Airworthiness Directives; The Boeing Company Airplanes

We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 727 airplanes. This AD will complete certain mandated programs intended to support the airplane reaching its limit of validity (LOV) of the engineering data that support the established structural maintenance program. This AD requires repetitive inspections for cracking of small repairs done on the vertical flange of the rib chord, repetitive inspections for cracking along the upper fillet radius of the rib chord, and a large repair or preventive modification if necessary. Accomplishment of a large repair or preventive modification terminates the actions of this AD. We are issuing this AD to prevent cracks in the rib upper chord, which could result in the inability of the wing structure to support the limit load condition, and consequent loss of structural integrity of the wing.