# Airworthiness Directives; The Boeing Company Airplanes
> **Rule** · Final rule. · Published 2020-09-03 · Effective 2020-10-08 · 85 FR 54885
## Document
- **Document number:** 2020-19387
- **Category:** airworthiness
- **Manufacturer:** The Boeing Company
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 85 FR 54885
- **Publication date:** 2020-09-03
- **Effective date:** 2020-10-08
- **FAA docket:** Docket No. FAA-2019-1070
## Abstract

The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 787-8 and 787-9 airplanes. This AD was prompted by reports that the cabin air compressor (CAC) outlet check valve failed due to fatigue of the aluminum flappers, and exposed the Y-duct to temperatures above its design limit. This AD requires installing new inboard and outboard CAC outlet check valves on the left-side and right-side cabin air conditioning and temperature control system (CACTCS) packs. The FAA is issuing this AD to address the unsafe condition on these products.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2020/09/03/2020-19387/airworthiness-directives-the-boeing-company-airplanes)
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