Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 747-400 and -400F series airplanes. This proposed AD would require a detailed inspection(s) for cracks and fractures of the side guide support fittings in the lower lobe cargo compartments; and applicable investigative/corrective actions and operational limitations, if necessary. This proposed AD also would require a terminating action for the repetitive inspections. This proposed AD is prompted by reports of cracked/fractured side guide support fittings in the aft, lower lobe cargo compartment. We are proposing this AD to prevent cracked/fractured side guide support fittings in the lower lobe cargo compartments, which could result in unrestrained cargo shifting in flight and damaging the airplane structure or systems, and consequent reduced controllability of the airplane.