Summary
We propose to supersede Airworthiness Directive (AD) 98-13-23, which applies to certain Airbus Model A300 B4-600, B4-600R, and F4-600R series airplanes, and Model A300 C4-605R Variant F airplanes (collectively called Model A300-600 series airplanes). AD 98-13-23 requires inspections to detect corrosion and cracking of the lower horizontal stabilizer cutout longeron, the corner fitting, the skin strap, and the outer skin; and repair, if necessary. Since we issued AD 98-13-23, we have determined that the risk of cracking is higher than initially determined. This proposed AD would reduce the compliance times and repetitive intervals, and changes the inspection procedures. We are proposing this AD to prevent cracking of the lower horizontal stabilizer cutout longeron, the corner fitting, the skin strap, and the outer skin, which could result in reduced structural integrity of the horizontal-stabilizer cutout longeron.