Airworthiness Directives; McDonnell Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 Airplanes

This amendment supersedes an existing airworthiness directive (AD), applicable to all McDonnell Douglas Model DC-9-81 (MD-81), DC-9- 82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 airplanes, that currently requires revisions to the Airplane Flight Manual; installation of inspection aids on the wing upper surfaces; and, among other actions, installation of an overwing heater blanket system or primary upper wing ice detection system, and installation of a heater protection panel or an equipment protection device on certain overwing heater blanket systems. This amendment retains those requirements and adds a requirement to disable the anti-ice systems for the upper wing surface on certain airplanes. The actions specified in this AD are intended to prevent ingestion of ice into one or both engines and consequent loss of thrust from one or both engines; and damage to the upper wing skin surface and its structure, due to prolonged short- circuit electrical arcing of certain anti-ice systems.