# Airworthiness Directives; McDonnell Douglas Model DC-9 and DC-9- 80 Series Airplanes, Model MD-88 Airplanes, and C-9 (Military) Series Airplanes
> **Rule** · Final rule. · Published 1998-12-03 · Effective 1999-01-07 · 63 FR 66739
## Document
- **Document number:** 98-31698
- **Category:** airworthiness
- **Manufacturer:** McDonnell Douglas Model DC-9 and DC-9- 80 Series
- **Type:** Rule
- **Action:** Final rule.
- **Citation:** 63 FR 66739
- **Publication date:** 1998-12-03
- **Effective date:** 1999-01-07
- **FAA docket:** Docket No. 97-NM-21-AD
## Abstract

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9 and DC-9-80 series airplanes, Model MD-88 airplanes, and C-9 (military) series airplanes, that requires a one-time visual inspection to detect fatigue cracking of the lower left nose of certain longerons and the attaching frames; repair, if necessary; and installation of a preventive modification. This amendment is prompted by several reports of fatigue cracking of certain longerons and the attaching frames. The actions specified by this AD are intended to prevent such fatigue cracking, which could result in reduced structural integrity of the fuselage, and consequent loss of pressurization of the airplane.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/1998/12/03/98-31698/airworthiness-directives-mcdonnell-douglas-model-dc-9-and-dc-9--80-series-airplanes-model-md-88)
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