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 

ARRIUS 2 No. 319 73 2825

Subject: Visual inspection of adjusted 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: 

- Changes to the conditions of application, for engines in service, at the 

operator's site, at a Service Center or at a Maintenance Center. 

- Inspection criteria added for the sleeve assembly.

 SB_319_73_2825_EN - G <January 24, 2013> - 1 / 12
MANDATORY SERVICE BULLETIN 

1. Compliance 

SB effectivity date * FEBRUARY 2005

 Date on which this Mandatory SB becomes effective and must systematically be complied 

with, according to the conditions of application. 

If these resources are available any earlier, the Mandatory SB may, as an exception, be 

applied prior to the effectivity date. 

CAUTION: FAILURE TO APPLY THIS MANDATORY SB MAY LEAD TO AN UNCOMMANDED 

IN-FLIGHT ENGINE SHUT-DOWN.

A. Application 

Application of this Mandatory Service Bulletin (SB) is considered mandatory as a result of a 

technical requirement which might affect flight safety of engines in service. It may be done as 

defined by the effectivity code given in the table below. 

Validity Code

ARRIUS 2B1 - 2B1A (post TU 45C) - 2B2 

ARRIUS 2K1 - 2K2 

ARRIUS 2G1 

1-A 

Note: For post TU 45C ARRIUS 2 B1A engines, the engine variant marked on the 

identification plate is ARRIUS 2B1A_1. The engine type remains ARRIUS 2 B1A.

Conditions of application for engines in service 

(1) Application at the operator's site, at a TURBOMECA-approved Service Center or at 

a TURBOMECA-approved Maintenance Center 

The conditions of application of this Mandatory SB are given in the table below:

Conditions of application Maintenance task 

to be performed

Deadline for application(2)

If the HMU has logged 

more than 500 hours 

since the last application 

of SB No. 319 73 2825

Within 200 hours of 

receiving this SB and then

every 500 HMU operating

hours(1)

SB No. 319 73 2825 

already applied to the 

HMU

If the HMU has logged 

less than 500 hours 

since the last application 

of SB No. 319 73 2825. 

Every 500 HMU operating

hours(1)

The HMU has operated 

for less than 200 hours 

since new (TSN) or 

since overhaul (TSO)

At 200 hours (HMU TSN or 

TSO) and then every 500

HMU operating hours(1)

SB No. 319 73 2825 

never applied to the 

HMU

The HMU has operated 

for more than 200 hours 

since new (TSN) or 

since overhaul (TSO)

Visual inspection and 

cleaning of adjusted 

HMU drive-link splines 

and sending of the 

results

Within 50 hours of receiving 

this SB and then every 500

HMU operating hours(1)

 SB_319_73_2825_EN - G <January 24, 2013> - 2 / 12
MANDATORY SERVICE BULLETIN 

(1): This 500-hour frequency must be considered as a maximum. An inspection deadline 

can be reduced to synchronize this inspection with an engine/airframe inspection.

(2): a 10% tolerance can be applied to the defined inspection frequencies. This tolerance 

cannot be cumulated during two successive inspection deadlines.

(2) Application at a TURBOMECA-approved Repair Center 

Upon first return to an approved Repair Center, regardless of the reason for return. 

B. Purpose 

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) Application 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) Application 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 ARRIUS 2 Overhaul Manual and Component Maintenance Manual.

H. Weight and balance 

Not applicable. 

I. References 

(1) ARRIUS 2 B1 Maintenance Manual .......................................... Ref. X 319 L5 301 2. 

(2) ARRIUS 2 B1A Maintenance Manual........................................ Ref. X 319 L5 451 2. 

(3) ARRIUS 2B2 Maintenance Manual ........................................... Ref. X 319 N3 451 2. 

(4) ARRIUS 2K1 Maintenance Manual ........................................... Ref. X 319 N1 300 2. 

(5) ARRIUS 2K2 Maintenance Manual ........................................... Ref. X 319 N0 452 2. 

(6) ARRIUS 2G1 Maintenance Manual........................................... Ref. X 319 R4 450 2. 

(7) ARRIUS 2B1 - 2B1A Overhaul Manual ..................................... Ref. X 319 L5 500 2. 

(8) ARRIUS 2B2 Overhaul Manual ................................................. Ref. X 319 N3 500 2. 

 SB_319_73_2825_EN - G <January 24, 2013> - 3 / 12
MANDATORY SERVICE BULLETIN 

(9) ARRIUS 2K1 Overhaul Manual ................................................. Ref. X 319 N1 500 2. 

(10) ARRIUS 2K2 Overhaul Manual ................................................. Ref. X 319 N0 500 2. 

(11) ARRIUS 2G1 Overhaul Manual................................................. Ref. X 319 R4 500 2. 

(12) ARRIUS 2B1 Component Maintenance Manual........................ Ref. 73-23-02 2. 

(13) ARRIUS 2B1 - 2B1A Component Maintenance Manual............ Ref. 73-23-07 2. 

