# Proposed AD 99-NM-380-AD: Boeing Model 737-300, -400, and -500 Series Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2001-02-01
- Action: Notice of proposed rulemaking (NPRM).
- Published: October 18, 2000, 65 FR 62313
- Comments due: December 4, 2000
- Became: [AD 2001-02-01](https://openairdocs.org/ad/2001-02-01)
- Docket: 99-NM-380-AD
- FR document: 00-26711
- Official PDF: https://openairdocs.org/files/sha256/d0/e6/d0e654167206b327054990f7dc96fd90d1d802990df976a6b79bc27ba87da484 (from https://www.govinfo.gov/content/pkg/FR-2000-10-18/pdf/00-26711.pdf)
- Federal Register: https://www.federalregister.gov/documents/2000/10/18/00-26711/airworthiness-directives-boeing-model-737-300--400-and--500-series-airplanes
- Page: https://openairdocs.org/proposed/99-NM-380-AD

## Summary

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 737-300, - 400, and -500 series airplanes. This proposal would require repetitive inspections to detect cracking of certain areas of the forward pressure bulkhead, and repair, if necessary. This proposal also would require certain preventive modifications, which, when accomplished, would terminate the repetitive inspections for the affected areas. This action is necessary to prevent fatigue cracking on critical areas of the forward pressure bulkhead, which could result in rapid decompression of the airplane fuselage. This action is intended to address the identified unsafe condition.

## Notices in this docket

- Oct 18, 2000: Notice of proposed rulemaking (NPRM). (first notice), FR document 00-26711, comments due Dec 4, 2000 (https://www.federalregister.gov/documents/2000/10/18/00-26711/airworthiness-directives-boeing-model-737-300--400-and--500-series-airplanes)

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