Airworthiness Directives; McDonnell Douglas Model DC-9-80 Series Airplanes and Model MD-88 Airplanes

This amendment supersedes an existing airworthiness directive (AD), applicable to all McDonnell Douglas Model DC-9-80 series airplanes and Model MD-88 airplanes, that currently requires revisions to the Airplane Flight Manual (AFM) and installation of inspection aids on the wing upper surfaces. This amendment requires, 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 is prompted by incidents in which ice accumulation on the wing upper surfaces shed into the engines during takeoff. The actions specified by this AD are intended to prevent ice accumulation on the wing upper surfaces, which could result in ingestion of ice into one or both engines and consequent loss of thrust from one or both engines.