(14) ARRIUS 2B2 Component Maintenance Manual........................ Ref. 73-23-11 2. 

(15) ARRIUS 2K1 Component Maintenance Manual........................ Ref. 73-23-12 2. 

(16) ARRIUS 2K2 Component Maintenance Manual........................ Ref. 73-23-15 2. 

(17) ARRIUS 2G1 Component Maintenance Manual ...................... Ref. 73-23-19. 

J. Other publications concerned 

(1) ARRIUS 2B1 Spare Parts Catalog ............................................ Ref. X 319 L5 701 2. 

(2) ARRIUS 2B1A Spare Parts Catalog.......................................... Ref. X 319 L5 702 2. 

(3) ARRIUS 2B2 Spare Parts Catalog ............................................ Ref. X 319 N3 700 2. 

(4) ARRIUS 2K1 Spare Parts Catalog ............................................ Ref. X 319 N1 700 2. 

(5) ARRIUS 2K2 Spare Parts Catalog ............................................ Ref. X 319 N0 700 2. 

(6) ARRIUS 2G1 Spare Parts Catalog............................................ Ref. X 319 R4 700 2. 

(7) ARRIUS 2B1 Illustrated Parts Catalog ...................................... Ref. X 319 L5 601 2. 

(8) ARRIUS 2B1A Illustrated Parts Catalog.................................... Ref. X 319 L5 602 2. 

(9) ARRIUS 2B2 Illustrated Parts Catalog ...................................... Ref. X 319 N3 600 2. 

(10) ARRIUS 2K1 Illustrated Parts Catalog ...................................... Ref. X 319 N1 600 2. 

(11) ARRIUS 2K2 Illustrated Parts Catalog ...................................... Ref. X 319 N0 600 2. 

(12) ARRIUS 2G1 Illustrated Parts Catalog..................................... Ref. X 319 R4 600 2. 

 SB_319_73_2825_EN - G <January 24, 2013> - 4 / 12
MANDATORY SERVICE BULLETIN 

2. Instructions to be incorporated 

A. Implementation 

This inspection may be performed without removing the engine. 

(1) Application at the operator's site, at a TURBOMECA-approved Service Center or at 

a TURBOMECA-approved Maintenance Center 

Visually inspect HP pump drive gear shaft splines, clean and inspect sleeve assembly 

splines.

(2) At a TURBOMECA-approved Repair Center 

Visually inspect HP pump drive gear shaft splines, clean and inspect sleeve assembly 

splines.

B. Operating instructions (see Figures)

(1) Application 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 ARRIUS 2 Maintenance Manual, 

task 73-23-00-900-801.

Nota : For post TU 38A engines, do not remove flanged union.

(b) Remove sleeve assembly: refer to relevant ARRIUS 2 Maintenance Manual, 

task 73-23-00-200-801.

(c) Clean and inspect removed sleeve assembly: refer to relevant ARRIUS 2 

Maintenance Manual, tasks 73-23-00-200-801 and 70-01-00-940-801 (“cleaning” 

paragraph).

Additional inspection: in addition to inspections of task 73-23-00-200-801, 

make sure there are no deposits (whatever the type: grease or other) at the 

bottom of sleeve assembly female splines. 

 If deposits are found at the bottom of sleeve assembly female splines, 

replace sleeve assembly, and install new retaining ring on HP pump drive 

gear shaft and on sleeve assembly. 

(d) Inspect adjusted HMU: refer to relevant ARRIUS 2 Maintenance Manual, 

task 73-23-00-200-801.

(e) Record equipment inspection results in appendix 2 of this Mandatory SB. 

(f) Install sleeve assembly on HP pump drive gear shaft: refer to relevant ARRIUS 2 

Maintenance Manual, task 73-23-00-200-801.

(g) Install adjusted HMU: refer to relevant ARRIUS 2 Maintenance Manual, 

task 73-23-00-900-801.

(2) At a TURBOMECA-approved Repair Center 

Refer to the relevant ARRIUS 2 Overhaul Manual and Component Maintenance Manual.

C. Reconditioning and checks 

(1) Application 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 ARRIUS 2 Maintenance Manual, 

task 71-02-13-280-801.

(2) At a TURBOMECA-approved Repair Center 

Refer to the relevant ARRIUS 2 Overhaul Manual and Component Maintenance Manual.

 SB_319_73_2825_EN - G <January 24, 2013> - 5 / 12
MANDATORY SERVICE BULLETIN 

D. Identification 

(1) Application at the operator's site, at a TURBOMECA-approved Service Center or at 

a TURBOMECA-approved Maintenance Center 

(a) If adjusted HMU was not replaced

1 Complete the current or unique engine log book as follows: 

- Record the application of Mandatory SB No. 319 73 2825 on the log card of 

the adjusted HMU.

2 Notify TURBOMECA that Mandatory SB No. 319 73 2825 has been applied by 

returning the fully completed compliance certificate (Appendix 2 of this 

Mandatory SB). 

(b) If adjusted HMU was replaced:

1 Complete the following sections in the current or unique engine log book: 

- Update the log card of the removed adjusted HMU and the log card of the 

installed adjusted HMU.

