# Proposed AD 98-NM-69-AD: McDonnell Douglas Model MD-90-30

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 99-18-23
- Action: Notice of proposed rulemaking (NPRM).
- Published: March 2, 1999, 64 FR 10113
- Comments due: April 16, 1999
- Became: [AD 99-18-23](https://openairdocs.org/ad/99-18-23)
- Docket: 98-NM-69-AD
- FR document: 99-5043
- Official PDF: https://openairdocs.org/files/sha256/88/64/88649f3938b88f04fbcdf01d6ab81d4dca8c482da8702cac11065663d10345ea (from https://www.govinfo.gov/content/pkg/FR-1999-03-02/pdf/99-5043.pdf)
- Federal Register: https://www.federalregister.gov/documents/1999/03/02/99-5043/airworthiness-directives-mcdonnell-douglas-model-md-90-30
- Page: https://openairdocs.org/proposed/98-NM-69-AD

## Summary

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all McDonnell Douglas MD-90-30 series airplanes. This proposal would require revising the Airworthiness Limitations Section of the Instructions for Continued Airworthiness [MD-90-30 Airworthiness Limitations Instructions (ALI)] to incorporate certain replacement times for safe-life limited parts. This proposal is prompted by analysis of data that identified reduced replacement times for certain safe-life limited parts. The actions specified by the proposed AD are intended to prevent fatigue cracking of various safe-life limited parts; such fatigue cracking could adversely affect the structural integrity of these airplanes.

## Notices in this docket

- Mar 2, 1999: Notice of proposed rulemaking (NPRM). (first notice), FR document 99-5043, comments due Apr 16, 1999 (https://www.federalregister.gov/documents/1999/03/02/99-5043/airworthiness-directives-mcdonnell-douglas-model-md-90-30)

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