EASA AD No.: 2011-0023-E

EASA Form 111 Page 1/3 

## EASA EMERGENCY AIRWORTHINESS DIRECTIVE

AD No.: 2011-0023-E [Corrected: 10 February 2011]

Date: 09 February 2011

Note: This Emergency Airworthiness Directive (AD) i s issued by EASA, acting in accordance with Regulation (EC) No 216/2008 on behalf of the E uropean Community, its Member States and of the European third countries that participat e 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 b e ensured by accomplishing any applicable ADs. Cons equently, no person may operate an aircraft to which an AD applies, exc ept 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 :

Turboméca Type/Model designation(s) :

ARRIEL 1 series turboshaft engines

TCDS Number : EASA.E.073

Foreign AD : Not applicable

Supersedure : None



### ATA 73 Engine Fuel & Control – Low Pressure Fuel System / Ejector Assembly – Inspection / Replacement

Manufacturer(s): Turboméca S.A.

Applicability: Arriel 1E2, 1S and 1S1 turboshaft en gines, all serial numbers, on which

Turbomeca Internal Consign (IC) No. 298468 or Turbo meca Service Bulletin (SB) No. 292 73 0826 version A has been accomplishe d. These engines are known to be installed on, but not limited to, the following helicopters: Eurocopter Deutschland MBB BK117-C2 and BK117-C1, S ikorsky S-76A series and C series.

Reason: In October 2009, Turbomeca issued Turbomeca SB No.292 73 0826 version A

that instructed operators to check the effectivenes s of the bonding of the ejector jet installed on the low pressure fuel syst em between the tank and the high pressure fuel pump.
So far, TURBOMECA have been informed of three discr epancies with the reassembly of the ejector following a maintenance p rocedure performed during accomplishment of Turbomeca SB No. 292 73 0826 vers ion A. In all three cases, the discrepancies led to a “one -off” abnormal evolution of gas generator (NG) rating during engine starting. I n one of these cases, this resulted in an uncommanded in-flight engine shut-do wn, during a cruising phase at 8 000 feet.
In all three cases, the ejector was incorrectly pos itioned in the ejector assembly body.EASA AD No.: 2011-0023-E

EASA Form 111 Page 2/3 This condition, if not detected and corrected, coul d affect the ejector performance and lead to an increase in fuel system internal leakages that may cause fluctuations of NG and fuel flow disruptions. Over a given amplitude, fluctuations in fuel flow c an result in an uncommanded in-flight engine shut-down of one of the engines. I n addition, if the ejectors of both engines are incorrectly reassembled, this coul d result in an uncommanded in-flight engine shut-down of both engi nes which, on a twinengine helicopter, could ultimately lead to an emer gency autorotation landing. To address this unsafe condition, for engines on wh ich Turbomeca SB No. 292 73 0826 version A or Turbomeca IC No. 298468 ha s been accomplished, Turboméca have developed Turbomeca Mandatory Servic e Bulletin (MSB) No. A292 73 0834 version B. For the reasons described above, this AD requires i nspection for proper installation of the fuel ejector and, in case of di screpancy, replacement of the part with a serviceable part. This AD is republished to correct a typographical e rror with the related Turbomeca SBs & MSB reference number.

Effective Date: 11 February 2011

Required Action(s) and Compliance Time(s): Required as indicated, unless accomplished previous ly:

(1) Within the compliance time indicated in Table 1 of this AD, inspect the fuel ejector in the body of the fuel ejector assembly fo r proper installation in accordance with Paragraph 2.B of Turboméca MSB No. A292 73 0834 version B.

Table 1: Engine and aircraft configuration: Compliance time: SB No. 292 73 0826 version A (*) or IC No. 298468 has been accomplished to the two engines of the same aircraft AND Starting difficulties (**) have been encountered in at least one of the two engines 5 Flight Hours (FH) or 3 days after the effective date of this AD, whichever occurs first
SB No. 292 73 0826 version A (*) or IC No. 298468 has been accomplished to only one of the two engines of the same aircraft AND Starting difficulties (**) have been encountered on the related engine 20 FH or 30 days after the effective date of this AD, whichever occurs first SB No. 292 73 0826 version A (*) or IC No. 298468 has been accomplished to one or both engines of the same aircraft AND Starting difficulties (**) have not been encountered 100 FH or 90 days after the effective date of this AD, whichever occurs first

Notes for Table 1 of this AD : (*): In the engine log book, this might be recorded “SB No. 292 73 0826” or “SB No. 292 73 0826 version A”. (**): Starting difficulties is when N1 stagnation o r variation has been encountered. Applicable guidance can be found in Pa ragraph 1.A.(1) of Turboméca MSB No. A292 73 0834 version B. (2) If, during the inspection as required by paragr aph (1) of this AD, the fuel injector is found to be improperly installed, befor e next flight, replace the ejector assembly with a serviceable unit. (3) As an alternative to the actions required by pa ragraphs (1) and (2) of this AD, accomplishment of Turbomeca SB No. 292 73 0826 version B isEASA AD No.: 2011-0023-E

EASA Form 111 Page 3/3 acceptable to comply with all the requirements of t his AD, provided that the actions are taken within the same compliance ti me of this AD, as applicable. (4) After the effective date of this AD, do not ins tall on a helicopter an engine on which Turbomeca IC No. 298468 or Turbomeca SB No . 292 73 0826 version A has been accomplished, unless in complian ce with the requirements of this AD. (5) Inspections / replacements accomplished before the effective date of this AD, in accordance with the instructions of Turbomec a SB No. A292 73 0834 version A, are acceptable to comply wi th the requirements of this AD.

Ref. Publications: Turbomeca Mandatory Service Bulletin No. A292 73 08 34 version B dated 08 February 2011.

Turbomeca Service Bulletin A292 73 0826 version B d ated 4 February 2011. 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. The safety assessment has requested not to imple ment the full consultation process and an immediate publication a nd notification. 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: Turboméca, S.A., ARRIEL 1 Customer Support, 40220 T ARNOS, FRANCE. Fax: +33 5 59 74 45 15 or contact your near est technical representative at www.turbomeca-support.com