Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 737 series airplanes. This proposal would require initial and repetitive inspections of certain areas of the wing spars to detect cracking or corrosion; and follow-on corrective actions and repair, if necessary. This proposal is prompted by reports of cracks and corrosion in the upper chord of the front and rear spars of the wing and reports of cracks propagating from previously repaired areas. The actions specified in the proposed AD are intended to detect and correct such cracking or corrosion of the upper and lower chords of the wing spars, which could result in reduced structural integrity of the wing.