# Proposed AD 99-NM-48-AD: Airbus Industrie Model A320 Series Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 99-20-06
- Action: Notice of proposed rulemaking (NPRM).
- Published: June 28, 1999, 64 FR 34588
- Comments due: July 28, 1999
- Became: [AD 99-20-06](https://openairdocs.org/ad/99-20-06)
- Docket: 99-NM-48-AD
- FR document: 99-16328
- Official PDF: https://openairdocs.org/files/sha256/57/d8/57d81a1403bc30c0df12a25b6d5616c7e7b09e0bdb71a4a8777cdf0d1a6bd7c4 (from https://www.govinfo.gov/content/pkg/FR-1999-06-28/pdf/99-16328.pdf)
- Federal Register: https://www.federalregister.gov/documents/1999/06/28/99-16328/airworthiness-directives-airbus-industrie-model-a320-series-airplanes
- Page: https://openairdocs.org/proposed/99-NM-48-AD

## Summary

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Airbus Industrie Model A320 series airplanes. This proposal would require 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 proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed 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.

## Notices in this docket

- Jun 28, 1999: Notice of proposed rulemaking (NPRM). (first notice), FR document 99-16328, comments due Jul 28, 1999 (https://www.federalregister.gov/documents/1999/06/28/99-16328/airworthiness-directives-airbus-industrie-model-a320-series-airplanes)

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