Summary
We propose to adopt a new airworthiness directive (AD) for all 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 webs of the stub beams at certain fuselage stations. These cracks are the result of fatigue caused by cyclical loading from pressurization, wing loads, and landing loads. This proposed AD would require repetitive inspections for cracking of the webs of the stub beams at certain fuselage stations, and applicable on-condition actions. We are proposing this AD to address the unsafe condition on these products.