Airworthiness Directives; The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP Series Airplanes

요약

We propose to supersede an existing airworthiness directive (AD) that applies to the products listed above. The existing AD currently requires an inspection of the No. 2 and No. 3 windows on the left and right sides of the airplane to determine their part numbers, related investigative and corrective actions if necessary, and repetitive inspections of single pane windows. Since we issued that AD, we have determined that terminating action for the repetitive inspections is necessary. This proposed AD would add a requirement to install dual pane No. 2 and No. 3 windows. This proposed AD also removes certain airplanes from the applicability. We are proposing this AD to detect and correct cracking in the fail-safe interlayer of certain No. 2 and No. 3 glass windows, which could result in loss of the window and consequent rapid loss of cabin pressure. Loss of the window could also result in crew communication difficulties or incapacitation of the crew.