2009-04-07: Nose down order

2009-04-07 Airbus: Amendment 39-15813. Docket No. FAA-2009-0122; Directorate Identifier 2008-NM-223-AD. Effective Date (a) This airworthiness directive (AD) becomes effective March 5, 2009. Affected ADs (b) None. Applicability (c) This AD applies to Airbus Model A330-200 and -300; and A340- 200, -300, -500, and -600 series airplanes, certificated in any category, as listed in paragraphs (c)(1) and (c)(2) of this AD. (1) A330-201, -202, -203, -223, -243, -301, -302, -303, -321, - 322, -323, -341, -342, and -343 airplanes, all serial numbers, equipped with Northrop-Grumman (formerly Litton) Air Data Inertial Reference Units (ADIRUs), part number (P/N) 465020-0303-03ZZ (with ZZ from 09 up to 16 inclusive). (2) A340-211, -212, -213, -311, -312, -313, -541, and -642 airplanes, all serial numbers, equipped with Northrop-Grumman (formerly Litton) ADIRUs, P/N 465020-0303-03ZZ (with ZZ from 09 up to 16 inclusive). Subject (d) Air Transport Association(ATA) of America Code 34: Navigation. Reason (e) The mandatory continued airworthiness information (MCAI) states: An A330 aircraft experienced a sudden [uncommanded] nose down order [event] while in cruise. This order was preceded by an automatic autopilot disconnection and triggering of the "NAV IR1 FAULT'' Electronic Centralised Aircraft Monitor (ECAM) Caution. Investigations highlighted that at time of the event the Air Data Reference 1 (ADR) part of ADIRU1 [Air Data Inertial Reference Unit] was providing erroneous and temporary wrong parameters in a random manner. This abnormal behaviour of the ADR1 led to several consequences such as unjustified stall and over speed warnings, loss of attitude information on Captain Primary Flight Display (PFD) and several ECAM warnings. Among the abnormal parameters, the provided Angle of Attack (AoA) value was such that the flight control computers commanded a sudden [uncommanded] nose down aircraft movement, which constitutes anunsafe condition. At this stage of the investigation, the analysis of available data indicates that ADIRU1 abnormal behaviour is likely at the origin of the event. Due to similar design, the A340 aircraft are also impacted by this issue. In order to prevent the ADR from providing erroneous data to other aircraft systems, EASA [Emergency] AD 2008-0203-E [dated November 19, 2008] was issued to require, in case faulty Inertial Reference (IR) is detected, to isolate both the IR and ADR by accomplishment of a modified Aircraft Flight Manual (AFM) operational procedure. Since that AD [EASA AD 2008-0203-E, dated November 19, 2008] was issued, it has been reported that the "OFF'' light did not illuminate in the cockpit after setting the IR and ADR pushbuttons to OFF. Investigation has determined that the ADIRU was indeed sometimes affected by another failure control. To prevent such a failure, the operational procedure has been updated to instruct the flight crew to de-energize the ADIRU if the "OFF'' light is not illuminated after setting the IR and ADR pushbuttons to OFF. Consequently, [EASA Emergency] AD 2008-0225-E [dated December 18, 2008], which superseded [EASA Emergency] AD 2008-0203-E [dated November 19, 2008], requires accomplishment of the updated AFM operational procedure. Since this second AD was issued [EASA Emergency AD 2008-0225-E, dated December 18, 2008], a new service event has been reported highlighting that, in some failure cases, even though the "OFF'' light illuminates in the cockpit after setting the IR and ADR pushbuttons to OFF, the IR could keep providing erroneous data to other systems. In order to address all identified failure cases, de-energizing the affected ADIRU must be done by setting the IR mode rotary selector to OFF. Consequently, this AD, which supersedes AD 2008-0225-E [dated December 18, 2008], requires accomplishment of the updated AFM operational procedure. The anomalies described above could result in high pilotworkload, deviation from the intended flight path, and possible loss of control of the airplane. Actions and Compliance (f) Unless already done: Within 14 days after the effective date of this AD, revise the applicable section of the A330 or A340 (Airbus) Flight Manual (FM) by inserting a copy of A330 (Airbus) Temporary Revision (TR) 4.02.00/46, or A340 (Airbus) TR 4.02.00/54, both Issue 3, both dated January 13, 2009, as applicable. Thereafter, operate the airplane according to the limitations and procedures in the TRs. When information identical to that in the TR has been included in the general revisions of the FM, the general revisions may be inserted in the FM, and the TR may be removed. FAA AD Differences Note 1: This AD differs from the MCAI and/or service information as follows: No differences. Other FAA AD Provisions (g) The following provisions also apply to this AD: (1) Alternative Methods of Compliance (AMOCs): 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: Vladimir Ulyanov, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 227-1138; fax (425) 227-1149. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. (2) Airworthy Product: For any requirement in this AD to obtain corrective actions from a manufacturer or other source, use these actions if they are FAA-approved. Corrective actions are considered FAA-approved if they are approved by the State of Design Authority (or their delegated agent). You are required to assure the product is airworthy before itis returned to service. (3) Reporting Requirements: For any reporting requirement in this AD, under the provisions of the Paperwork Reduction Act, the Office of Management and Budget (OMB) has approved the information collection requirements and has assigned OMB Control Number 2120- 0056. Related Information (h) Refer to MCAI European Aviation Safety Agency Emergency Airworthiness Directive 2009-0012-E, dated January 15, 2009; A330 (Airbus) TR 4.02.00/46, Issue 3, dated January 13, 2009; and A340 (Airbus) TR 4.02.00/54, Issue 3, dated January 13, 2009; for related information. Material Incorporated by Reference (i) You must use A330 (Airbus) Temporary Revision 4.02.00/46, Issue 3, dated January 13, 2009, to the A330 (Airbus) Flight Manual; or A340 (Airbus) Temporary Revision 4.02.00/54, Issue 3, dated January 13, 2009, to the A340 (Airbus) Flight Manual; as applicable; to do the actions required by this AD, unless the AD specifies otherwise. (1) The Director ofthe Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51. (2) For service information identified in this AD, contact Airbus SAS--Airworthiness Office--EAL, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France; fax +33 5 61 93 45 80; e-mail [email protected]; Internet http://www.airbus.com. (3) You may review copies of the service information that is incorporated by reference at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221 or 425-227-1152. (4) You may also review copies of the service information 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/code_of_federal_ regulations/ibr_locations.html.