# Proposed AD FAA-2011-0946: CFM International, S. A. Model CFM56-5B Series Turbofan Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2012-02-03
- Products: CFM International
- Product type: Engine
- Action: Notice of proposed rulemaking (NPRM).
- Published: October 18, 2011, 76 FR 64293
- Comments due: December 2, 2011
- Became: [AD 2012-02-03](https://openairdocs.org/ad/2012-02-03)
- Docket: FAA-2011-0946 (https://www.regulations.gov/docket/FAA-2011-0946, where comments are filed)
- Project: 2011-NE-02-AD
- FR document: 2011-26823
- Official PDF: https://openairdocs.org/files/sha256/1f/ca/1fcaa5ae95fbc6d72c1ee55b03de945c44ac2b62b3ab140fb42561d4089e148e (from https://www.govinfo.gov/content/pkg/FR-2011-10-18/pdf/2011-26823.pdf)
- Federal Register: https://www.federalregister.gov/documents/2011/10/18/2011-26823/airworthiness-directives-cfm-international-s-a-model-cfm56-5b-series-turbofan-engines
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/6AEF6A718B6DFA4A8625792D0048726E.0001
- Page: https://openairdocs.org/proposed/FAA-2011-0946

## Summary

We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD would require removing from service certain serial number (S/N) fan blades, part number (P/N) 338- 002-114-0. This proposed AD was prompted by a normal quality sampling at CFM that isolated a production batch of fan blades with nonconforming geometry of mid-span shroud tips of the fan blades. This defect would cause the upper panel of the fan blade to be liberated following foreign object damage (FOD) or bird strike, and likely result in an inflight shutdown (IFSD). We are proposing this AD to prevent an IFSD of one or more engines following FOD or a bird strike.

## Notices in this docket

- Oct 18, 2011: Notice of proposed rulemaking (NPRM). (first notice), FR document 2011-26823, comments due Dec 2, 2011 (https://www.federalregister.gov/documents/2011/10/18/2011-26823/airworthiness-directives-cfm-international-s-a-model-cfm56-5b-series-turbofan-engines)

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