Airworthiness Directives; Boeing Model 747 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747 series airplanes, that requires repetitive detailed visual inspections to detect corrosion on the rear spar web of the wing center section and adjacent bulkhead fittings at body station 1241; and corrective action, if necessary. This amendment is prompted by reports of corrosion found on the rear spar web and bulkhead fitting. The actions specified by this AD are intended to detect and correct such corrosion, which could cause cracking of the rear spar web, and result in a fuel leak and consequent fire/explosion in the wheel well of the main landing gear.