Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all McDonnell Douglas Model MD-90-30 airplanes. This proposal would require replacing the lanyards on the pressure relief door for the thrust reverser with new, improved lanyards, and doing associated modifications. This action is necessary to ensure that the lanyards on the pressure relief door have adequate strength. Lanyards of inadequate strength could allow the pressure relief door to detach from the thrust reverser in the event that an engine bleed air duct bursts, which could result in the detached door striking and damaging the horizontal stabilizer, and consequent reduced controllability of the airplane. This action is intended to address the identified unsafe condition.