Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 747-400, 747-400D, and 747-400F series airplanes. This proposed AD would require repetitive detailed inspections for damage (degraded finish; missing, lifted, peeling, or blistering paint; or signs of corrosion) of the interior skin in the forward and aft cargo compartments, and corrective actions if necessary. This proposed AD is prompted by reports of skin corrosion on four Boeing Model 747 series airplanes that were delivered between 1995 and 1999. We are proposing this AD to detect and correct corrosion, which can penetrate the thickness of the skin and cause cracking, and result in rapid decompression of the airplane.