Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 747-400 series airplanes. This proposed AD was prompted by reports of potable water leaking into the electrical equipment bay cooling air inlet. This proposed AD would require performing repetitive inspections of potential water sources from the upper deck and the main deck, including potable water and waste water lines, for any water leaks and clogs, and applicable on- condition actions. The FAA is proposing this AD to address the unsafe condition on these products.