# Airworthiness Directives; Boeing Vertol (Type Certificate Currently Held by Columbia Helicopters, Inc. (CHI)) and Kawasaki Heavy Industries, Limited Helicopters (Kawasaki)
> **Rule** · Final rule; request for comments. · Published 2012-07-23 · Effective 2012-08-07 · 77 FR 42954
## Document
- **Document number:** 2012-17278
- **Category:** airworthiness
- **Manufacturer:** Boeing Vertol (Type Certificate Currently Held by Columbia
- **Type:** Rule
- **Action:** Final rule; request for comments.
- **Citation:** 77 FR 42954
- **Publication date:** 2012-07-23
- **Effective date:** 2012-08-07
- **FAA docket:** Docket No. FAA-2012-0730
## Abstract

We are adopting a new airworthiness directive (AD) for CHI Model 107-II and Kawasaki Model KV107-II and KV107-IIA helicopters. This AD requires, before further flight, replacing certain upper collective pitch control yoke bolts. This AD is prompted by three failures of the affected bolts. These actions are intended to prevent failure of an upper collective pitch control yoke bolt (bolt), excessive vibration, migration of the shafts, and subsequent loss of control of the helicopter.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2012/07/23/2012-17278/airworthiness-directives-boeing-vertol-type-certificate-currently-held-by-columbia-helicopters-inc)
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