40220 Tarnos - France Tel. +33 (0)5 59 74 40 00 - Telex 570 042 - Fax +33 (0)5 59 74 45 15



# MANDATORY SERVICE BULLETIN

ARRIEL 2 No. 292 73 2812

Subject: Visual inspection of adjusted Hydromechanical Metering Unit (HMU) drive-link splines.

The technical information contained in this document has been approved under the Design Organization Approval No. EASA.21J.070.



## Version: G

Reason for update: Reinforcement of the compliance code and conditions.



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# MANDATORY SERVICE BULLETIN

1. Compliance

SB effectivity date * JULY 2003

* Date on which this Mandatory SB becomes effective and must systematically be complied with,

according to the conditions of application. This date corresponds to when all resources needed to perform the procedure (parts, tools, documentation, etc.) will be available. If these resources are available any earlier, the SB may, as an exception, be applied prior to the effectivity date.

CAUTION: FAILURE TO APPLY THIS MANDATORY SERVICE BULLETIN MAY LEAD TO AN UNCOMMANDED IN-FLIGHT ENGINE SHUT-DOWN WHICH, ON A SINGLE-ENGINE HELICOPTER, LEADS TO AN EMERGENCY AUTOROTATION LANDING. 

### A. Compliance
Application of this Mandatory Service Bulletin (SB) is considered mandatory as a result of a technical requirement which might affect flight safety. It may be done immediately or to accommodate an existing schedule.
Validity Code

ARRIEL 2B - 2B1 - 2B1A - 2B1B 1-A

Note: variants 2C, 2C1, 2C2, 2S1 and 2S2 are addressed in Mandatory SB No. 292 73 2822. Conditions of application for engines in service (1) At the operator's site, at a TURBOMECA-approved Service Center or at a TURBOMECA-approved Maintenance Center The purpose of this Mandatory SB is to inspect HMU splines after 500 operating hours of HMU/current M01 assembly. If the result is compliant after 500 operating hours and providing that HMU/current M01 assembly remains unchanged, it will never again be necessary to inspect splines. A new inspection will only be performed (even if the SB was already applied) in the following cases:

 HMU is removed from current M01 and installed on another M01 or

 M01 is replaced or

 HMU is repaired / overhauled (given that the splines can be replaced during repair/level 4 overhaul). To determine the operating hours logged by the HMU/current M01 assembly:

 Check HMU log card to see the date that the HMU began operating on this engine.

 On engine log book, check that M01 was not replaced since this date.

 Check HMU log card to know if it was overhauled/repaired since it operated on current M01.

 Determine the total operating hour s logged by the M01/HMU assembly:

o since HMU first operated on current M01 or

o since HMU repair/overhaul. The compliance conditions of this Mandatory SB and the associated deadlines are shown in the table on the following page.



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# MANDATORY SERVICE BULLETIN

Note : In accordance with Maintenance Manual, task 73-23-00-900-801, visual inspection of drive-link splines must be performed each time the adjusted HMU is removed/installed. (2) At a TURBOMECA-approved Repair Center Application before delivery Is it installed on the engine?

HMU

How many operating hours* ?

> 500 operating hours* Less than 500 operating hours *

Task(s) to be performed:

Submit compliance certificate for previous inspection (If available and not already returned) Task(s) to be performed:

Visual inspection of adjust ed HMU drive-link splines And Submission of results according to appendices of this Mandatory SB

Deadline:

Within 25 operating hours of receiving version G of this Mandatory SB Deadline:

Between 500 and 525

operating hours * Was the SB (all versions) applied after HMU logged 500 operating hours*? No

Yes

Deadline:

Upon receiving version G of this Mandatory SB Perform inspection before installation according to task 73-23-00-900-801 of the

Maintenance Manual (no need to return results according to appendices of this Mandatory SB) No Yes

Once installed on M01 * Operating hours logged by the HMU/ current M01 assembly. Note: If HMU was repaired/overhauled since first operating on current module M01, operating hours since repair/ overhaul must be taken into account.



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# MANDATORY SERVICE BULLETIN

B. Purpose
CAUTION: FAILURE TO APPLY THIS MANDATORY SERVICE BULLETIN MAY LEAD TO AN UNCOMMANDED IN-FLIGHT ENGINE SHUT-DOWN WHICH, ON A SINGLE-ENGINE HELICOPTER, LEADS TO AN EMERGENCY AUTOROTATION LANDING. 

### To avoid an uncommanded in-flight engine shut-down caused by damage to the adjusted HMU drive-link splines. 

### C. Description Visual inspection to check the condition of the HP pump drive gear shaft splines, cleaning and inspection of the sleeve assembly splines. 

