# Airworthiness Directives; British Aerospace (Operations) Limited Model B.121 Series 1, 2, and 3 Airplanes
> **Rule** · Final rule. · Published 1998-12-18 · Effective 1999-01-29 · 63 FR 69999
## Document
- **Document number:** 98-33244
- **Category:** airworthiness
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 63 FR 69999
- **Publication date:** 1998-12-18
- **Effective date:** 1999-01-29
- **FAA docket:** Docket No. 97-CE-122-AD
## Abstract

This amendment adopts a new airworthiness directive (AD) that applies to all British Aerospace (Operations) Limited (British Aerospace) Model B.121 Series 1, 2, and 3 airplanes. This AD requires repetitively inspecting (using visual methods) the internal and external surfaces of the brake torque tube assemblies in the cockpit area for cracks. This AD also requires obtaining and incorporating repair procedures for any brake torque tube assembly found cracked. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for the United Kingdom. The actions specified by this AD are intended to detect and correct cracks in the brake torque tube assemblies, which could result in reduced brake efficiency with possible reduced and/or loss of airplane control.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1998/12/18/98-33244/airworthiness-directives-british-aerospace-operations-limited-model-b121-series-1-2-and-3-airplanes)
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