Transportation Department, Federal Aviation Administration
The FAA proposes to adopt a new airworthiness directive (AD) for certain Leonardo S.p.a. (Leonardo) Model AB139 and AW139 helicopters. This proposed AD was prompted by a report of several occurrences of a cracked main gearbox (MGB) spherical bearing lock nut (lock nut). This proposed AD would require removing from service a certain part-numbered MGB lock nut that is installed on certain part- numbered MGBs and replacing it with newly designed MGB lock nut. This proposed AD would also would prohibit installing any MGB with the affected MGB lock nut and would prohibit installing any affected MGB lock nut on any helicopter. 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-2021-0579; Project Identifier MCAI-2020-00267-R] RIN 2120-AA64 AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) for certain Leonardo S.p.a. (Leonardo) Model AB139 and AW139 helicopters. This proposed AD was prompted by a report of several occurrences of a cracked main gearbox (MGB) spherical bearing lock nut (lock nut). This proposed AD would require removing from service a certain part-numbered MGB lock nut that is installed on certain part-numbered MGBs and replacing it with newly designed MGB lock nut. This proposed AD would also would prohibit installing any MGB with the affected MGB lock nut and would prohibit installing any affected MGB lock nut on any helicopter. 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 September 9, 2021. ADDRESSES: You may send comments by any of the following methods: Federal eRulemaking Docket: Go to https://www.regulations.gov . Follow the online instructions for sending your comments electronically. Fax : (202) 493-2251. Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590-0001. Hand Delivery: Deliver to the Mail address between 9 a.m. and 5 …
Other Federal Register documents from the same docket.
Citation: 86 FR 39984
