# Airworthiness Directives; Westland Helicopters Ltd. 30 Series 100 and 100-60 Helicopters
> **Rule** · Final rule; request for comments. · Published 1998-12-30 · Effective 1999-01-14 · 63 FR 71741
## Document
- **Document number:** 98-34502
- **Category:** airworthiness
- **Manufacturer:** Westland
- **Type:** Rule
- **Action:** Final rule; request for comments.
- **Citation:** 63 FR 71741
- **Publication date:** 1998-12-30
- **Effective date:** 1999-01-14
- **FAA docket:** Docket No. 97-SW-40-AD
## Abstract

This amendment adopts a new airworthiness directive (AD) that is applicable to Westland Helicopters Ltd. (Westland) 30 Series 100 and 100-60 helicopters. This action requires the removal and replacement of conformal pinion quill shafts installed in certain main rotor gearboxes that fail to pass a magnetic drain plug inspection. This amendment is prompted by a report of a forced landing that occurred when a single conformal pinion quill shaft failed in a main rotor gearbox (MRGB). This condition, if not corrected, could result in the failure of a MRGB, and a subsequent forced landing or loss of control of the helicopter.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1998/12/30/98-34502/airworthiness-directives-westland-helicopters-ltd-30-series-100-and-100-60-helicopters)
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