Summary
We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 787-8 airplanes. This proposed AD was prompted by reports of water leakage from the potable water system due to improperly installed waterline couplings, and water leaking into the electronics equipment (EE) bays from above the floor in the main cabin, resulting in water on the equipment in the EE bays. This proposed AD would require replacing the potable waterline couplings above the forward and aft EE bays with new, improved couplings. This proposed AD would also require sealing the main cabin floor areas above the aft EE bay, installing drip shields and foam blocks, and rerouting the wire bundles near the drip shields above the equipment in the aft EE bay. We are proposing this AD to prevent a water leak from an improperly installed potable water system coupling, or main cabin water source, which could cause the equipment in the EE bays to become wet, resulting in an electrical shortand potential loss of system functions essential for safe flight.