# Airworthiness Directives; Airbus Helicopters
> **Rule** · Final rule. · Published 2021-03-10 · Effective 2021-04-14 · 86 FR 13633
## Document
- **Document number:** 2021-04806
- **Category:** airworthiness
- **Manufacturer:** Airbus
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 86 FR 13633
- **Publication date:** 2021-03-10
- **Effective date:** 2021-04-14
- **FAA docket:** Docket No. FAA-2020-0847
## Abstract

The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, and AS350D helicopters; Model AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters; and Model EC130 B4 and EC130 T2 helicopters. This AD requires a one-time inspection to verify the presence and correct installation of the main rotor mast (MRM) upper bearing retaining rings, a repetitive inspection of the sealant bead on the MRM for damage, and corrective actions if necessary. This AD was prompted by a report of a missing retaining ring of the inner race of the MRM upper bearing. The actions of this AD are intended to address an unsafe condition on these products.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2021/03/10/2021-04806/airworthiness-directives-airbus-helicopters)
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