Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model 717-200 airplanes. This proposal would require modification of the longeron-to-frame installation of the upper center fuselage. This action is necessary to prevent fatigue cracking of the longerons of the upper center fuselage, which could result in reduced structural integrity of the fuselage. This action is intended to address the identified unsafe condition.