# Proposed AD 99-NM-117-AD: Construcciones Aeronauticas, S.A. (CASA), Model CN-235 Series Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 99-22-06
- Action: Notice of proposed rulemaking (NPRM).
- Published: August 12, 1999, 64 FR 43953
- Comments due: September 13, 1999
- Became: [AD 99-22-06](https://openairdocs.org/ad/99-22-06)
- Docket: 99-NM-117-AD
- FR document: 99-20893
- Official PDF: https://openairdocs.org/files/sha256/0d/48/0d489c83541aee6bd0f3146de53e23cf22f222f467c7907e0f6b3df9a22f0613 (from https://www.govinfo.gov/content/pkg/FR-1999-08-12/pdf/99-20893.pdf)
- Federal Register: https://www.federalregister.gov/documents/1999/08/12/99-20893/airworthiness-directives-construcciones-aeronauticas-sa-casa-model-cn-235-series-airplanes
- Page: https://openairdocs.org/proposed/99-NM-117-AD

## Summary

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to all CASA Model CN-235 series airplanes, that currently requires repetitive eddy current inspections to detect fatigue cracks in the nose landing gear (NLG) turning tube, and replacement of cracked tubes. This proposal would add a requirement for the replacement of the existing NLG turning tube constructed of aluminum alloy with a new NLG turning tube made of steel; such replacement would terminate the repetitive inspections. 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 fatigue cracking and failure of the NLG turning tube, which could result in reduced structural integrity of the NLG.

## Notices in this docket

- Aug 12, 1999: Notice of proposed rulemaking (NPRM). (first notice), FR document 99-20893, comments due Sep 13, 1999 (https://www.federalregister.gov/documents/1999/08/12/99-20893/airworthiness-directives-construcciones-aeronauticas-sa-casa-model-cn-235-series-airplanes)

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.