AD 2008-12-18

(a) This airworthiness directive (AD) becomes effective July 23, 2008.

(b) None.

(c) This AD applies to Dassault Model Falcon 2000EX airplanes, serial number (S/N) 6, and S/N 28 and subsequent; and Model Falcon 900EX airplanes, S/N 97, and S/N 120 and subsequent; certificated in any category.

(d) Air Transport Association (ATA) of America Code 34: Navigation.

(e) The mandatory continuing airworthiness information (MCAI) states:

During a flight test performed on an EASy aircraft, subsequently to an air data probe failure, the crew realized that the Flight path vectors and the Vertical speeds that were displayed on pilot's and co-pilot's PDU (primary display unit) were identically wrong.

A review of the EASy architecture reveals that the current wiring of Air Data System (ADS) and IRS (inertial reference system) units is not compliant with the certified safety objectives. All IRS primary inputs are wired to the same General Purpose (GP) Bus and thus basic requirements for ADS segregation are not met. One single ADS unflagged air data error may lead to the computation and display on both pilot's and co-pilot's display units of unnoticed and misleading flight information.

At take-off or during go-around this situation might considerably reduce flight safety.

This AD mandates a wiring modification of IRS [no.] 2 and a test of General Purpose bus IRS entry per application of SB-F2000EX-89 on Falcon 2000EX EASy and per application of SB-F900EX-274 on Falcon 900EX EASy.

Furthermore in order to maintain ADS parameter segregation against possible failures, this AD also requires F2000EX EASy and F900EX EASy operators to comply with the modifications made to the respective Chapter 5.40 of the Aircraft Maintenance Manuals that contain an additional periodic functional test of the IRS GP Bus I/O (input/output).

Dispatch conditions under MMEL (master minimum equipment list) in case of an IRS2 failure are modified after implementation of the wiring change.

The corrective actions involve checking the integrity of the GP bus and IRS2, and repairing them as applicable.

(f) Unless already done, do the following actions.

(1) For Model Falcon 2000EX airplanes without Dassault Modification M2758 and Model Falcon 900EX airplanes without Dassault Modification M5143 in the applicability range: Within 3 months after the effective date of this AD, do the IRS2 wiring modification and test the GP (general purpose) bus IRS entry. Do all actions in accordance with the Accomplishment Instructions of Dassault Service Bulletin F2000EX-89, dated March 17, 2006; or Dassault Service Bulletin F900EX-274, dated March 17, 2006; as applicable. Repeat the test at intervals not to exceed 5,000 flight hours. If the GP bus IRS entry fails any test, before further flight, do all applicable corrective actions in accordance with the procedures in Section 34-209, dated March 2007, of the Dassault Falcon 900EX EASy/900DX Maintenance Manual; or Section 34-209, dated May 2007, of the Dassault Falcon 2000EX EASy Maintenance Manual; as applicable.

(2) For Model Falcon 2000EX airplanes with Dassault Modification M2758 and Model Falcon 900EX airplanes with Dassault Modification M5143 in the applicability range: Within 5,000 flight hours after the date of issuance of the original French standard airworthiness certificate or the date of issuance of the original French export certificate of airworthiness, or within 3 months after the effective date of this AD, whichever occurs later, do a test of the GP bus IRS entry in accordance with the Accomplishment Instructions of Dassault Service Bulletin F2000EX-89, dated March 17, 2006; or Dassault Service Bulletin F900EX-274, dated March 17, 2006; as applicable. Repeat the test at intervals not to exceed 5,000 flight hours. If the GP bus IRS entry fails any test, before further flight, do the corrective actions in accordance with the procedures in Section 34-209, dated March 2007, of the Dassault Falcon 900EX EASy/900DX Maintenance Manual; or Section 34-209, dated May 2007, of the Dassault Falcon 2000EX EASy Maintenance Manual; as applicable.

Note:

This AD differs from the MCAI and/ or service information as follows:

(1) Where the MCAI specifies to do a test of the GP bus IRS entry in accordance with Chapter 5.40 of the applicable Dassault Maintenance Manual and does not specify a corrective action, we require those corrective actions to be done in accordance with Section 34-209, dated March 2007, of the Dassault Falcon 900EX EASy/900DX Maintenance Manual; or Section 34-209, dated May 2007, of the Dassault Falcon 2000EX EASy Maintenance Manual; as applicable.

(2) The MCAI specified to revise the applicable Dassault MMEL by incorporating Dassault Temporary Change 4, dated June 15, 2006, to the Dassault Falcon 2000EX EASy MMEL (for Model F2000EX EASy airplanes); and Dassault Temporary Change 3, dated June 15, 2006, to the Dassault Falcon 900EX EASy MMEL (for Model F900EX EASy airplanes); as applicable. However, the FAA-approved MMEL (which is required to be used by operators) has been revised to include the information specified in the Dassault temporary changes. Therefore, we have not included a requirement for this revision in this AD.

(g) The following provisions also apply to this AD:

(1) Alternative Methods of Compliance (AMOCs): The Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Tom Rodriguez, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 227-1137; 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.

(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 it is 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.

(h) Refer to MCAI European Aviation Safety Agency (EASA) Airworthiness Directive 2006-0157, dated June 7, 2006; Section 34-209, dated March 2007, of the Dassault Falcon 900EX EASY/900DX Maintenance Manual; Section 34-209, dated May 2007, of the Dassault Falcon 2000EX EASy Maintenance Manual; and Dassault Service Bulletins F2000EX-89 and F900EX-274, both dated March 17, 2006; for related information.

(i) You must use the service information specified in Table 1 of this AD to do the actions required by this AD, as applicable, unless the AD specifies otherwise.

(1) The Director of the 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 Dassault Falcon Jet, P.O. Box 2000, South Hackensack, New Jersey 07606.

(3) 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.