Summary
We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 777 airplanes. This proposed AD was prompted by reports that escape slides/rafts did not deploy due to galvanic corrosion of the door-mounted slide/raft packboard release mechanisms. This proposed AD would require doing a general visual inspection of the housing assembly of the packboard release mechanism to determine if its surface treatment has been sealed, and if unsealed, replacing the housing assembly with a new or serviceable housing assembly. We are proposing this AD to detect and correct corrosion of the packboard release mechanisms, which could interfere with escape slide/raft deployment, prohibit doors from opening in the armed mode, and cause consequent delay and injury during evacuation of passengers and crew from the cabin in the event of an emergency.