Airworthiness Directives; The Boeing Company Airplanes

We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 727 airplanes. This AD was prompted by a report of cracking in the inboard lower flange and adjacent web near the forward attachment of the outboard flap track at a certain position on a Model 737-300 airplane. The flap tracks of Model 737-300 airplanes are similar to the flap tracks of Model 727 airplanes. This AD requires repetitive detailed inspections and surface high frequency eddy current (HFEC) inspections of each outboard flap track at certain positions for any crack and discrepancy, and applicable on-condition actions. We are issuing this AD to address the unsafe condition on these products.