Airworthiness Directives; Boeing Model 737-600, 737-700, 737-700C, 737-800, and 737-900 Series Airplanes

We are adopting a new airworthiness directive (AD) for certain Boeing Model 737-600, 737-700, 737-700C, 737-800, and 737-900 series airplanes. This AD requires an inspection of the vertical fin lugs, skin, and skin edges for discrepancies; an inspection of the flight control cables, fittings, and pulleys in section 48 for signs of corrosion; an inspection of the horizontal stabilizer jackscrew, ball nut, and gimbal pins for signs of corrosion; and corrective actions if necessary. This AD results from reports indicating that moisture was found within the section 48 cavity. We are issuing this AD to ensure that the correct amount of sealant was applied around the vertical fin lugs, skin and the skin edges. Missing sealant could result in icing of the elevator cables, which could cause a system jam and corrosion of structural and flight control parts, resulting in reduced controllability of the airplane.