### D. Approval The technical information contained in this document has been approved under the Design Organization Approval No. EASA.21J.070. This Mandatory SB is subject to an Airworthiness Directive. 

### E. Manpower (1) At the operator's site, at a TURBOMECA-approved Service Center or at a TURBOMECA-approved Maintenance Center (a) Personnel: 1 mechanic. (b) Time required: 1 man-hour. (2) At a TURBOMECA-approved Repair Center (a) Personnel of approved Repair Center. (b) Time determined by the Repair Center as being appropriate for this level of intervention.


### F. Material Refer to paragraph 3. 

### G. Tooling (1) At the operator's site, at a TURBOMECA-approved Service Center or at a TURBOMECA-approved Maintenance Center Mechanic's standard tooling. (2) At a TURBOMECA-approved Repair Center Refer to the relevant ARRIEL 2 Overhaul Manual or Component Maintenance Manual. 

### H. Weight and balance Not applicable.


### I. References (1) ARRIEL 2B Maintenance Manual................................................ Ref. X 292 M5 450 2. (2) ARRIEL 2B1 Maintenance Manual.............................................. Ref. X 292 N5 450 2. (3) ARRIEL 2B1A Maintenance Manual ........................................... Ref. X 292 P4 450 2. (4) ARRIEL 2B Overhaul Manual...................................................... Ref. X 292 M5 500 2. (5) ARRIEL 2B1 - 2B1A Overhaul Manual........................................ Ref. X 292 N5 500 2. (6) ARRIEL 2B Component Maintenance Manual ............................ Ref. X 73 23 03 2. (7) ARRIEL 2B1 - 2B1A Component Maintenance Manual .............. Ref. X 73 23 05 2. (8) Relevant Helicopter Maintenance Manual.



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# MANDATORY SERVICE BULLETIN

J. Other publications concerned (1) ARRIEL 2B Spare Parts Catalog........................................... Ref. X 292 M5 700 2. (2) ARRIEL 2B1 Spare Parts Catalog......................................... Ref. X 292 N5 700 2. (3) ARRIEL 2B1A Spare Parts Catalog ...................................... Ref. X 292 P4 700 2. (4) ARRIEL 2B Illustrated Parts Catalog..................................... Ref. X 292 M5 600 2. (5) ARRIEL 2B1 Illustrated Parts Catalog................................... Ref. X 292 N5 600 2. (6) ARRIEL 2B1A Illustrated Parts Catalog ................................ Ref. X 292 P4 600 2.



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# MANDATORY SERVICE BULLETIN

2. Instructions to be incorporated
A. Implementation This inspection may be performed without removing the engine from the helicopter. (1) At the operator's site, at a TURBOMECA-approved Service Center or at a TURBOMECA-approved Maintenance Center Remove adjusted HMU. (2) At a TURBOMECA-approved Repair Center Remove adjusted HMU. 

### B. Operating instructions (see Figure) (1) At the operator's site, at a TURBOMECA-approved Service Center or at a TURBOMECA-approved Maintenance Center (a) Remove adjusted HMU: refer to relevant ARRIEL 2 Maintenance Manual, task 73-23-00-900-801. (b) Inspect adjusted HMU: refer to relevant ARRIEL 2 Maintenance Manual, task 73-23-00-200-802. (c) Complete Appendix 3 according to the findings. Indicate the damage type and location. (d) In case of anomaly, contact TURBOMECA to confirm removal of the HMU or sleeve assembly. Provide as many details as possible on the damage type (description and photos).
CAUTION: FAILURE TO CLIP THE SLEEVE ASSEMBLY ONTO THE DRIVE GEAR SHAFT MAY LEAD TO UNCOMMANDED IN-FLIGHT ENGINE SHUT-DOWN. 

### (e) Install adjusted HMU: refer to relevant ARRIEL 2 Maintenance Manual, task 73-23-00-900-801. (2) At a TURBOMECA-approved Repair Center Refer to the relevant ARRIEL 2 Component Maintenance Manual and complete Appendix 3 of this Mandatory SB in order to determine and specify the type and location of any found anomalies. 

### C. Reconditioning and checks (1) At the operator's site, at a TURBOMECA-approved Service Center or at a TURBOMECA-approved Maintenance Center Perform a ground run check: refer to relevant ARRIEL 2 Maintenance Manual, task 71-02-13-280-801. Note: Perform a visual leak check of adjusted HMU. (2) At a TURBOMECA-approved Repair Center Refer to relevant ARRIEL 2 Overhaul Manual, chapter 72-00-00.


