# Proposed AD 99-NM-114-AD: Boeing Model 747-400 and 767 Series Airplanes Powered by Pratt & Whitney PW4000 Series Engines

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 99-26-02
- Action: Notice of proposed rulemaking (NPRM).
- Published: September 15, 1999, 64 FR 50022
- Comments due: November 1, 1999
- Became: [AD 99-26-02](https://openairdocs.org/ad/99-26-02)
- Docket: 99-NM-114-AD
- FR document: 99-24091
- Official PDF: https://openairdocs.org/files/sha256/a9/40/a940489e137954511c7e586c14bde251e40f6913691ace9cab812900d5004673 (from https://www.govinfo.gov/content/pkg/FR-1999-09-15/pdf/99-24091.pdf)
- Federal Register: https://www.federalregister.gov/documents/1999/09/15/99-24091/airworthiness-directives-boeing-model-747-400-and-767-series-airplanes-powered-by-pratt-and-whitney
- Page: https://openairdocs.org/proposed/99-NM-114-AD

## Summary

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 747-400 and 767 series airplanes. This proposal would require replacement of the existing deactivation pin, pin bushing, and insert flange on each thrust reverser half, with new, improved components. This proposal is prompted by reports of partial deployment of deactivated thrust reversers during landing. The actions specified by the proposed AD are intended to prevent failure of the thrust reverser deactivation pins, which could result in deployment of the thrust reverser in flight and consequent reduced controllability of the airplane.

## Notices in this docket

- Sep 15, 1999: Notice of proposed rulemaking (NPRM). (first notice), FR document 99-24091, comments due Nov 1, 1999 (https://www.federalregister.gov/documents/1999/09/15/99-24091/airworthiness-directives-boeing-model-747-400-and-767-series-airplanes-powered-by-pratt-and-whitney)

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.