Document ID: chunk:federal_register_of_legislation:F2009L02968:body:0:p2
Version: federal_register_of_legislation:F2009L02968
Segment Type: other
Provision Reference: 
Character Range: 2763–4027

S/B 73-0239 or CFM56-5C S/B 73-0180 is an alternative corrective action for the requirements of this AD.

             The use of later approved revisions of these documents is acceptable for compliance with the requirements of this AD.

             Note 3:  EASA AD 2009-0154-E dated 17 July 2009 refers.
Compliance:  For Requirement 1 - Within 24 hours after the effective date of this AD, unless previously accomplished.

             For Requirement 2 - Before further flight, unless previously accomplished.

             For Requirement 3.a. - Before further flight.

             For Requirement 3.b. - Within 30 days after the effective date of this AD.
             This Airworthiness Directive becomes effective on 27 July 2009.
Background:  In-flight compressor stall events have occurred on CFM56-5B turbofan engines.  These events could have been caused by malfunction of the HMU Variable Stator Vanes (VSV)/Variable Bleed Valves (VBV) Scored Vanes and could lead to in-flight shutdown of the engine, which can result in a catastrophic effect at aircraft level if more than one engine is affected.  This AD mandates the inspection and replacement of the affected HMUs.

James Coyne
Delegate of the Civil Aviation Safety Authority

23 July 2009