Airworthiness Directives; Cessna Aircraft Company Models 172R and 172S Airplanes

This amendment adopts a new airworthiness directive (AD) that applies to certain Cessna Aircraft Company (Cessna) Models 172R and 172S airplanes. This AD requires a one-time inspection for proper engine idle speed and fuel control mixture setting and adjustment, as necessary. This AD also requires incorporating engine operating procedures into the pilots operating handbook (POH) and FAA-approved airplane flight manual (AFM). This AD is the result of reports of rough engine operation because of an over-rich fuel mixture (improper fuel flow settings). The actions specified by this AD are intended to detect and correct such improper fuel flow settings, which could result in rough engine operation or engine stoppage. This over-rich fuel mixture also contributes to the engine not restarting during flight when using published in-flight restart procedures.