# Airworthiness Directives; Textron Lycoming Model O-540-F1B5 Reciprocating Engines
> **Rule** · Final rule; request for comments. · Published 1999-02-03 · Effective 1999-02-18 · 64 FR 5149
## Document
- **Document number:** 99-2474
- **Category:** airworthiness
- **Manufacturer:** Textron Lycoming Model O-540-F1B5 Reciprocating
- **Type:** Rule
- **Action:** Final rule; request for comments.
- **Citation:** 64 FR 5149
- **Publication date:** 1999-02-03
- **Effective date:** 1999-02-18
- **FAA docket:** Docket No. 98-ANE-73-AD
## Abstract

This amendment adopts a new airworthiness directive (AD) that is applicable to Textron Lycoming Model O-540-F1B5 reciprocating engines. This action requires the removal and replacement of the crankshaft gear retaining bolts. This amendment is prompted by 2 reported failures of the crankshaft gear retaining bolts. The actions specified in this AD are intended to prevent failure of the crankshaft gear retaining bolts, which can result in engine failure and subsequent autorotation and forced landing.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1999/02/03/99-2474/airworthiness-directives-textron-lycoming-model-o-540-f1b5-reciprocating-engines)
---
*AI Analytics · CC0 1.0*