# Proposed AD 2000-NM-251-AD: Boeing Model 747 Series Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 2001-14-07
- Action: Notice of proposed rulemaking (NPRM).
- Published: February 21, 2001, 66 FR 10974
- Comments due: April 9, 2001
- Became: [AD 2001-14-07](https://openairdocs.org/ad/2001-14-07)
- Docket: 2000-NM-251-AD
- FR document: 01-4219
- Official PDF: https://openairdocs.org/files/sha256/5c/0c/5c0c8dac664462774cc42f04cf6dad7e97199332aeb969be8756dc0fdfcd5aa9 (from https://www.govinfo.gov/content/pkg/FR-2001-02-21/pdf/01-4219.pdf)
- Federal Register: https://www.federalregister.gov/documents/2001/02/21/01-4219/airworthiness-directives-boeing-model-747-series-airplanes
- Page: https://openairdocs.org/proposed/2000-NM-251-AD

## Summary

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Boeing Model 747 series airplanes. This proposal would require repetitive high frequency eddy current inspections to find cracking of the bulkhead frame support at body station 2598 under the hinge support fittings of the horizontal stabilizer, and repair if cracking is found. This action is necessary to find and fix fatigue cracking in the frame support, which could result in inability of the structure to carry horizontal stabilizer flight loads and reduced controllability of the horizontal stabilizer. This action is intended to address the identified unsafe condition.

## Notices in this docket

- Feb 21, 2001: Notice of proposed rulemaking (NPRM). (first notice), FR document 01-4219, comments due Apr 9, 2001 (https://www.federalregister.gov/documents/2001/02/21/01-4219/airworthiness-directives-boeing-model-747-series-airplanes)

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