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 cracks found in the rear spar web and lower chord on the left and right wings. This proposed AD would require repetitive detailed inspections for cracking of the rear spar web and lower chord, and applicable on- condition actions. We are proposing this AD to address the unsafe condition on these products.