passenger cabin and cockpit due to hydraulic fluid leaking into the APU inlet, and subsequently, into the air conditioning system. The actions specified by this AD are intended to prevent such hydraulic fluid leakage due to fatigue vibration and cracking in the flared radius of a hydraulic pipe in the aft fuselage, which could result in smoke and odors in the passenger cabin or cockpit.
To prevent hydraulic fluid leakage into the auxiliary power unit (APU) inlet due to fatigue vibration and cracking in the flared radius of a hydraulic pipe in the aft fuselage, which could result in smoke and odors in the passenger cabin or cockpit; accomplish the following:
(a) For Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) series airplanes, as listed in McDonnell Douglas Service Bulletin MD80-29-056, dated June 18, 1996: Within 18 months after the effective date of this AD, install a pipe support and clamps on the hydraulic lines in the aft fuselage in accordance with the service bulletin.
(b) For Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) series airplanes, and Model MD-88 airplanes, as listed McDonnell Douglas Service Bulletin MD80-29-062, Revision 01, dated August 3, 1999: Within 18 months after the effective date of this AD, replace the hydraulic pipe assembly in the aft fuselage with a new pipe assembly having a greater wall thickness, in accordance with the service bulletin. Except for Model MD-88 airplanes that have been modified in accordance with McDonnell Douglas MD-80 Service Bulletin 29-54, dated February 2, 1993, or Revision 2, dated December 17, 1993, the requirements of this paragraph must be accomplished concurrently with the requirements of paragraph (a) of this AD.
(c) For Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) series airplanes, as listed in McDonnell Douglas Service Bulletin MD80-53-286, dated September 3, 1999; and Model MD-90-30 series airplanes, as listed in McDonnell Douglas Service Bulletin MD90-53-018, dated September 3, 1999: Within 36 months after the effective date of this AD, install drain tube assemblies and diverter assemblies in the area of the APU inlet, in accordance with the applicable service bulletin.
(d) As of the effective date of this AD, no person shall install a hydraulic pipe assembly, part number 7936907-603, 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.
