Airworthiness Directives; The Boeing Company Airplanes

摘要

We propose to supersede airworthiness directive (AD) 89-12-10, which applies to certain The Boeing Company Model 747 series airplanes. AD 89-12-10 currently requires replacement of certain underwing fuel tank access doors with stronger, fire-resistant doors. Since we issued AD 89-12-10, we have received reports indicating that a standard access door was located where an impact-resistant access door was required, and stencils were missing from some impact-resistant access doors. Stencils are required to indicate that the door is impact-resistant and to indicate the correct location for installation of the impact- resistant door. This proposed AD would require an inspection of the left- and right-hand wing fuel tank access doors to determine whether impact-resistant access doors are installed in the correct locations, and replacement of any door with an impact-resistant access door if necessary. This proposed AD would also require an inspection for the presence of stencils and index markers on impact-resistant access doors, and application of new stencils or index markers if necessary. This proposed AD would also require revising the maintenance program to incorporate changes to the