# Airworthiness Directives; MD Helicopters Inc. Model 369D, D369E, 369FF, 500N, and 600N Helicopters
> **Rule** · Final rule. · Published 1999-09-30 · Effective 1999-11-04 · 64 FR 52649
## Document
- **Document number:** 99-25375
- **Category:** airworthiness
- **Manufacturer:** MD
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 64 FR 52649
- **Publication date:** 1999-09-30
- **Effective date:** 1999-11-04
- **FAA docket:** Docket No. 98-SW-80-AD
## Abstract

This amendment adopts a new airworthiness directive (AD), applicable to MD Helicopters, Inc. Model 369D, 369E, 369FF, 500N, and 600 N helicopters, that requires replacing the oil cooler blower bracket (bracket). This amendment is prompted by three reports of cracked brackets. The actions specified by this AD are intended to prevent failure of a bracket, loss of cooling of engine oil and transmission oil, and subsequent forced landing.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1999/09/30/99-25375/airworthiness-directives-md-helicopters-inc-model-369d-d369e-369ff-500n-and-600n-helicopters)
---
*MORVS · CC0 1.0*