# Proposed AD 96-NM-137-AD: Construcciones Aeronauticas, S.A. (CASA) Model CN-235 Series Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 97-21-06
- Action: Notice of proposed rulemaking (NPRM).
- Published: February 7, 1997, 62 FR 5785
- Comments due: March 20, 1997
- Became: [AD 97-21-06](https://openairdocs.org/ad/97-21-06)
- Docket: 96-NM-137-AD
- FR document: 97-3028
- Official PDF: https://openairdocs.org/files/sha256/af/c9/afc9ae1bd2d195fa75d5d6e24163a127e16d5d840f0eadc7a9725df100c72ec4 (from https://www.govinfo.gov/content/pkg/FR-1997-02-07/pdf/97-3028.pdf)
- Federal Register: https://www.federalregister.gov/documents/1997/02/07/97-3028/airworthiness-directives-construcciones-aeronauticas-sa-casa-model-cn-235-series-airplanes
- Page: https://openairdocs.org/proposed/96-NM-137-AD

## Summary

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain CASA Model CN-235 series airplanes. This proposal would require repetitive inspections of the torsion tubes and fittings of the elevator and rudder assemblies to detect stress corrosion cracking, and replacement of cracked parts. This proposed action also would require the accomplishment of a modification that would constitute terminating action for the repetitive inspections. This proposal is prompted by reports indicating that stress corrosion cracking in these parts has been found on some airplanes. The actions specified by the proposed AD are intended to prevent loss of control of the elevator and/or rudder, due to failure of the elevator and/or rudder assemblies as a result of stress corrosion cracking.

## Notices in this docket

- Feb 7, 1997: Notice of proposed rulemaking (NPRM). (first notice), FR document 97-3028, comments due Mar 20, 1997 (https://www.federalregister.gov/documents/1997/02/07/97-3028/airworthiness-directives-construcciones-aeronauticas-sa-casa-model-cn-235-series-airplanes)

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