Bell Helicopter Textron Canada (BHTC) 22
Bell Helicopter Textron Canada (BHTC) 222 Series Helicopters
Bell Helicopter Textron Canada (BHTC) 222 Series Helicopters
| AD/BELL 222/38 | Power Turbine RPM Steady-State Operation | 8/2007 |
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| Applicability: | Bell Helicopter Textron Canada (BHTC) Model 230 helicopters, serial numbers 23001 through 23038. |
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| Requirement: | 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. |
| Compliance: | 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. | |
| Background: | 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. |
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David Punshon
Delegate of the Civil Aviation Safety Authority
21 June 2007