Airworthiness Directive · Amendment 39-9989 · CFM International CFM56-3, -3B, and -3C Series Turbofan Engines
CFM International CFM56-3, -3B, and -3C Series Turbofan Engines
CFM International (CFMI) CFM56-3, -3B, and -3C series turbofan engines with fan disks, Part Number (P/N) 335-014- 509-0 or 335-014-511-0, installed, that are currently operating at, or have previously operated at, the Category C thrust rating. These engines are installed on but not limited to Boeing 737 series aircraft.
This amendment adopts a new airworthiness directive (AD), applicable to CFM International CFM56-3, -3B, -3C series turbofan engines, that requires a reduction of the low cycle fatigue (LCF) retirement lives for certain fan disks. This amendment is prompted by the results of a refined life analysis performed by the manufacturer which revealed minimum calculated LCF lives significantly lower than published LCF retirement lives. The actions specified by this AD are intended to prevent a LCF failure of the fan disk, which could result in an uncontained engine failure and damage to the aircraft.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
