Airworthiness Directive · Amendment 39-9798 · The Boeing Company Airplanes
The Boeing Company Airplanes
This AD applies to The Boeing Company DC-9-11, DC-9-12, DC-9-13, DC-9-14, DC-9-15, DC-9-15F, DC-9-21, DC-9-31, DC-9-32, DC-9-32 (VC-9C), DC-9-32F, DC-9-32F (C-9A), DC-9-32F (C-9B), DC-9-33F, DC-9-34, DC-9-34F, DC-9-41, DC-9-51, DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), MD-88.
The models as the FAA's AD index lists them. The serial ranges, installed parts and exceptions are in the AD itself: read it at the FAA.
This amendment adopts a new airworthiness directive (AD), applicable to all McDonnell Douglas DC-9 and DC-9-80 series airplanes, and Model MD-88 airplanes, that requires repetitive leak checks of the lavatory drain system and repair, if necessary; provides for the option of revising the FAA-approved maintenance program to include a schedule of leak checks; requires the installation of a cap on the flush/fill line; and requires replacement or modification of the vent system piping. This amendment is prompted by continuing reports of damage to engines and airframes, separation of engines from airplanes, and damage to property on the ground, caused by "blue ice" that forms from leaking lavatory drain systems on transport category airplanes and subsequently dislodges from the airplane fuselage. The actions specified by this AD are intended to prevent such damage associated with the problems of "blue ice."
