# Proposed AD 98-SW-42-AD: McDonnell Douglas Helicopter Systems Model MD-900 Helicopters

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 99-16-13
- Action: Notice of proposed rulemaking (NPRM).
- Published: April 28, 1999, 64 FR 22818
- Comments due: June 28, 1999
- Became: [AD 99-16-13](https://openairdocs.org/ad/99-16-13)
- Docket: 98-SW-42-AD
- FR document: 99-10619
- Official PDF: https://openairdocs.org/files/sha256/24/da/24dad0f5520237a5c2579ec4e38d6fbcffed5ea4fb24b53d390520851bd66cf8 (from https://www.govinfo.gov/content/pkg/FR-1999-04-28/pdf/99-10619.pdf)
- Federal Register: https://www.federalregister.gov/documents/1999/04/28/99-10619/airworthiness-directives-mcdonnell-douglas-helicopter-systems-model-md-900-helicopters
- Page: https://openairdocs.org/proposed/98-SW-42-AD

## Summary

This document proposes to supersede an existing airworthiness directive (AD), applicable to McDonnell Douglas Helicopter Systems (MDHS) Model MD-900 helicopters, that currently requires applying specified serial numbers and establishing life limits for certain parts. This proposal is prompted by additional analysis that supports an increase in the life limits of certain parts. The actions specified by this AD are intended to increase the life limits for various parts.

## Notices in this docket

- Apr 28, 1999: Notice of proposed rulemaking (NPRM). (first notice), FR document 99-10619, comments due Jun 28, 1999 (https://www.federalregister.gov/documents/1999/04/28/99-10619/airworthiness-directives-mcdonnell-douglas-helicopter-systems-model-md-900-helicopters)

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.