Federal Register of Legislation - Australian Government

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AD/BELL/222/38 Airworthiness Directives/Pt 105 — Aircraft as made
Power Turbine RPM Steady-State Operation
Administered by: Infrastructure, Transport, Regional Development and Communications
Exempt from sunsetting by the Legislation (Exemptions and Other Matters) Regulation 2015 s12 item 15
Registered 06 Jul 2007
Tabling HistoryDate
Tabled HR07-Aug-2007
Tabled Senate07-Aug-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) 222 Series Helicopters

AD/BELL 222/38

Power Turbine RPM Steady-State Operation




Bell Helicopter Textron Canada (BHTC) Model 230 helicopters, serial numbers 23001 through 23038.


1.    Insert flight manual BHT-230-FM-1 Revision 5, or later approved revisions, into the rotorcraft flight manual and advise the pilot of this change.

2.    Install the decal as per Alert Service Bulletin 230-05-33, dated 10 June 2005, or later NAA approved revisions.

Note:  Transport Canada AD CF-2005-24 dated 4 July 2005 refers.


1.    Within 30 calendar days after the effective date of this directive, unless previously accomplished.

2.    In conjunction with Requirement 1 of this AD.


This Airworthiness Directive becomes effective on 2 August 2007.


Transport Canada has advised of multiple reports of failure of the third stage turbine wheel used in both the Rolls-Royce 250-C3OS and 250-C47B engines.  There have been six in-flight failures of which three have occurred on the engine utilized by BHTC for the Model 230 helicopter.  Rolls-Royce has determined that detrimental vibrations can occur within a particular range of turbine speed as a potential contributing factor to these failures.  BHTC revised their rotorcraft flight manual and provided a decal to inform pilots to avoid steady-state operations at these engine turbine speeds.

David Punshon
Delegate of the Civil Aviation Safety Authority

21 June 2007