Federal Register of Legislation - Australian Government

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AD/BELL 206/169 - Exhaust Duct Grooved Clamps

Authoritative Version
AD/BELL 206/169 Airworthiness Directives/Pt 105 — Aircraft as made
Exhaust Duct Grooved Clamps
Administered by: Infrastructure, Transport, Regional Development and Communications
Exempt from sunsetting by the Legislation (Exemptions and Other Matters) Regulation 2015 s12 item 15
Registered 17 May 2007
Tabling HistoryDate
Tabled HR21-May-2007
Tabled Senate12-Jun-2007



For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Bell Helicopter Textron Canada (BHTC) 206 and Agusta Bell 206 Series Helicopters

AD/BELL 206/169

Exhaust Duct Grooved Clamps




Agusta AB206A and AB206B series helicopters.


1.    Inspect the grooved clamps P/N 4656AA or P/N 4606AC fixing the engine exhaust duct in accordance with Agusta “Bollettino Tecnico” 206-242 dated
18 December 2006 or later approved revisions.

2.    In any cracks and/or corrosion are found, discard and replace the affected grooved clamp.

Note:  EASA AD 2007-0043 dated 21 February 2007 refers.


1.    Within the next 50 hours time in service (TIS) or within 30 days after the effective date of this AD whichever occurs first.  Thereafter repeat every 100 flight hours or yearly, whichever occurs first.

2.    Before further flight after the effective date of this AD.


This Airworthiness Directive becomes effective on 7 June 2007.


An A109A helicopter had a failure of the grooved clamp fixing the engine exhaust duct, with the consequent loss of the duct.  The duct hit the main and tail rotor producing the loss of the tail rotor and the emergency landing of the helicopter.

Taking into account the occurrence reported above as well as the commonality between the exhaust duct installations for A109 and AB206 helicopters, Agusta issued “Bollettino Tecnico” 206-242 to require a visual inspection of the grooved damps for cracks and/or for corrosion, in order to ensure the continued airworthiness of the helicopters.

David Punshon
Delegate of the Civil Aviation Safety Authority

26 April 2007