Airworthiness Directives; McDonnell Douglas Model 717-200 Airplanes
The FAA is adopting a new airworthiness directive (AD) for certain McDonnell Douglas Model 717-200 airplanes. This AD requires replacing certain attaching hardware of the bulkhead nipple assemblies of the left and right wing vent boxes with new electrical bonding attaching hardware, doing resistance testing of the new electrical bonds, and doing fuel leakage testing of the reworked nipple assemblies. This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to provide a conductive path, from the bulkhead nipple assemblies of the left and right wing vent boxes to the airframe structure inside the wing fuel tanks, to dissipate high- amperage lightning-induced currents, which might otherwise create an ignition source for fuel vapors inside the wing vent boxes and lead to an explosion of the fuel tanks.