Airworthiness Directives; Boeing Model 747-200, -300, and -400 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747-200, -300, and -400 series airplanes, that requires replacement of fuse pins in the upper link, midspar fittings, and diagonal brace of the nacelle strut with new corrosion-resistant pins. This amendment is prompted by reports of cracked fuse pins in the upper link, midspar fittings, and diagonal brace of the nacelle strut due to fatigue and corrosion. The actions specified by this AD are intended to prevent cracking or corrosion of the fuse pins of the nacelle strut, which could result in failure of the fuse pin and strut-to-wing attachment, and consequent loss of the strut and separation of the engine from the airplane.