40220 Tarnos - France

Tel. +33 (0)5 59 74 40 00

Fax +33 (0)5 59 74 45 15

SERVICE BULLETIN

Applicable variants: ASTAZOU XIV B-H-M1 post mod. AB 173 or AB 208

ASTAZOU XIV No. 283 72 0811

Subject: Rotating assembly.

Reinforced inspection of 3rd stage turbine wheels P/N 0265257000 

or 0265257060.

The technical information contained in this document is approved under the Authority 

of Design Organization Approval No. EASA.21J.070.

Date on which this SB becomes effective and must systematically be complied with, according to the 

conditions of application.

AS SOON AS THIS SB IS RECEIVED

If the resources needed to perform the procedure (parts, tools, documentation, etc.) are available any 

earlier, this SB may, as an exception, be applied prior to the effectivity date.

Version: A

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SERVICE BULLETIN

Applicable variants: ASTAZOU XIV B-H-M1 post mod. AB 173 or AB 208 §1 - 1/1

1. GENERAL

1.1. Purpose

Detect the presence of any cracks between the balancing plugs on the front face of the 3rd stage turbine wheel.

1.2. Reason

During the overhaul of an ASTAZOU XIV engine, a crack located on the front face of the 3rd stage turbine wheel 

was detected between two balancing plugs. The cause of the damage is probably linked to a geometric 

singularity, caused by the transformation operation aimed at introducing expansion slots between the blades 

(modification AB173).

1.3. Description 

This SB consists of inspecting the front face of the 3rd stage turbine wheel in the area of the balancing plugs.

1.4. Approval

The technical information contained in this document has been approved under the Design Organization 

Approval No. EASA.21J.070.

1.5. Conditions of application

The conditions of application of this SB are defined respectively in:

- Chapter §2 regarding application at the operator’s site or by a qualified Maintenance Center for level 1, 

2.

- Chapter §3 regarding application by a qualified Maintenance Center for level 3.

- Chapter §4 regarding application at a TURBOMECA-approved Repair Center.

1.6. Update history

Not applicable.

END of section §1

"General"

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SERVICE BULLETIN

Applicable variants: ASTAZOU XIV B-H-M1 post mod. AB 173 or AB 208 §2 - 1/1

2. APPLICATION AT THE OPERATOR’S SITE OR BY A QUALIFIED MAINTENANCE CENTER 

FOR LEVEL 1, 2

Not applicable.

END of section §2

"Application at the operator’s site or by a qualified Maintenance Center for level 1, 2 "

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SERVICE BULLETIN

Applicable variants: ASTAZOU XIV B-H-M1 post mod. AB 173 or AB 208 §3 - 1/1

3. APPLICATION BY A MAINTENANCE CENTER QUALIFIED FOR LEVEL 3

Not applicable.

END of section §3

“Application by a qualified Maintenance Center for level 3”

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SERVICE BULLETIN

Applicable variants: ASTAZOU XIV B-H-M1 post mod. AB 173 or AB 208 §4 - 1/4

4. APPLICATION AT A TURBOMECA-APPROVED REPAIR CENTER

4.1. Actions to be performed

Remove the 3rd stage turbine wheel to inspect the profile of the rim on the front face, at the level of the 

balancing plugs.

4.2. Effectivity and application times

ENGINE / VARIANT CODE CONDITIONS OF APPLICATION 

FOR ENGINES IN SERVICE

Post AB 173 or 

post AB 208 ASTAZOU XIV B-H-M1 2-4

Application upon first return to an approved Repair Center, 

regardless of the reason for return.

This SB must be applied with strict conformity to the conditions of application as specified by the manufacturer 

according to the effectivity code given in the table above.

4.3. Conditions of application for engines in service

This SB concerns AB 173 modified or AB 208 modified ASTAZOU XIV B-H-M1 engines having 3rd stage turbine 

wheel whose Part Number (section D of the engine log book) is:

- 0 265 25 700 0, whatever the serial number, or

- 0 265 25 706 0, whatever the serial number.

4.4. Accomplishment Instructions

4.4.1. Implementation

Applicable for all engines unless this SB has already been applied.

4.4.2. Procedure

4.4.2.1.Remove the 3rd stage turbine wheel: refer to Overhaul Manual, chapter 72-50-20.

4.4.2.2.Perform cleaning of the 3rd stage turbine wheel: refer to Overhaul Manual, chapter 72-50-20.

