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 by EASA, acting in accordance with 

Regulation (EC) No 216/2008 on behalf of the European 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 ensured by accomplishing any applicable ADs. Consequently, no person may 

operate an aircraft to which an AD applies, except in accordance with the requirements of that AD unless otherwise specified by the 

Agency [EC 2042/2003 Annex I, Part M.A.303] or agreed 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 Diodes – 

Inspection/Replacement 

Manufacturer(s): Dassault Aviation 

Applicability: Falcon 7X aeroplanes, all serial numbers except those on which modification 

Dassault Aviation M724 is embodied. 

Reason: Several in service events related to various 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 Distribution Control Units 

(PDCU) cards or Generator Control Unit (GCU) cards in the Primary Power 

Distribution Boxes (PPDB). Due to such TVS diode failure mode, operation of 

some electrical circuits is degraded and some control signals are set at 

unexpected levels. Further analysis indicated that combination of a TVS diode 

failure with other systems failures could significantly reduce flight safety. 

To prevent and correct this condition, some Airplane Flight Manual (AFM) 

procedures have been modified to reduce the time of exposure to further 

failures whenever a TVS diode failure occurs. Additionally, 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 tolerances. The criteria for 

PDCU or GCU card replacement in case of detection of faulty components 

have been identified. 

This AD requires the accomplishment of the revised AFM procedures, the 

testing and, as necessary, the replacement of the affected PDCU and GCU 
EASA AD No : 2010–0073 

EASA Form 112 Page 2/3 

cards. 

Meanwhile, Dassault Aviation is developing a modification (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 previously: 

(1) After the effective date of this AD, amend the F7X AFM sub-section 

abnormal procedures and the Quick Reference Handbook 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 nearest 

suitable airport 

o Upon display of ELEC:RH ESS PWR LO and ELEC:RH ESS 

NO PWR (Abnormal procedure 3-190-45), land at nearest 

suitable airport 

o Upon display of HYD:BACKUP PUMP HI TEMP (Abnormal 

procedure 3-250-15), set off the pump and if the backup pump 

is still rotating (green) in hydraulic synoptic, descend to a safe 

altitude or below 15,000 ft 

Caution: These temporary amendments take precedence over the same 

procedures displayed through the Electronic Check List (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 demonstrated 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 the 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 replace the affected PDCU 

and GCU cards in accordance with the instructions of Dassault Aviation 

SB n°133. 

(4) Accomplishment of Goodrich Service Bulletins 80232190-24-01, 

80232191-24-01 and 80232192-24-01 is also acceptable 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 documents is acceptable for 

compliance with the requirements of this AD. 

Remarks : 1. If requested and appropriately substantiated, EASA can approve 

Alternative Methods of Compliance for this AD. 

2. This AD was posted on 11 March 2010 as PAD 10-022 for consultation 

until 08 April 2010. No comments were received during the consultation 

period. 

3. Enquiries regarding this AD should be referred to the Airworthiness 

Directives, Safety Management & Research Section, Certification 

Directorate, EASA. E-mail ADs@easa.europa.eu. 

4. For any question concerning the technical content of the requirements in 

this AD, please contact your Dassault Falcon Technical 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