# Proposed AD FAA-2022-0465: Leonardo S.p.a. Helicopters

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2022-27-03
- Products: Leonardo
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM).
- Published: April 20, 2022, 87 FR 23477
- Comments due: June 6, 2022
- Became: [AD 2022-27-03](https://openairdocs.org/ad/2022-27-03)
- Docket: FAA-2022-0465 (https://www.regulations.gov/docket/FAA-2022-0465, where comments are filed)
- Project: AD-2022-00330-R
- FR document: 2022-08304
- Official PDF: https://openairdocs.org/files/sha256/9a/c8/9ac8a6668f172411b0c81d7ac123616c91a511a512b0f4241c99bc3d14661389 (from https://www.govinfo.gov/content/pkg/FR-2022-04-20/pdf/2022-08304.pdf)
- Federal Register: https://www.federalregister.gov/documents/2022/04/20/2022-08304/airworthiness-directives-leonardo-spa-helicopters
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/FR-ADNPRM-2022-08304-00000000000.0001
- Page: https://openairdocs.org/proposed/FAA-2022-0465

## Summary

The FAA proposes to supersede Airworthiness Directive (AD) 2021-20-10, which applies to certain Leonardo S.p.a. Model AB139 and AW139 helicopters. AD 2021-20-10 requires removing from service a certain part-numbered main gearbox (MGB) spherical bearing lock nut (lock nut) that is installed on certain part-numbered MGBs and replacing it with a newly designed MGB lock nut. AD 2021-20-10 also prohibits installing any MGB with the affected MGB lock nut and prohibits installing any affected MGB lock nut on any helicopter. Since the FAA issued AD 2021-20-10, it was discovered that a part number (P/ N) was incorrectly listed and that the applicability needed to be clarified. This proposed AD would retain the requirements of AD 2021- 20-10 and would clarify the applicability. The FAA is proposing this AD to address the unsafe condition on these products.

## Notices in this docket

- Apr 20, 2022: Notice of proposed rulemaking (NPRM). (first notice), FR document 2022-08304, comments due Jun 6, 2022 (https://www.federalregister.gov/documents/2022/04/20/2022-08304/airworthiness-directives-leonardo-spa-helicopters)

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