# Proposed AD 99-SW-39-AD: Eurocopter France Model AS-350B, BA, B1, B2, and D, and Model AS-355E, F, F1, F2, and N Helicopters

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2000-10-10
- Action: Notice of proposed rulemaking (NPRM).
- Published: February 11, 2000, 65 FR 6927
- Comments due: April 11, 2000
- Became: [AD 2000-10-10](https://openairdocs.org/ad/2000-10-10)
- Docket: 99-SW-39-AD
- FR document: 00-3225
- Official PDF: https://openairdocs.org/files/sha256/83/ca/83ca4a9ed0812c78bd4c6830baa20f67daecf150dc848d36fdf24f7c5972db60 (from https://www.govinfo.gov/content/pkg/FR-2000-02-11/pdf/00-3225.pdf)
- Federal Register: https://www.federalregister.gov/documents/2000/02/11/00-3225/airworthiness-directives-eurocopter-france-model-as-350b-ba-b1-b2-and-d-and-model-as-355e-f-f1-f2
- Page: https://openairdocs.org/proposed/99-SW-39-AD

## Summary

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to Eurocopter France Model AS- 350B, BA, B1, B2, and D, and Model AS-355E, F, F1, F2, and N helicopters, that currently requires inspecting the main gearbox suspension bi-directional cross-beam (cross-beam) for cracks, and replacing the cross-beam if a crack is found. This action would require the same inspections as the existing AD but would add the time intervals for performing repetitive dye-penetrant inspections on cross- beams with 5,000 or more hours time-in-service (TIS). This proposal is prompted by the discovery that time intervals for performing the required dye-penetrant inspections are not included in the existing AD. The actions specified by the proposed AD are intended to prevent failure of the cross-beam that could cause the main gearbox to pivot resulting in severe vibrations and a subsequent forced landing.

## Notices in this docket

- Feb 11, 2000: Notice of proposed rulemaking (NPRM). (first notice), FR document 00-3225, comments due Apr 11, 2000 (https://www.federalregister.gov/documents/2000/02/11/00-3225/airworthiness-directives-eurocopter-france-model-as-350b-ba-b1-b2-and-d-and-model-as-355e-f-f1-f2)

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