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 a report of fuel leaking onto the hot exhaust portion of an engine as a result of an un-intended leak path from the leading edge through the pylons. This proposed AD would require installing new seal dams in the inboard and outboard corners of the aft pylon frame on the left and right engines, including an inspection for damage of the outboard blade seal and applicable corrective actions. We are proposing this AD to prevent fuel leaking from an unintended drain path from the leading edge through the pylons and onto the hot engine parts or brakes, which could lead to a major ground fire.