Airworthiness Directives; McDonnell Douglas Model MD-90-30 Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model MD-90-30 airplanes, that requires measuring the length of the wear indicator on the brake stack of the main landing gear (MLG) brake assembly to determine the degree of wear, and follow-on actions. This action also requires eventual replacement of the existing MLG brake assembly with a new, improved or modified assembly, which constitutes terminating action for any repetitive actions being performed per this AD. The actions specified by this AD are intended to prevent failure of the MLG brakes and consequent loss of braking capability, which could result in the airplane overrunning the runway during take-off or landing. This action is intended to address the identified unsafe condition.