# Airworthiness Directives; Sikorsky Aircraft Corporation Helicopters
> **Rule** · Final rule. · Published 2020-08-05 · Effective 2020-09-09 · 85 FR 47297
## Document
- **Document number:** 2020-16405
- **Category:** airworthiness
- **Manufacturer:** Sikorsky
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 85 FR 47297
- **Publication date:** 2020-08-05
- **Effective date:** 2020-09-09
- **FAA docket:** Docket No. FAA-2020-0212
## Abstract

The FAA is adopting a new airworthiness directive (AD) for certain Sikorsky Aircraft Corporation Model S-76C helicopters. This AD was prompted by reports of inaccurate main gear box (MGB) indications in flight. This AD requires updating the remote data acquisition unit (RDAU) software and re-identifying the RDAU and, for certain helicopters, updating the software of the display unit (DU) and re- identifying the DU. The FAA is issuing this AD to address the unsafe condition on these products.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2020/08/05/2020-16405/airworthiness-directives-sikorsky-aircraft-corporation-helicopters)
---
*AI Analytics · CC0 1.0*