# Proposed AD 99-NM-90-AD: McDonnell Douglas Model DC-9 Airplanes and Model MD-88 Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2002-26-13
- Products: McDonnell Douglas
- Product type: Aircraft
- Action: Notice of proposed rulemaking (NPRM); reopening of the comment period.
- Published: August 19, 2002, 67 FR 53763
- Comments due: August 26, 2002
- Became: [AD 2002-26-13](https://openairdocs.org/ad/2002-26-13)
- Docket: 99-NM-90-AD
- FR document: 02-20932
- Official PDF: https://openairdocs.org/files/sha256/29/10/291019531750e75291e5397b117f3cace118d50824ea6408582f29b6b6f1c2bb (from https://www.govinfo.gov/content/pkg/FR-2002-08-19/pdf/02-20932.pdf)
- Federal Register: https://www.federalregister.gov/documents/2002/08/19/02-20932/airworthiness-directives-mcdonnell-douglas-model-dc-9-airplanes-and-model-md-88-airplanes
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/4875B6D1C0EA5A3E86256C1A0048A9B9.0001
- Page: https://openairdocs.org/proposed/99-NM-90-AD

## Summary

This document extends the period for public comment on the above-referenced NPRM that would apply to certain McDonnell Douglas Model DC-9 airplanes and Model MD-88 airplanes. The NPRM proposes to require replacement of certain power relays, and subsequent repetitive cleaning, inspecting, repairing, and testing of certain replaced power relays. The NPRM is prompted by reports indicating that the alternating current (AC) cross-tie relay shorted out internally, which caused severe smoke and burn damage to the relay, aircraft wiring, and adjacent panels. This extension of the comment period is necessary to assure that all interested persons have ample opportunity to present their views on the proposed requirements of the NPRM.

## Notices in this docket

- Aug 30, 1999: Notice of proposed rulemaking (NPRM). (first notice), FR document 99-22395, comments due Oct 14, 1999 (https://www.federalregister.gov/documents/1999/08/30/99-22395/airworthiness-directives-mcdonnell-douglas-model-dc-9-and-c-9-military-series-airplanes)
- Jun 14, 2001: Supplemental notice of proposed rulemaking; reopening of comment period., FR document 01-14940, comments due Jul 9, 2001 (https://www.federalregister.gov/documents/2001/06/14/01-14940/airworthiness-directives-mcdonnell-douglas-model-dc-9-series-airplanes-and-model-md-88-airplanes)
- Jul 1, 2002: Supplemental notice of proposed rulemaking; reopening of comment period., FR document 02-16407, comments due Jul 26, 2002 (https://www.federalregister.gov/documents/2002/07/01/02-16407/airworthiness-directives-mcdonnell-douglas-model-dc-9-airplanes-and-model-md-88-airplanes)
- Aug 19, 2002: Notice of proposed rulemaking (NPRM); reopening of the comment period., FR document 02-20932, comments due Aug 26, 2002 (https://www.federalregister.gov/documents/2002/08/19/02-20932/airworthiness-directives-mcdonnell-douglas-model-dc-9-airplanes-and-model-md-88-airplanes)

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