AD NUMBER: 2006-05-08
SUBJECT: Airworthiness Directive 2006-05-08 SUMMARY: The FAA is
adopting a new airworthiness directive (AD) for certain Boeing
Model 777-200 series airplanes.
This AD requires installing a new washer between the lower wing
surface and the jam nut of the sump drain valve assembly. This AD
results from fuel system reviews conducted by the manufacturer.
We are issuing this AD to prevent energy from a lightning strike
on the bushing for the sump drain valve from arcing to the inside
of the center fuel tank wall, which could create an ignition source
in the fuel tank and result in a fuel tank explosion.