# Proposed AD 98-NM-16-AD: Fokker Model F.28 Mark 1000, 2000, 3000, and 4000 Series Airplanes

- Type: Proposed airworthiness directive (not in force)
- Status: Became AD 98-13-25
- Action: Notice of proposed rulemaking (NPRM).
- Published: April 27, 1998, 63 FR 20554
- Comments due: May 27, 1998
- Became: [AD 98-13-25](https://openairdocs.org/ad/98-13-25)
- Docket: 98-NM-16-AD
- FR document: 98-11092
- Official PDF: https://openairdocs.org/files/sha256/83/c4/83c40aa14ebc0446cab42f7f9c931fa345a7f8696baef6b21d4861b48a6737ca (from https://www.govinfo.gov/content/pkg/FR-1998-04-27/pdf/98-11092.pdf)
- Federal Register: https://www.federalregister.gov/documents/1998/04/27/98-11092/airworthiness-directives-fokker-model-f28-mark-1000-2000-3000-and-4000-series-airplanes
- Page: https://openairdocs.org/proposed/98-NM-16-AD

## Summary

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Fokker Model F.28 Mark 1000, 2000, 3000, and 4000 series airplanes, that currently requires an inspection to detect free movement of the actuator servo- valve sub-assembly of the horizontal stabilizer actuator, and replacement, if necessary. This action would add a one-time inspection to determine the residual strength of the servo-valve sub-assembly of the horizontal stabilizer actuator, and replacement of the actuator with a new or serviceable actuator, if necessary; and eventual replacement of the horizontal stabilizer actuator with an improved actuator. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to prevent uncommanded trimming or failure of the trim system of the horizontal stabilizer, and consequent reduced controllability of the airplane.

## Notices in this docket

- Apr 27, 1998: Notice of proposed rulemaking (NPRM). (first notice), FR document 98-11092, comments due May 27, 1998 (https://www.federalregister.gov/documents/1998/04/27/98-11092/airworthiness-directives-fokker-model-f28-mark-1000-2000-3000-and-4000-series-airplanes)

---
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.