Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 747-100, 747-100B, 747-200B, 747-200C, 747- 200F, 747-300, 747SR, and 747SP series airplanes. This proposed AD would require repetitive high frequency eddy current inspections for cracks of the fuselage skin at stringer 5 left and right between stations 340 and 350, and corrective actions if necessary. This proposed AD results from reports of fatigue cracks in the fuselage skin near stringer 5 between stations 340 and 350. We are proposing this AD to detect and correct fatigue cracking of the fuselage skin near stringer 5. Cracks in this area could join together and result in in- flight depressurization of the airplane.