Airworthiness Directives; Boeing Model 747-100, -200, -300, 747SR, and 747SP Series Airplanes

This document corrects information in an existing airworthiness directive (AD) that applies to certain Boeing Model 747- 100, -200, -300, 747SR, and 747SP series airplanes. That AD currently requires repetitive inspections to detect cracking of the longeron splice fittings at stringer 11, on the left and right sides at body station 2598, and replacement of any cracked fitting with a new fitting. This document clarifies the applicable compliance time for certain airplanes. This correction is necessary to ensure that fatigue cracking on longeron splice fittings, which could result in reduced controllability of the horizontal stabilizer, is detected and corrected in a timely manner.