Airworthiness Directive · Amendment 39-9777 · McDonnell Douglas Corporation Airplanes
McDonnell Douglas Corporation Airplanes
Superseded. A later AD replaced this one: AD 99-21-07. Comply with the one in force.
This AD applies to McDonnell Douglas Corporation 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.
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 certain McDonnell Douglas Model DC-9 series airplanes, that requires either replacement or modification of the hydraulic damper assembly. This amendment is prompted by reports indicating that insufficient damping of the hydraulic shimmy damper in the main landing gear (MLG) can allow high torsional vibration to occur. The actions specified by this AD are intended to prevent such vibration, which can damage the MLG assembly and lead to its collapse.
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.
