Summary
We propose to adopt a new airworthiness directive (AD) for certain Airbus Model A300 F4-600R series airplanes. This proposed AD was prompted by a report of two adjacent frame forks that were found cracked on the aft lower deck cargo door (LDCD) of two Model A300-600F4 airplanes during scheduled maintenance. This proposed AD would require repetitive high frequency eddy current (HFEC) inspections of the aft LDCD frame forks; a one-time check of the LDCD clearances; and a one- time detailed visual inspection of hooks, eccentric bushes, and x- stops; and corrective actions if necessary. We are proposing this AD to detect and correct cracked or ruptured aft LDCD frames, which could allow loads to be transferred to the remaining structural elements. This condition could lead to the rupture of one or more vertical aft LDCD frames, which could result in reduced structural integrity of the aft LDCD.