Transportation Department, Federal Aviation Administration
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.
Document Headings Document headings vary by document type but may contain the following: the agency or agencies that issued and signed a document the number of the CFR title and the number of each part the document amends, proposes to amend, or is directly related to the agency docket number / agency internal file number the RIN which identifies each regulatory action listed in the Unified Agenda of Federal Regulatory and Deregulatory Actions See the Document Drafting Handbook for more details. Department of Transportation Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2022-0465; Project Identifier AD-2022-00330-R] RIN 2120-AA64 AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). 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. DATES: The FAA must receive comments on this proposed AD by June 6, 2022. ADDRESSES: You may send comments, using the procedures found in 14 CFR 11.43 and 11.45 , by any of the following methods: Federal eRulemaking Portal: Go to https://www.regulations.gov . Follow the instructions for submitting comments. Fax : (202) 493-2251. Mail: U.S. Department of Transportation, Docket Oper…
Other Federal Register documents from the same docket.
Citation: 87 FR 23477
