EASA AD No : 2010–0073

EASA Form 112 Page 1/3 

## EASA AIRWORTHINESS DIRECTIVE

AD No.: 2010-0073

Date: 15 April 2010
Note: This Airworthiness Directive (AD) is issued b y EASA, acting in accordance with Regulation (EC) No 216/2008 on behalf of the Europe an Community, its Member States and of the European third countries that participate in the activities of EASA under Article 66 of that Regulation. This AD is issued in accordance with EC 1702/2003, Part 21A.3B. In accordance with EC 2042/2003 Annex I, Part M.A.301, the continuing airworthiness of an aircraft shall be en sured by accomplishing any applicable ADs. Conseque ntly, no person may operate an aircraft to which an AD applies, except in accordance with the requirements of that AD unle ss otherwise specified by the Agency [EC 2042/2003 Annex I, Part M.A.303] or agre ed with the Authority of the State of Registry [EC 216/2008, Article 14(4) exemption]. 

### Type Approval Holder’s Name : DASSAULT AVIATION 

### Type/Model designation(s) : FALCON 7X

TCDS Number : EASA.A.155 Foreign AD : Not applicable Supersedure : None



### ATA 24 Electrical Power - Transient Voltage Suppressor Di odes –

Inspection/Replacement

Manufacturer(s): Dassault Aviation Applicability: Falcon 7X aeroplanes, all serial num bers except those on which modification Dassault Aviation M724 is embodied.
Reason: Several in service events related to variou s electrical systems, have led to the discovery of a common root cause: a leakage failure mode of Transient Voltage Suppressor (TVS) diodes used on Power Distr ibution Control Units (PDCU) cards or Generator Control Unit (GCU) cards in the Primary Power Distribution Boxes (PPDB). Due to such TVS diode fa ilure mode, operation of some electrical circuits is degraded and some contr ol signals are set at unexpected levels. Further analysis indicated that combination of a TVS diode failure with other systems failures could significa ntly reduce flight safety. To prevent and correct this condition, some Airplan e Flight Manual (AFM) procedures have been modified to reduce the time of exposure to further failures whenever a TVS diode failure occurs. Addit ionally, a field tester has been developed to test all TVS diodes installed on the PDCU and GCU cards for the detection of components beyond acceptable t olerances. The criteria for PDCU or GCU card replacement in case of detection o f faulty components have been identified. This AD requires the accomplishment of the revised AFM procedures, the testing and, as necessary, the replacement of the a ffected PDCU and GCUEASA AD No : 2010–0073

EASA Form 112 Page 2/3 cards. Meanwhile, Dassault Aviation is developing a modifi cation (M724), to improve PDCU and GCU cards, with TVS diodes having reduced susceptibility to the leakage failure mode. Effective Date: 29 April 2010 Required Action(s) and Compliance Time(s): Required as indicated, unless accomplished previous ly: (1) After the effective date of this AD, amend the F7X AFM sub-section abnormal procedures and the Quick Reference Handboo k 2 (QRH 2) subsections abnormal ELEC and HYD as indicated below:



### o Upon display of ELEC:BUS MISCONFIG TIED in Crew Alerting System (Abnormal procedure 3-190-20), land at nearest suitable airport o Upon display of ELEC:LH ESS PWR LO or ELEC:LH ESS NO PWR (Abnormal procedure 3-190-40), land at neare st suitable airport o Upon display of ELEC:RH ESS PWR LO and ELEC:RH ESS NO PWR (Abnormal procedure 3-190-45), land at neare st suitable airport o Upon display of HYD:BACKUP PUMP HI TEMP (Abnormal procedure 3-250-15), set off the pump and if the ba ckup pump is still rotating (green) in hydraulic synoptic, de scend to a safe altitude or below 15,000 ft Caution: These temporary amendments take precedence over the same procedures displayed through the Electronic Check L ist (ECL) in the aeroplane. (2) Pending incorporation of these changes into the next revision of the AFM, compliance with paragraph (1) of this AD may be dem onstrated inserting a copy of this AD into the AFM, subsection Abnormal Procedures 3-190- 20, 3-190-40, 3-190-45 and 3-250-15, into the QRH2, subsections Abnormal ELEC and HYD. (3) For the aeroplane serial numbers included in th e effectivity of Dassault Aviation Falcon 7X Service Bulletin (SB) n° 133, wi thin 9 months after the effective date of this AD inspect the PDCU and GCU cards in accordance with the instructions of the SB. In case of detection of faulty components, before further flight remove and replac e the affected PDCU and GCU cards in accordance with the instructions o f Dassault Aviation SB n°133. (4) Accomplishment of Goodrich Service Bulletins 80 232190-24-01, 80232191-24-01 and 80232192-24-01 is also acceptabl e to comply with the requirements of paragraph (3) of this AD.

Ref. Publications: - F7X AFM DGT105608 Rev 8. - Dassault Aviation Service Bulletin Falcon 7X n° 1 33 original issue. - Goodrich Service Bulletin 80232190-24-01 original issue. - Goodrich Service Bulletin 80232191-24-01 original issue. - Goodrich Service Bulletin 80232192-24-01 original issue.EASA AD No : 2010–0073

EASA Form 112 Page 3/3 The use of later approved revisions of these docume nts is acceptable for compliance with the requirements of this AD.
Remarks : 1. If requested and appropriately substantiated, EA SA can approve Alternative Methods of Compliance for this AD. 2. This AD was posted on 11 March 2010 as PAD 10-02 2 for consultation until 08 April 2010. No comments were received duri ng the consultation period. 3. Enquiries regarding this AD should be referred t o the Airworthiness Directives, Safety Management & Research Section, C ertification Directorate, EASA. E-mail ADs@easa.europa.eu

. 4. For any question concerning the technical conten t of the requirements in this AD, please contact your Dassault Falcon Techni cal Assistance:

• For Europe, Middle East and Africa based operators : Hot Line: (33) 1 47 11 37 37 / Fax: (33) 1 47 11 89 49

• For USA, Canada and Mexico based operators: Help Desk: (1) 800-2FALCON (2325266) / Fax: (1) 201 541 4740

• All other areas: Help Desk: (1) 201 541 4747 / Fax: (1) 201 541 4740