Airworthiness Directive · Amendment 39-10666 · McDonnell Douglas Model DC-9, DC-9-80, and C-9 (Military) Series Airplanes, and Model MD-88 Airplanes
McDonnell Douglas Model DC-9, DC-9-80, and C-9 (Military) Series Airplanes, and Model MD-88 Airplanes
Model DC-9-30, -40, and -50 series airplanes; Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) series airplanes; Model MD-88 airplanes; and C-9 (military) series airplanes; as listed in McDonnell Douglas Service Bulletin DC9-26-025, Revision 04, dated April 30, 1997; certificated in any category.
This amendment supersedes an existing airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9, DC-9-80, and C-9 (military) series airplanes, and Model MD-88 airplanes, that currently requires an inspection to detect chafing on the FIREX pipe assembly of the number one engine; and either repair of chafed pipe assemblies or replacement of the chafed pipe assemblies with new pipe assemblies; and modification of the FIREX and the pneumatic sense pipe assembly clamp marriage. This amendment revises the applicability of the existing AD to include additional airplanes and remove others. This amendment is prompted by reports of incidents in which the pneumatic sense pipe chafed against the FIREX supply pipe of the number one engine. The actions specified by this AD are intended to prevent chafing of the FIREX supply pipe, which could result in a hole in the pipe and consequently prevent the proper distribution of the fire extinguishing agent within the nacelle in the event of a fire.
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.
