AD 2008-17-12 Airworthiness Directives; Airbus Model A318, A319, A320, and A321 Series Airplanes Equipped With Certain Northrop Grumman (Formerly Litton) Air Data Inertial Reference Units

Makes named: grumman. Models named: A318, A319, A320, A321 series. Read the applicability below — it usually turns on serial or part numbers too.

This AD applies to Airbus Model A318, A319, A320, and A321 series airplanes, certificated in any category; equipped with at least one Northrop Grumman (formerly Litton) air data inertial reference unit (ADIRU), part number (P/N) 465020-0303-0307, -0308, -0309, -0312, -0314, -0315, or -0316; except airplanes equipped with three ADIRUs having P/N 465020-0303-0316 and on which Airbus Modification 30650 or 30872 has been incorporated in production, or on which Airbus Service Bulletin A320-25-1248 has been applied in service.

You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done. Restatement of Requirements of AD 2003-26-03 Modification (f) For Model A319, A320, and A321 series airplanes, equipped with any Litton ADIRU installed in accordance with Airbus Modification 24852, 25108, 25336, 26002, or 28218: Within 2 years after January 27, 2004 (the effective date of AD 2003-26-03), do the modifications specified in paragraphs (f)(1), (f)(2), and (f)(3) of this AD, as applicable, in accordance with paragraphs A. through D. of the Accomplishment Instructions of Airbus Service Bulletin A320-25-1248, dated February 16, 2001; or Airbus Service Bulletin A320-25-1248, Revision 01, dated April 16, 2003; as applicable. (1) For all airplanes: Modify the shelf (floor panel) above ADIRU 3 by installing shims between the shelf and the webs of the shelf support structure. (2) For airplanes with Airbus Modification 25900P3941 or Airbus Service Bulletin A320-25-1200 accomplished as of January 27, 2004: Modify the polycarbonate guard (umbrella) protecting the ADIRUs by installing shims between the guard and the shelf support structure. (3) For airplanes with Airbus Modification 23027P2852 or Airbus Service Bulletin A320-52-1038 accomplished as of January 27, 2004: Modify the ladder located in the avionics compartment by machining the slot at the foot of the ladder to increase the depth by 0.236 inch. New Requirements of This AD Modification for Certain Airplanes (g) For all airplanes equipped with any ADIRU installed in accordance with Airbus Modification 31070, 31742, or 35517, except airplanes on which Airbus Modification 30650 or 30872 has been accomplished in production: Within 46 months after the effective date of this AD, modify the ADIRU shelf supports by accomplishing all of the applicable actions specified in the Accomplishment Instructions of Airbus Service Bulletin A320-25-1248, Revision 01, dated April 16, 2003. Replacement of ADIRUs (h) For all airplanes except those on which Airbus Modification 35517 has been incorporated in production: Within 46 months after the effective date of this AD, replace all three ADIRUs with improved ADIRUs having P/N 465020-0303-0316 in accordance with the Accomplishment Instructions of Airbus Service Bulletin A320-34-1350, dated March 20, 2006; or Airbus Service Bulletin A320-34-1350, Revision 01, dated December 12, 2007. Alternative Methods of Compliance (AMOCs) (i) The Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN Tim Dulin, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 227-2141; fax (425) 227-1149. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO. Related Information (j) European Aviation Safety Agency airworthiness directive 2007-0217, dated August 9, 2007, also addresses the subject of this AD. Material Incorporated by Reference (k) You must use service information identified in Table 1 of this AD, as applicable, to perform the actions that are required by this AD, unless the AD specifies otherwise. Table 1—All Material Incorporated by Reference Service bulletin Revision level Date Airbus Service Bulletin A320-25-1248 Original February 16, 2001. Airbus Service Bulletin A320-25-1248 01 April 16, 2003. Airbus Service Bulletin A320-34-1350 Original March 20, 2006. Airbus Service Bulletin A320-34-1350 01 December 12, 2007. (1) The Director of the Federal Register approved the incorporation by reference of the documents identified in Table 2 of this AD in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Table 2—New Material Incorporated by Reference Service bulletin Revision level Date Airbus Service Bulletin A320-25-1248 01 April 16, 2003. Airbus Service Bulletin A320-34-1350 Original March 20, 2006. Airbus Service Bulletin A320-34-1350 01 December 12, 2007. (2) On January 27, 2004 (68 FR 74172, December 23, 2003), the Director of the Federal Register approved the incorporation by reference of Airbus Service Bulletin A320-25-1248, dated February 16, 2001. (3) Contact Airbus, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France, for a copy of this service information. You may review copies at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html. Issued in Renton, Washington, on August 6, 2008. Ali Bahrami, Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. E8-19138 Filed 8-27-08; 8:45 am] BILLING CODE 4910-13-P

This AD results from reports that “NAV IR FAULT” messages have occurred during takeoff due to failure of an ADIRU and subsequent analysis showing that the shelf modification has not sufficiently addressed failure of an ADIRU. We are issuing this AD to prevent failure of an ADIRU during flight, which could result in loss of one source of critical attitude and airspeed data and reduce the ability of the flightcrew to control the airplane.