# Proposed AD 93-SW-20-AD: Bell Helicopter Textron, Inc. Model 214B, 214B-1, and 214ST Helicopters

- Type: Proposed airworthiness directive (not in force)
- Status: Comment period closed
- Action: Notice of proposed rulemaking (NPRM).
- Published: January 5, 1994, 59 FR 556
- Comments due: February 22, 1994
- Docket: 93-SW-20-AD
- FR document: 94-143
- Federal Register: https://www.federalregister.gov/documents/1994/01/05/94-143/airworthiness-directives-bell-helicopter-textron-inc-model-214b-214b-1-and-214st-helicopters
- Page: https://openairdocs.org/proposed/93-SW-20-AD

## Summary

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to Bell Helicopter Textron, Inc. Model 214B, 214B-1, and 214ST helicopters. This proposal would establish a mandatory retirement life of 60,000 high-power events for the main rotor trunnion (trunnion), which is currently not a life- limited part. This proposal is prompted by the manufacturer's analysis and retesting that has shown that the trunnion is sensitive to high- power events. The actions specified by the proposed AD are intended to prevent fatigue failure of the trunnion, that could result in loss of the main rotor and subsequent loss of control of the helicopter.

## Notices in this docket

- Jan 5, 1994: Notice of proposed rulemaking (NPRM). (first notice), FR document 94-143, comments due Feb 22, 1994 (https://www.federalregister.gov/documents/1994/01/05/94-143/airworthiness-directives-bell-helicopter-textron-inc-model-214b-214b-1-and-214st-helicopters)

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