- Section "C": Record the replacement of the adjusted HMU and integrate the 

log card of the installed adjusted HMU.

2 Return the removed adjusted HMU to a TURBOMECA-approved Repair Center. 

3 Notify TURBOMECA that the adjusted HMU has been replaced by returning the 

fully completed compliance certificate (Appendix 1 of this Mandatory SB). 

(2) At a TURBOMECA-approved Repair Center 

(a) Complete the current or unique engine log book as follows:

- Record the application of Mandatory SB No. 319 73 2825 on the log card of the 

adjusted HMU.

(b) Notify TURBOMECA that Mandatory SB No. 319 73 2825 has been applied by 

returning the fully completed compliance certificate (Appendix 2 of this Mandatory 

SB).

E. Routine maintenance 

Not applicable. 

 SB_319_73_2825_EN - G <January 24, 2013> - 6 / 12
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 

New 

Part Number Key Qty Description Price Old Part Number Key Qty

9 745 00 800 5 B 1 Retaining ring of sleeve 

assembly * 

0 319 91 134 0 B 1 Retaining ring of HP pump 

drive gear shaft * 

0 319 91 732 0 B 1 Sleeve assembly * 

* 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. 

 SB_319_73_2825_EN - G <January 24, 2013> - 7 / 12
MANDATORY SERVICE BULLETIN 

FIGURE 

Manchon complet 

Sleeve assembly 

Arbre pignon menant de la 

pompe HP 

Drive gear shaft of the 

HP pump 

 SB_319_73_2825_EN - G <January 24, 2013> - 8 / 12
MANDATORY SERVICE BULLETIN 

Objet : Attestation de remplacement de l'ensemble pompe/doseur 

réglé.

Subject: Compliance certificate for 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 

Utilisateur

Customer 

N° Appareil

Aircraft S/N 

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

Moteur 

Engine 

Ensemble pompe/ 

doseur réglé déposé 

Removed adjusted HMU 

Ensemble pompe/ 

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 pompe/doseur réglé identifié ci-dessus a été installé selon les directives de 

ce SB Impératif. 

I certify that the above-mentioned adjusted HMU has been installed 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 : 

 SB_319_73_2825_EN - G <January 24, 2013> - 9 / 12
MANDATORY SERVICE BULLETIN 

Objet : Attestation d’application du SB Impératif n° 319 73 2825 et 

résultats d’inspection

Subject: Mandatory SB No. 319 73 2825 compliance certificate and 

inspection results 

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 

Module 01 

Module 01 

Ensemble pompe/ 

doseur contrôlé 

Inspected adjusted 

HMU

 

Heures depuis pose de l’ensemble 

pompes HP/BP sur le module 01 

Time since installation of HMU on 

module 01 

* 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) 

Type et localisation des endommagements / Type and location of damage 

1. Cannelures de l’arbre pignon menant de la pompe HP / HP pump drive gear shaft 

splines

 SB_319_73_2825_EN - G <January 24, 2013> - 10 / 12
MANDATORY SERVICE BULLETIN 

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

Résultats du contrôle (cocher la case correspondante) 

Inspection result: check the corresponding box

Conforme 

Compliant

Non conforme

Not compliant

Corrosion / Corroded

Impact / Impact

Ecaillage / Scalling

Arrachement / Stripped

Usure de frottement perceptible au toucher / Fretting perceptible 

by touch

Autre / other

Si non conforme, préciser la non-conformité 

If not compliant, describe the non-compliance 

2. Cannelures mâle du manchon complet / Sleeve assembly male splines

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

Résultats du contrôle (cocher la case correspondante) 

Inspection result: check the corresponding box

Conforme 

Compliant

Non conforme

Not compliant

Corrosion / Corroded

Impact / Impact

Ecaillage / Scalling

Arrachement / Stripped

Usure de frottement perceptible au toucher / Fretting perceptible 

by touch

Autre / other 

Si non conforme, préciser la non-conformité 

If not compliant, describe the non-compliance 

 SB_319_73_2825_EN - G <January 24, 2013> - 11 / 12
MANDATORY SERVICE BULLETIN 

3. Cannelures femelle du manchon complet / Sleeve assembly female splines

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

Résultats du contrôle (cocher la case correspondante) 

Inspection result: check the corresponding box

Conforme 

Compliant

Non conforme

Not compliant

Corrosion / Corroded

Impact / Impact

Ecaillage / Scalling

Arrachement / Stripped

Résidu (tous types) en fond de cannelures / Deposits (all types) 

on splines bottom

Autre / other

Si non conforme, préciser la non-conformité 

If not compliant, describe the non-compliance 

Opération effectuée par : 

Work performed by:

Je certifie que l'ensemble pompe/doseur réglé identifié ci-dessus a été inspecté selon les directives 

de ce SB Impératif. 

I certify that the above-mentioned adjusted HMU has been inspected 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 : 

 SB_319_73_2825_EN - G <January 24, 2013> - 12 / 12