# Airworthiness Directives; Boeing Model 747 -400 and -400D Series Airplanes
> **Rule** · Final rule; request for comments. · Published 2004-04-28 · Effective 2004-05-13 · 69 FR 23098
## Document
- **Document number:** 04-9378
- **Category:** airworthiness
- **Manufacturer:** Boeing Model 747 -400 and -400D Series
- **Type:** Rule
- **Action:** Final rule; request for comments.
- **Citation:** 69 FR 23098
- **Publication date:** 2004-04-28
- **Effective date:** 2004-05-13
- **FAA docket:** Docket No. 2004-NM-42-AD
## Abstract

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747-400 and 400D series airplanes. This action requires installation of tie bars on the rails of the center passenger service units (PSU) panel in Zone A. This action is necessary to prevent PSU panels from moving and falling from the PSU support rails during takeoff and landing, which could result in injury to passengers and could impede evacuation of the passengers in an emergency situation. This action is intended to address the identified unsafe condition.

## Source
- [Federal Register document](https://www.federalregister.gov/documents/2004/04/28/04-9378/airworthiness-directives-boeing-model-747--400-and--400d-series-airplanes)
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