Commonwealth legislation

AD/GAF-N22/28 Amdt 4 - Horizontal Stabiliser and Trim Tab System

In ForceCTH

Jurisdiction

Commonwealth

Collection

legislative instrument

Plain English Summary

3/10 complexity

This airworthiness directive requires owners/operators of GAF N22 and N24 series aeroplanes to carry out a specific modification (per GAF SB NMD-55-12, Mod. N439) and to inspect the horizontal stabiliser and trim tab system per GAF SB NMD-55-5 Revision 4. It responds to an in‑flight incident where part of the trim tab was lost. Compliance requires immediate modification if not done, and recurring inspections tied to maintenance releases and a 110‑hour interval, with costs and work falling to aircraft operators and their maintenance organisations.

JSON API

Deep dive

Want the full deep dive?

Zoe can write the in-depth analysis on top of the summary above: how it works, who it affects and what each part actually does.

Current sections

Direct links to the current provisions in AD/GAF-N22/28 Amdt 4 - Horizontal Stabiliser and Trim Tab System.

AD/GAF-N22/28 Amdt 4 - Horizontal Stabiliser and Trim Tab System

COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY

SCHEDULE OF AIRWORTHINESS DIRECTIVES

View image in the official source
GAF N22 and N24 Series Aeroplanes

AD/GAF-N22/28

Amdt 4

Horizontal Stabiliser and Trim Tab System 7/93

Applicability: All N22 and N24 Series. Requirement: Unless already accomplished:

Modify in accordance with GAF SB NMD-55-12 (Mod. N439).

2. Inspect in accordance with GAF SB NMD-55-5 Revision 4\. Compliance: 1. Forthwith.

2. Prior to the next inspection for maintenance release issue after 30 November 1986, and thereafter at intervals not exceeding 110 hours time in service.

The Compliance of this Directive remains unchanged. This Amendment is effective from 24 June 1993.

Background: An inflight incident occurred which involved extreme vibration in the empennage area and the loss of 150mm of the outboard section of the horizontal stabiliser trim tab.

Amendment 3 reflected the latest revision of SB NMD-55-5, and incorporated the intent of AD/GAF-N22/38 which had been cancelled. Amendment 4 is issued in response to Revision 4 of the Requirement 2 Document which changes the Applicability to include all models.

Source text

Sourced from the Federal Register of Legislation (legislation.gov.au), CC BY 4.0.

1 AD/GAF-N22/28 Amdt 4 - Horizontal Stabiliser and Trim Tab System