Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model MD-90-30 series airplanes. This proposal would require repetitive fluorescent penetrant and magnetic particle inspections to detect fatigue cracking of the main landing gear (MLG) piston, and repair, if necessary. This proposal is prompted by reports of MLG failures during towing of in-service airplanes due to fatigue cracks. The actions specified by the proposed AD are intended to detect and correct fatigue cracking of MLG pistons, which could result in failure of the pistons, and consequent damage to the airplane structure and injury to flight crew, passengers, or ground personnel.