AD 2005-13-05: Boeing Model 747-400F Series Airplanes

(c) This AD applies to Model 747-400F series airplanes, certificated in any category, as listed in Boeing Alert Service Bulletin 747-53A2443, dated May 9, 2002. Unsafe Condition (d) This AD was prompted by reports of fatigue cracking found on the upper deck floor beam to frame attachment points. We are issuing this AD to prevent fatigue cracks in the upper chord, upper chord strap, and web of the upper deck floor beams and the resultant failure of the floor beams. Failure of a floor beam could result in damage to critical flight control cables and wire bundles that pass through the floor beam, and consequent loss of controllability of the airplane. Failure of the floor beam also could result in the failure of the adjacent fuselage frames and skin, and consequent rapid decompression of the airplane.