Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 737-100, - 200, and -200C series airplanes. This proposal would require inspection of certain floor beams and transverse beams, and corrective actions, if necessary. The actions specified in the proposed AD are intended to detect and correct cracking at the aileron control quadrant cutouts and in the cabin floor beams and pressure web transverse beams above the main wheelwell, which could result in rapid loss of cabin pressure and reduced structural integrity of the airframe.