4.4.2.3.Perform a visual inspection of the front and rear faces of the 3rd stage turbine wheel: 

- If there is no groove between the spotfaces on the leading edge side and trailing edge side 

(Figure 1):

 No further action is required

No groove Presence of a groove

FIGURE 1

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SERVICE BULLETIN

Applicable variants: ASTAZOU XIV B-H-M1 post mod. AB 173 or AB 208 §4 - 2/4

- If there is a groove between the spotfaces on the leading edge side or trailing edge side 

(Figure 1):

 If the radius under the platform is machined: scrap the turbine wheel (see Figure 2)

 If the radius is not machined:

o Rework the face according to Overhaul Manual chapter 72-50-20 if the thickness 

value of the rim (J) > 22.60 mm, via application of SL-0559-01. ThisSL is only 

applicable once per turbine wheel.

o Check that the groove is entirely eliminated using a circumference, and that the 

thickness of the rim is over 22.30 mm.

Thickness value of rim (J) :

• J ≥ 22.60 mm, rework can be performed

• J < 22.60 mm, rework cannot be performed

• J < 22.30 mm, turbine wheel to be scrapped

Area 1: Removed balancing bead

Area 2: Groove to be characterized

Area 3: Radius under platform

Depth (P) of groove 

> 0 mm and no machining 

at radius under platform

 Rework of turbine wheel 

if thickness of rim is 

sufficient and no SL01 

marking is found.

Alteration of radius under 

platform

 Turbine wheel to be 

scrapped

Absence of groove and no 

machining at radius under 

platform

 Turbine wheel 

acceptable as is

FIGURE 2

 Fill in Appendix 4.1 and send it to the address provided.

Direction of measurement

Direction of measurement

Direction of measurement

Direction of measurement

Area 2

Area 1

Area 3

P

Alteration 

of radius

Area 1 Area 2 Area 3

J

Absence

of groove

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SERVICE BULLETIN

Applicable variants: ASTAZOU XIV B-H-M1 post mod. AB 173 or AB 208 §4 - 3/4

4.4.3. Reconditioning and checks 

Refer to the ASTAZOU XIV Overhaul Manual. 

4.5. Information related to parts 

4.5.1. List of supplies 

Refer to the ASTAZOU XIV Overhaul Manual. 

4.5.2. Supply conditions 

Your local TURBOMECA Support Center 

or

TURBOMECA 

Support and Services Division 

Commercial Department 

40220 TARNOS - France 

Fax No. +33 (0) 5 59 74 45 11. 

4.6. Manpower 

 Personnel of approved Repair Center 

 Time determined by the Repair Center as being appropriate for this level of intervention. 

4.7. Tooling and/or products 

Refer to the ASTAZOU XIV Overhaul Manual. 

4.8. Weight and balance 

Not applicable. 

4.9. Publication references 

Document Engine Reference 

Overhaul Manual (OM) ASTAZOU XIV B-F-H-M-M1

Illustrated Parts Catalog (IPC) ASTAZOU XIV B-F-H 283 01 932

ASTAZOU XIV M-M1 X 283 98 600 2

Service Bulletin Modification AB 173 No. 72 283 0091

Service Bulletin Modification AB 208 No. 283 72 0117

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X 283 72 500 2
SERVICE BULLETIN

Applicable variants: ASTAZOU XIV B-H-M1 post mod. AB 173 or AB 208 §4 - 4/4

Objet : Attestation d’application du SB n° 283 72 0811.

Subject: SB No. 283 72 0811 compliance certificate.

Important / Important notice : 

Après application des instructions spécifiées dans ce SB, veuillez compléter la présente attestation et la 

retourner par courrier ou courriel à :

After application of the instructions specified in this 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

Roue de turbine 

3

ème étage

3

rd stage turbine 

w heel

* TSN = Time Since New (Heures depuis neuf) TSO = Time Since Ov erhaul (Heures depuis RG)

CSN = Cycles Since New (Cycles depuis neuf) CSO = Cycles Since Ov erhaul (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

Si non conforme, préciser la non 

conformité

If not compliant, describe the nonconformity

Je certifie que le moteur identifiée ci-dessus a été contrôlée selon les directives de ce SB.

I certify that the above-mentioned engine has been checked according to the directives given in this Mandatory 

SB.

Date [JJ/MMMM (en lettre)/AAAA 

ou/or DD/MMMM (letter)/YYYY]

Nom / Name Fonction / Job title

ANNEXE 4.1 / APPENDIX 4.1

Signature :

END of section §4

“Application by a TURBOMECA-approved Repair Center”

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