Document ID: chunk:federal_register_of_legislation:F2012L00587:body:0:p2
Version: federal_register_of_legislation:F2012L00587
Segment Type: other
Provision Reference: 
Character Range: 3178–5103

later EASA approved revision.

             Compliance with Requirements 2 and 3 terminates the Requirement 1 despatch restrictions and no further action is required by this Amendment.

             Note 2:  EASA 2007-0217 refers.
Compliance:  For Requirement 1 - As of the effective date of this Amendment.

             For Requirement 2 - Within six months after the effective date of this Amendment.

             For Requirement 3 - Before 31 May 2010.
             This Amendment becomes effective on 16 March 2012.
Background:  Initially, the French Direction Générale de l'Aviation Civile (DGAC) advised that some instances of loss of inertial references have been reported which could reduce the control of the aircraft due to the non-availability of some parameters (attitude, vertical speed, ground speed, etc.).  Subsequent investigation identified the loss of the parameters as being caused by the ADIRU striking the bottom of the upper shelf.

             AD/A320/138 mandated the modification of the ADIRU shelf supports in an attempt to prevent contact between the ADIRUs and the upper shelf.  This measure alone did not prove sufficient and the original issue of this Directive introduced revised despatch limitations for the MMEL.

             Again these measures were found to be insufficient and the European Aviation Safety Agency (EASA) has advised that replacement of the three ADIRUs together with the modification of the shelf will provide terminating action for the despatch limitations.  Consequently, this Amendment continues the despatch limitations, reiterates the shelf modification and requires replacement of the three ADIRUs.

   Amendment 2 of this AD is issued to inform that AD/A320/138 has been cancelled and the requirements contained in that AD have been incorporated in AD/A320/174 Amdt 2.

David Villiers
Delegate of the Civil Aviation Safety Authority

14 March 2012