After the discovery of cracks in the front spar shear tie and at the intercostal lug fitting on some 747 aircraft, the Federal Aviation Administration adopted a new airworthiness directive (AD) that affects all 747-200Fs and 747-400Fs on U.S. Air Operator Certificates. Although ADs are routinely issued, the current unavailability of repair kits and a fast-approaching effective date of Oct. […]