### D. Identification (1) At the operator's site, at a TURBOMECA-approved Service Center or at a TURBOMECA-approved Maintenance Center (a) Complete the current or unique engine log book as follows:

- Record the application of this Mandatory SB on the log card of the inspected

adjusted HMU. (b) Notify TURBOMECA that this Mandatory SB has been applied by returning the fully completed compliance certificate (Appendix 1) and the detailed results recorded in Appendix 3 of this Mandatory SB.



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# MANDATORY SERVICE BULLETIN

(c) If replacing adjusted HMU: 1 Complete the current or unique engine log book as follows: 1.1 Section "C": record the replacement of the adjusted HMU. 1.2 Update the log card of the removed adjusted HMU and the log card of the installed adjusted HMU. 1.3 Section "E": record the replacement of the adjusted HMU. 2 Notify TURBOMECA that the adjusted HMU has been replaced by returning the fully completed compliance certificate (Appendix 2 of this Mandatory SB). (2) At a TURBOMECA-approved Repair Center (a) Complete the following sections in the unique engine log book:

- Record the application of Mandatory SB No. 292 73 2812, on the log card of the

inspected adjusted HMU. (b) Notify TURBOMECA that this Mandatory SB has been applied by returning the fully completed compliance certificate (Appendix 1).


### E. Routine maintenance Not applicable.



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# MANDATORY SERVICE BULLETIN

3. Material information

A. Basic information The parts list (provided below) required for the application of this Mandatory SB is for one engine. 

### B. List of parts Refer to relevant ARRIEL 2 Maintenance Manual for the spare parts related to installation of the adjusted HMU.

New Part Number Key Qty Name Price Old Part Number Key Qty

0 319 91 134 0 B 1 Retaining ring *

* Prices available upon request.

Key B - Part not incorporated by this inspection, but required for the inspection to be performed.



### C. Supply conditions Order supplies as needed from: your local TURBOMECA Support Center

or TURBOMECA Direction Support Ventes Opérateurs Département Commercial 40220 TARNOS France Fax No. +33 (0) 5 59 74 45 11.



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# MANDATORY SERVICE BULLETIN

Jonc Ring

Cannelures Splines Manchon complet Sleeve assembly Manchon Sleeve Jonc Ring



### FIGURE



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# MANDATORY SERVICE BULLETIN

Objet : Attestation d’application du SB Impératif n° 292 73 2812. Subject: Mandatory SB No. 292 73 2812 compliance certificate.

Important / Important notice : Après application des instructions spécifiées dans ce SB Impératif, veuillez compléter la présente attestation et la retourner par courrier ou courriel ou fax à : After application of the instructions specified in this Mandatory SB, please complete this certificate and mail or email or fax it to: TURBOMECA, Equipe Administration Base installée / Fleet data administrator Team , BP 25 40220 TARNOS – France Fax n° / No. +33 (0) 5 59 74 46 95 - Email : fleetdata@turbomeca.fr
Information concernant le matériel / Equipment information

Utilisateur Customer N° Appareil Aircraft S/N

N/S - S/N Réf. - P/N TSN * TSO * CSN* CSO*

Moteur Engine

Ensemble pompes HP/BP doseur contrôlé Inspected HMU

* TSN = Time Since New (Heures depuis neuf) TSO = Time Since Overhaul (Heures depuis RG) CSN = Cycles Since New (Cycles depuis neuf) CSO = Cycles Since Overhaul (Cycles depuis RG)

Opération effectuée par / Work performed by:
Résultats du contrôle (cocher la case correspondante) Inspection result: check the corresponding box Conforme Compliant Non conforme Not compliant
Manchon d’accouplement (cannelures mâles) Coupling sleeve (male splines)
Manchon d’accouplement (cannelures femelles) Coupling sleeve (female splines)

Cannelures mâles de l’arbre pignon menant pompe HP HP pump drive gear shaft male splines

Je certifie que l'ensemble pompes HP/BP doseur régl é identifié ci-dessus a été contrôlé selon les directives de ce SB Impératif. I certify that the above-mentioned adjusted HMU has been insp ected according to the directives given in this Mandatory SB.

Date [JJ / MMMM (en lettre) / AAAA or DD / MMMM (letter) / YYYY] Nom / Print name Fonction / Job title



### ANNEXE 1 / APPENDIX 1 Signature :



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# MANDATORY SERVICE BULLETIN

Objet : Attestation de remplacemen t de l'ensemble pompes HP/BP doseur réglé. Subject: Compliance certificate fo r replacement of adjusted HMU.

