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 upper aft skin at the rear spar of the wings. This proposed AD would require repetitive inspections for cracking of the upper aft skin of the wings, and repair if necessary. We are proposing this AD to address the unsafe condition on these products.