# Airworthiness Directives; Airbus Industrie Model A320 Series Airplanes
> **Rule** · Final rule. · Published 1999-09-24 · Effective 1999-10-29 · 64 FR 51686
## Document
- **Document number:** 99-24846
- **Category:** airworthiness
- **Manufacturer:** Airbus Industrie Model A320 Series
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 64 FR 51686
- **Publication date:** 1999-09-24
- **Effective date:** 1999-10-29
- **FAA docket:** Docket No. 99-NM-48-AD
## Abstract

This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Industrie Model A320 series airplanes, that requires replacement of the disc valve and spring in the low pressure non-return valve of the airborne ground check module (AGCM) of the ram air turbine (RAT). This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent malfunction of the low pressure non-return valve in the AGCM. If the RAT is being used due to the loss of other systems, a malfunction of the valve could result in loss of the blue hydraulic system, and consequent loss of certain flight control and electrical systems of the airplane.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1999/09/24/99-24846/airworthiness-directives-airbus-industrie-model-a320-series-airplanes)
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