AD FAA-2011-1419

We are superseding an existing airworthiness directive (AD) for certain The Boeing Company Model 737-300, -400, and -500 series airplanes. That AD currently requires repetitive inspections for cracking of the crown area of the fuselage skin, and corrective actions if necessary. This new AD adds repetitive inspections for cracking using different inspection methods and inspecting additional areas, and corrective actions if necessary. This new AD also requires additional repairs to previously repaired areas and repetitive inspections for loose fasteners and replacement if necessary in certain previously repaired areas. This AD also reduces certain compliance times and extends certain other compliance times. This AD was prompted by additional reports of cracking at the horizontal chem-mill steps away from the lap joints over the entire crown area, and vertical chem-mill cracks adjacent to the butt joints. We are issuing this AD to detect and correct fatigue cracking of the fuselage skin, which could cause the fuselage skin to fracture and fail, and result in rapid decompression of the airplane.