Airworthiness Directives; GE Aviation Czech s.r.o. (Type Certificate Previously Held by WALTER Engines a.s., Walter a.s., and MOTORLET a.s.) Turboprop Engines

The FAA is adopting a new airworthiness directive (AD) for all GE Aviation Czech s.r.o. (GEAC) M601D-11, M601E-11, M601E-11A, M601E- 11AS, M601E-11S, and M601F model turboprop engines. This AD was prompted by the manufacturer finding errors in the Airworthiness Limitation Section (ALS) of the Engine Maintenance Manual (EMM), including errors in the formula to determine the equivalent flight cycles (FCs) of critical parts and errors with certain part numbers (P/ Ns). The manufacturer also determined that the life limit of a certain compressor case is not listed in the ALS section of the applicable EMM. This AD requires recalculating the life of critical parts and, depending on the results of the recalculation, replacement of these critical parts. This AD also requires replacement of a certain compressor case. The FAA is issuing this AD to address the unsafe condition on these products.