Airworthiness Directives; Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Airplanes

We are superseding Airworthiness Directive (AD) 2011-09-03 for all Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Model 382, 382B, 382E, 382F, and 382G airplanes. AD 2011-09-03 required repetitive eddy current inspections to detect cracks in the center wing upper and lower rainbow fittings, and corrective actions if necessary; and repetitive replacement of rainbow fittings, which would extend the repetitive interval for the next inspection. This new AD requires reduced intervals for inspections of the upper rainbow fittings. This AD was prompted by analysis of in-service cracking, which has shown that a reduction in the inspection intervals is necessary for the upper rainbow fittings. We are issuing this AD to detect and correct fatigue cracking of the upper and lower rainbow fittings on the center wings, which could grow large and lead to the failure of the fitting and a catastrophic failure of the center wing.