Summary
We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 787-8 airplanes. This proposed AD was prompted by reports indicating that certain wing side-of-body stringer fittings have been installed with faying surface mismatch beyond the allowed machining tolerance. This proposed AD would require inspection of certain stringer fittings for faying surface mismatch common to the side-of-body rib chord, replacement if necessary, and replacement of the clearance fit fasteners common to the side-of-body fittings and upper side-of-body rib chord with tapered sleeve bolts. We are proposing this AD to prevent an unacceptable reduction of the fatigue life in the upper side-of-body rib chord. Associated fatigue cracks can reduce the structural capability to a point where it cannot sustain limit load, which could adversely affect the structural integrity of the airplane.