Airworthiness Directives; McDonnell Douglas Model 717-200 Airplanes

We are adopting a new airworthiness directive (AD) for certain McDonnell Douglas Model 717-200 airplanes. This AD requires installing an additional support bracket for the gray water drain hose; replacing the screw of the support bracket with a new screw for the potable water supply hose; installing a spacer; doing a detailed inspection to detect interference or wear damage on hoses, lines and/or cables; and doing corrective actions if necessary. This AD results from reports of interference between the potable water supply hose and/or gray water drain hose at the aft lavatories and the fuel line and/or power feeder cables of the auxiliary power unit (APU) located below the aft cabin floor. We are issuing this AD to prevent interference and chafing between the potable water supply hose and/or gray water hose and the fuel line and/or power feeder cables of the APU, which could cause arcing and sparking, and/or fuel leaking, and consequent fire.