# Proposed AD FAA-2020-0920: Sikorsky Aircraft and Sikorsky Aircraft Corporation Helicopters

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2021-05-19
- Products: Sikorsky
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: October 26, 2020, 85 FR 67692
- Comments due: December 10, 2020
- Became: [AD 2021-05-19](https://openairdocs.org/ad/2021-05-19)
- Docket: FAA-2020-0920 (https://www.regulations.gov/docket/FAA-2020-0920, where comments are filed)
- Project: AD-2020-00662-R
- FR document: 2020-23466
- Official PDF: https://openairdocs.org/files/sha256/47/bd/47bd61d48682db4d7cc0c7b46d2d0a1ba5099a62db4121854f209344bb618aff (from https://www.govinfo.gov/content/pkg/FR-2020-10-26/pdf/2020-23466.pdf)
- Federal Register: https://www.federalregister.gov/documents/2020/10/26/2020-23466/airworthiness-directives-sikorsky-aircraft-and-sikorsky-aircraft-corporation-helicopters
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/B408F11D3CEF44108625860D0046B11E.0001
- Page: https://openairdocs.org/proposed/FAA-2020-0920

## Summary

The FAA proposes to adopt a new airworthiness directive (AD) for all Sikorsky Aircraft Model S-61L, S-61N, S-61NM, and S-61R helicopters and Sikorsky Aircraft Corporation Model S-61A, S-61D, S- 61E, and S-61V restricted category helicopters. This proposed AD was prompted by the manufacturer determining that there may be arm assemblies in service that have accumulated 15,000 or more hours time- in-service (TIS), which exceeds the service life limit for this component. This proposed AD would require reviewing the mixer unit component log card or equivalent record and, depending on the number of hours TIS, calculating the remaining life of the arm assembly or removing the arm assembly from service. The FAA is proposing this AD to address the unsafe condition on these products.

## Notices in this docket

- Oct 26, 2020: Notice of proposed rulemaking (NPRM). (first notice), FR document 2020-23466, comments due Dec 10, 2020 (https://www.federalregister.gov/documents/2020/10/26/2020-23466/airworthiness-directives-sikorsky-aircraft-and-sikorsky-aircraft-corporation-helicopters)

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