Summary
We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This proposed AD was prompted by reports of cracking in the frame web, frame integral inboard chord, and fail-safe chord on multiple airplanes in multiple locations below the passenger floor, in addition to an evaluation by the design approval holder (DAH) indicating that certain fuselage frame splices are subject to widespread fatigue damage (WFD). This proposed AD would require repetitive inspections of certain fuselage upper frames, side frames, fail-safe chords, inboard chords, frame webs, and stringers; an inspection for the presence of repairs in certain inspections zones and open tooling holes; and applicable on-condition actions. We are proposing this AD to address the unsafe condition on these products.