# Proposed AD FAA-2018-0739: Pratt & Whitney Canada Corp. Turboshaft Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2019-22-03
- Products: Pratt & Whitney Canada
- Product type: Engine
- Action: Notice of proposed rulemaking (NPRM).
- Published: September 17, 2018, 83 FR 46898
- Comments due: November 1, 2018
- Became: [AD 2019-22-03](https://openairdocs.org/ad/2019-22-03)
- Docket: FAA-2018-0739 (https://www.regulations.gov/docket/FAA-2018-0739, where comments are filed)
- FR document: 2018-19862
- Official PDF: https://openairdocs.org/files/sha256/1a/ac/1aacd740ffd14513d0f708cc59f02cfc9582b90431dcc5d039ebdab26c8d2e8e (from https://www.govinfo.gov/content/pkg/FR-2018-09-17/pdf/2018-19862.pdf)
- Federal Register: https://www.federalregister.gov/documents/2018/09/17/2018-19862/airworthiness-directives-pratt-and-whitney-canada-corp-turboshaft-engines
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/9886E5E3DF8201E38625830B00493EBF.0001
- Page: https://openairdocs.org/proposed/FAA-2018-0739

## Summary

We propose to supersede airworthiness directive (AD) 2015-20- 04, which applies to certain Pratt & Whitney Canada Corp. (P&WC) PT6B- 37A turboshaft engines. AD 2015-20-04 requires initial and repetitive inspections until replacement of the No. 10 bearing, and eventual replacement of the No. 9 bearing, both located in the engine reduction gearbox (RGB) assembly. Since we issued AD 2015-20-04, P&WC has determined that the repetitive inspection of the bearings has an associated risk of gearbox damage or contamination and that the bearing installation required by AD 2015-20-04 does not adequately address the issue of bearing axial movement. This proposed AD would require removal from service and replacement of the No. 9 and No. 10 position bearings. We are proposing this AD to address the unsafe condition on these products.

## Notices in this docket

- Sep 17, 2018: Notice of proposed rulemaking (NPRM). (first notice), FR document 2018-19862, comments due Nov 1, 2018 (https://www.federalregister.gov/documents/2018/09/17/2018-19862/airworthiness-directives-pratt-and-whitney-canada-corp-turboshaft-engines)

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