Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model DC-9-81, -82, -83, and -87 series airplanes; Model MD-88 airplanes; and Model MD-90-30 series airplanes. This proposal would require replacement of certain main landing gear (MLG) shock strut piston assemblies with new or serviceable, improved assemblies, which would constitute terminating action for the requirements of certain other ADs. This action is necessary to prevent fatigue cracking of the MLG shock strut pistons, which could result in failure of the MLG shock strut pistons during landing or jacking of the airplane, and consequent damage to the airplane structure and injury to the passengers, flightcrew, or ground personnel. This action is intended to address the identified unsafe condition.