# Proposed AD FAA-2018-0216: Honeywell International Inc. Turboprop Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2018-22-01
- Products: Honeywell International
- Product type: Engine
- Action: Notice of proposed rulemaking (NPRM).
- Published: June 20, 2018, 83 FR 28550
- Comments due: August 6, 2018
- Became: [AD 2018-22-01](https://openairdocs.org/ad/2018-22-01)
- Docket: FAA-2018-0216 (https://www.regulations.gov/docket/FAA-2018-0216, where comments are filed)
- FR document: 2018-13211
- Official PDF: https://openairdocs.org/files/sha256/67/e3/67e35a1b42a75720dff872027ac02cef62e0eb85da5cecdabd65b4989d0cc06f (from https://www.govinfo.gov/content/pkg/FR-2018-06-20/pdf/2018-13211.pdf)
- Federal Register: https://www.federalregister.gov/documents/2018/06/20/2018-13211/airworthiness-directives-honeywell-international-inc-turboprop-engines
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/A2BF3C23BD3D33D4862582B200545B47.0001
- Page: https://openairdocs.org/proposed/FAA-2018-0216

## Summary

We propose to supersede Airworthiness Directive (AD) 88-12-10, which applies to certain Honeywell International Inc. (Honeywell) TPE331 turboprop engines. AD 88-12-10 requires reducing the life limit for certain second stage turbine rotors. Since we issued AD 88-12-10, we received a report that a TPE331-11U engine experienced an uncontained rotor separation. In addition, cracks were discovered through eddy current inspection (ECI) in the bore of the second stage turbine rotor assembly after publication of AD 88-12-10. This proposed AD would require removing certain second stage turbine rotors from service at a reduced life limit. We are proposing this AD to address the unsafe condition on these products.

## Notices in this docket

- Jun 20, 2018: Notice of proposed rulemaking (NPRM). (first notice), FR document 2018-13211, comments due Aug 6, 2018 (https://www.federalregister.gov/documents/2018/06/20/2018-13211/airworthiness-directives-honeywell-international-inc-turboprop-engines)

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