{"id":"F2008L03082","name":"AD/AB139/7 - Tail Boom Assembly","slug":"ad-ab139-7-tail-boom-assembly","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":75117,"registerId":"commonwealth-F2008L03082-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"Agusta AB139 and AW139 Series Helicopter","sectionType":"division","heading":"Agusta AB139 and AW139 Series Helicopters","content":"### Agusta AB139 and AW139 Series Helicopters\n\n```html\n

AD/AB139/7

Tail Boom Assembly

10/2008 DM

Applicability:

AB139 and AW139 helicopters, all serial numbers, if a tail boom assembly Part Number (P/N) 3G5350A00131, P/N 3G5350A00132, P/N 3G5350A00133 or P/N 3G5350A00134 is installed.

Requirement:

Action in accordance with EASA AD 2008-0157.

Note: Agusta Bollettino Tecnico (BT) 139-134 refers.

Compliance:

Required as indicated in the requirement document.

Note: Report all defects to CASA (via SDR) and the type certificate holder.

This Airworthiness Directive becomes effective on 27 August 2008.

Background:

Some operators of AB/AW139 helicopters have reported finding debonding of fuselage tail boom panels. This condition, if not detected and corrected, could lead to the structural collapse of the tail boom installation, resulting in loss of control of the helicopter.

This directive requires repetitive inspections of the tail boom assembly and the reporting of defects to CASA and the type certificate holder.

\n```\n\n![](image.001.png) \nDavid Villiers \nDelegate of the Civil Aviation Safety Authority\n\n15 August 2008","sortOrder":0},{"sectionNumber":"AD/AB139/7","sectionType":"part","heading":"AD/AB139/7","content":"## AD/AB139/7","sortOrder":1},{"sectionNumber":"Tail Boom Assembly","sectionType":"part","heading":"Tail Boom Assembly","content":"## Tail Boom Assembly","sortOrder":2},{"sectionNumber":"10/2008 DM","sectionType":"part","heading":"10/2008 DM","content":"## 10/2008 DM","sortOrder":3}],"analysis":{"summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This airworthiness directive was made effective on 27 August 2008 and remains an existing continuing airworthiness requirement. It does not amend, repeal or replace any other legislative instrument; it simply mandates compliance with an existing EASA directive under the Australian regulatory framework."},"complexity_factors":["Cross-references and incorporates a foreign regulation (EASA AD 2008-0157) by reference, requiring the reader to obtain and understand a separate European document","Relies on manufacturer technical bulletin (Agusta BT 139-134) for detailed inspection procedures, adding a layer of technical documentation","Uses specific aircraft component part numbers that must be cross-checked against physical installations","Imposes dual defect-reporting obligations (CASA SDR system and type certificate holder) which may not be immediately obvious to all operators"],"plain_english_summary":"This CASA airworthiness directive mandates repetitive inspections of AB139/AW139 helicopters fitted with certain tail boom assemblies, after reports of panel debonding that can lead to tail boom structural failure and loss of control. Operators must follow the inspection procedures and timing in the referenced EASA AD and Agusta technical bulletin, and report any defects to CASA (SDR) and the manufacturer."}},"importantCases":[],"_links":{"self":"/api/acts/ad-ab139-7-tail-boom-assembly","history":"/api/acts/ad-ab139-7-tail-boom-assembly/history","analysis":"/api/acts/ad-ab139-7-tail-boom-assembly/analysis","conflicts":"/api/acts/ad-ab139-7-tail-boom-assembly/conflicts","importantCases":"/api/acts/ad-ab139-7-tail-boom-assembly/important-cases","documents":"/api/acts/ad-ab139-7-tail-boom-assembly/documents"}}