# Proposed AD 98-SW-80-AD: MD Helicopters Inc. Model 369D, 369E, 369FF, 500N, and 600N Helicopters

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 99-20-12
- Action: Notice of proposed rulemaking (NPRM).
- Published: June 23, 1999, 64 FR 33447
- Comments due: August 23, 1999
- Became: [AD 99-20-12](https://openairdocs.org/ad/99-20-12)
- Docket: 98-SW-80-AD
- FR document: 99-15932
- Official PDF: https://openairdocs.org/files/sha256/df/cd/dfcd50b408cbf3c7f040e54776818a763c7044551d6708a164ef3f39e8376e14 (from https://www.govinfo.gov/content/pkg/FR-1999-06-23/pdf/99-15932.pdf)
- Federal Register: https://www.federalregister.gov/documents/1999/06/23/99-15932/airworthiness-directives-md-helicopters-inc-model-369d-369e-369ff-500n-and-600n-helicopters
- Page: https://openairdocs.org/proposed/98-SW-80-AD

## Summary

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

## Notices in this docket

- Jun 23, 1999: Notice of proposed rulemaking (NPRM). (first notice), FR document 99-15932, comments due Aug 23, 1999 (https://www.federalregister.gov/documents/1999/06/23/99-15932/airworthiness-directives-md-helicopters-inc-model-369d-369e-369ff-500n-and-600n-helicopters)

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