Important / Important notice : Après application des instructions spécifiées dans ce SB Impératif, veuillez compléter la présente attestation et la retourner par courrier ou courriel ou fax à : After application of the instructions specified in this Mandatory SB, please complete this certificate and mail or email or fax it to: TURBOMECA, Equipe Administration Base installée / Fleet data administrator Team , BP 25 40220 TARNOS – France Fax n° / No. +33 (0) 5 59 74 46 95 - Email : fleetdata@turbomeca.fr

Information concernant le matériel / Equipment information

Utilisateur Customer N° Appareil Aircraft S/N

N/S - S/N Réf. - P/N TSN * TSO * CSN* CSO*

Moteur Engine

Ensemble pompes HP/BP doseur réglé déposé Removed adjusted HMU

Ensemble pompes HP/BP doseur réglé posé Installed adjusted HMU

* TSN = Time Since New (Heures depuis neuf) TSO = Time Since Overhaul (Heures depuis RG) CSN = Cycles Since New (Cycles depuis neuf) CSO = Cycles Since Overhaul (Cycles depuis RG)

Opération effectuée par / Work performed by:

Je certifie que l'ensemble pompes HP/BP doseur régl é identifié ci-dessus a été installé selon les directives de ce SB Impératif. I certify that the above-mentioned adjusted HMU has been inst alled according to the directives given in this Mandatory SB.

Date [JJ / MMMM (en lettre) / AAAA or DD / MMMM (letter) / YYYY] Nom / Print name Fonction / Job title



### ANNEXE 2 / APPENDIX 2 Signature :



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# MANDATORY SERVICE BULLETIN

Objet : Feuilles de résultats du SB Impératif n° 292 73 2812. Subject: Mandatory SB No. 292 73 2812 result sheets.

Important / Important notice : Après application des instructions spécifiées dans ce SB Impératif, veuillez compléter la présente feuille de résultats et la retourne r par courrier ou courriel ou fax à : After application of the instructions specified in this Mandatory SB, please complete this result sheet and mail or email or fax it to: TURBOMECA, Equipe Administration Base installée / Fleet Data Administrator Team , BP 25
40220 TARNOS - France Fax n° / No. +33 (0) 5 59 74 46 95 - Email : fleetdata@turbomeca.fr

Information concernant le matériel / Equipment information

Utilisateur Customer N° Appareil Aircraft S/N

N/S - S/N Réf. - P/N TSN * TSO * CSN* CSO*

Moteur Engine

Module M01

Ensemble pompes HP/BP doseur réglé contrôlé Inspected adjusted HMU

Depuis que le HMU opère sur le M01 actuel Since HMU operates on current M01 Heures de fonctionnement du couple HMU / M01

Operating hours logged on current HMU / M01 assembly Depuis réparation/révision du HMU Since repair/overhaul of the HMU

* TSN = Time Since New (Heures depuis neuf) TSO = Time Since Overhaul (Heures depuis RG) CSN = Cycles Since New (Cycles depuis neuf) CSO = Cycles Since Overhaul (Cycles depuis RG)

Opération effectuée par / Work performed by:

Type et localisation des endommagements / Type and location of damage

- Cannelures de l’arbre pignon menant de la pompe HP / HP pump drive gear shaft splines

Localisation des constatations : 01 cannelures / Finding location: 01 splines



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Conforme Compliant Non conforme Not compliant Résultats du contrôle (coc her la case correspondante)
Inspection result: check the corresponding box Absence No trace Présence acceptable Acceptable trace Présence inacceptable Unacceptable trace

Corrosion / Corroded

Impact / Impact

Ecaillage / Scaling

Arrachement / Stripped

Usure de frottement perceptible au toucher / Fretting perceptible by touch

Autre / other

- Cannelures mâles du manchon complet / Sleeve assembly male splines

Localisation des constatations: 02 cannelures / Finding location: 02 splines

Conforme Compliant Non conforme Not compliant Résultats du contrôle (coc her la case correspondante)
Inspection result: check the corresponding box Absence No trace Présence acceptable Acceptable trace Présence inacceptable Unacceptable trace

Corrosion / Corroded

Impact / Impact

Ecaillage / Scaling

Arrachement / Stripped

Usure de frottement perceptible au toucher / Fretting perceptible by touch

Autre / other



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- Cannelures femelles du manchon complet / Sleeve assembly female splines

Localisation des constatations: 03 cannelures / Finding location: 03 splines

Conforme Compliant Non conforme Not compliant Résultats du contrôle (coc her la case correspondante)
Inspection result: check the corresponding box Absence No trace Présence acceptable Acceptable trace Présence inacceptable Unacceptable trace

Corrosion / Corroded

Impact / Impact

Ecaillage / Scaling

Arrachement / Stripped

Usure de frottement perceptible au toucher / Fretting perceptible by touch

Autre / other



### ANNEXE 3 / APPENDIX 3 Signature :



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