## Airworthiness Directive Luftfahrt-Bundesamt
Airworthiness Directive Section Hermann-Blenk-Str. 26 38108 Braunschweig Federal Republic of Germany

Enquiries regarding this Airworthiness Directive should be referred to Mr. Olaf Schneider, Airworthiness Directive Section at the above address, fax-no. 0049 531/2355-720. Please note, that in case of any difficulty, reference should be made to the German issue! 

## Eurocopter Deutschland

Affected: Kind of aeronautical product: Manufacturer: Type: Models affected: Serial numbers affected: German Type Certificate No.: Helicopter Eurocopter Deutschland, Ottobrunn, Germany EC 135 EC 135 T1 all 3061

Subject: Power Plant EC 135 T1 - automatic engine control - synchronisation procedure for fuel control components for sustaining the automatic engine control

Reason: In the past, a few cases occurred on EC135 T1 helicopters, by which a FADEC FAIL caution indication was displayed, caused by a discrepancy in the parameters which were generated within the fuel main metering unit and transmitted to the FADEC. This discrepancy lead, on appearance of the FADEC FAIL caution indication, to „freezing“ of the fuel main metering valve at its momentary position, resulting in loss of the automatic engine control in the affected system. Despite measures undertaken by Turbomeca for elimination of the problem (software improvements TU19C, TU23C and TU45C), a few further FADEC FAIL cases have occurred on EC 135 T1 helicopters, for which no explanation hat yet been found and by which a discrepancy in parameters at the cause cannot be ruled out. With this Airworthiness Directive a synchronisation procedure for pilots, which was already used in the past, is being introduced, which prevents the parameter discrepancy arising and thus sustains the automatic engine control.

Action: Insert pages into the Flight Manual in accordance with the instructions of the referenced Alert Service Bulletin.

Compliance: Before the next flight.

Technical publication of the manufacturer: Eurocopter Deutschland Alert Service Bulletin No. EC135-71A-024 dated June 08, 2002 which becomes herewith part of this AD and must be obtained from Messrs.:

Eurocopter Deutschland GmbH Technical Publication Department 86607 Donauwörth Federal Republic of Germany

Phone: + 49 (0) 906 71-0 Fax: + 49 (0) 906 71-4112

E-Mail: rolf.stoeger@eurocopter.com

Holders of affected aircraft registered in Germany have to observe the following: Action has to be accomplished by the owner of the aircraft or an approved service station and to be checked and entered in the log book by a licensed inspector.

As a result of the a.m. deficiencies, the airworthiness of the aircraft is affected to such an extent that after the expiry of the a.m. dates the aircraft may be operated only after proper accomplishment of the prescribed actions. In the interest of aviation safety outweighing the interest of the receiver in a postponement of the prescribed actions, the immediate compliance with this AD is to be directed. 

## 2002-333

Effective Date: September 16, 2002An appeal to this notice may be raised within a period of one month following notification. Appeals are to be raised

with the Luftfahrt-Bundesamt, Hermann-Blenk-Str. 26, 38108 Braunschweig, in writing or for the purpose of drawing up minutes.