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EMERGENCY 

ALERT SERVICE BULLETIN 

SUBJECT: FUSELAGE 

Check of the tail boom / Fenestron junction frame

AIRCRAFT 

CONCERNED NUMBER Version(s) 

Civil Military 

EC130 53A019 B4

Revision No. Date of issue

Revision 0 2011-06-14

Revision 1 2014-04-15

Summary: 

Check for cracks in the tail boom/Fenestron junction frame.

Reason for last revision:

The purpose of Revision 1 of this ALERT SERVICE BULLETIN is:

- To extend the inspection to the entire circumference of the frame.

- To cancel the instructions in this ALERT SERVICE BULLETIN for helicopters which have embodied 

MOD 074609 through SB 53-024.

Compliance: 

Compliance with this ALERT SERVICE BULLETIN is mandatory.

For the attention of
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1. PLANNING INFORMATION 

1.A. EFFECTIVITY 

1.A.1. Helicopters/installed equipment 

- Helicopters equipped with a tail boom assembly fitted with countersunk head rivets at the tail 

boom / Fenestron junction on the Fenestron side, which do not embody:

. modification 073880 (Reinforcement of the tail boom / Fenestron junction),

or

. RDAS No. 350 53 522 07 or 350 53 521 10 or 350 53 524 10 or 350 53 525 10 or 350 53 526 10 or 

350 53 511 11 or 350 53 512 11 or 350 53 523 11 or 350 53 504 12 or RDAS-AE11-0205 or

RDAS-AE11-0380,

or

. modification 074609 (Reinforcement of the tail boom / Fenestron junction through retrofit) (see NOTE 5).

- The helicopter equipped with tail boom assembly number TB 7377 is not concerned by the instructions of 

this ALERT SERVICE BULLETIN.

NOTE 1

Refer to the aircraft individual inspection log book (MOD record) to identify the 

actual configuration of the helicopter. 

NOTE 2

The tail boom assemblies which are not identified by one of the above-mentioned 

RDAS numbers and contain a tail boom / Fenestron junction frame riveted with 

brazier head rivets on the Fenestron side, have embodied modification 073880.

NOTE 3

The RDASs are identified by the marking of their number close to the tail boom 

identification label, visible from the inside of the rear cargo compartment. 

NOTE 4

The tail boom assemblies which have been subject to compliance with Service 

Bulletin No. 53-017 are concerned by the instructions of this ALERT SERVICE 

BULLETIN, except for tail boom assembly number TB 7377.

NOTE 5

The tail boom assemblies which embody MOD 074609 (through Service Bulletin 

No. 53-024) are not concerned by the instructions of this ALERT SERVICE 

BULLETIN.
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1.A.2. Non-installed equipment 

- Tail boom assemblies fitted with countersunk head rivets at the tail boom / Fenestron junction on the

Fenestron side and which do not embody:

. modification 073880 (Reinforcement of the tail boom / Fenestron junction) (See NOTE 2),

or

. RDAS No. 350 53 522 07 or 350 53 521 10 or 350 53 524 10 or 350 53 525 10 or 350 53 526 10 or 

350 53 511 11 or 350 53 512 11 or 350 53 523 11 or 350 53 504 12 or RDAS-AE11-0205 or RDASAE11-0380. (See NOTE 3),

or

. modification 074609 (Reinforcement of the tail boom / Fenestron junction) (See NOTE 5).

- The tail boom assembly with part number TB 7377 is not concerned by the instructions of this ALERT 

SERVICE BULLETIN.

1.B. ASSOCIATED REQUIREMENTS 

Not applicable.
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1.C. REASON 

Revision 0:

Following the issue of Information Notice No. 2167-I-53, EUROCOPTER has received new reports of cracks 

in the tail boom/Fenestron junction frame.

The cracks started in the plane of the rivet head countersinks on the RH side of the Fenestron (Detail E, 

Figure 3) and spread to the web of the frame (Details C and D, Figure 2).

The examination of the parts showed that the cracks were longer than in the previous cases, questioning

easy detection of the cracks from the outside as well as the inspection interval to substantiate the strength of 

the frame.

Consequently, EUROCOPTER rendered compliance with this ALERT SERVICE BULLETIN mandatory, 

whose purpose was to enable a detailed visual check from the outside and inside of the frame and to 

schedule its replacement if a crack is found.

Revision 1:

Airbus Helicopters has defined modification 074609, whose purpose is to limit the risk of cracks appearing on 

the tail boom / Fenestron junction frame.

The purpose of Revision 1 of this ALERT SERVICE BULLETIN is to:

- inform operators that the embodiment of MOD 074609 (Service Bulletin 53-024) cancels the instructions 

defined in this ALERT SERVICE BULLETIN.

- modify compliance with paragraph 1.E.2. by requesting the embodiment of MOD 074609 through Service 

Bulletin 53-024 before 31/12/2017.

- To extend the inspection to the entire circumference of the frame on helicopters defined in paragraph 1.A.

Revision 1 of this ALERT SERVICE BULLETIN affects compliance with Revision 0.

1.D. DESCRIPTION 

Compliance with this ALERT SERVICE BULLETIN consists in checking for cracks in the tail boom/Fenestron 

junction frame.

1.E. COMPLIANCE 

NOTE 6

In the following paragraphs, use the contact information below to contact the 

Technical Support Department of the Customer Service:

Tel.: +33 (0)4.42.85.97.16.

Fax: + 33 (0)4.42.85.99.66.

E-mail: airframe.technical-support@eurocopter.com

NOTE 7

Airbus Helicopters reminds you that a visual check for cracks is scheduled at the 

flight-related check (VLV) as per AMM Task 05-40-00,6-1 and makes it possible to 

detect a crack, if any.

1.E.1. Compliance at the works 

Not applicable.
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1.E.2. Compliance in service 

Helicopters/installed equipment: The work on the helicopter is to be performed by the operator. 

a)Within 10 flying hours following receipt of Revision 0 of this ALERT SERVICE BULLETIN, issued 

on 14/06/2011:

. Comply with paragraphs 3.B.1. and 3.B.2. pending compliance with paragraphs 3.B.3. and 3.B.4.

Interpretation of results following compliance with paragraphs 3.B.1.and 3.B.2.:

1) Presence of a crack entirely crossing the web (c) of frame (a) (See detail D, Figure 2):

. All flights are prohibited.

. For the conditions for returning the helicopter to service, contact the Customer Service Technical 

Support Department (See NOTE 6).

2) Presence of a crack crossing part of the web (c) of frame (a):

. All flights are prohibited except for the ferry flight not exceeding 10 flying hours.

. For the conditions for returning the helicopter to service, contact the Customer Service Technical 

Support Department (See NOTE 6).

3) Presence of a crack on the outside of frame (a) and no crack in the web (c) of frame (a):

. Comply successively with paragraphs 3.B.3. (unless already carried out) and 3.B.4. 

4) If no crack is found: 

. Flights can be continued.

. Pending compliance with paragraphs 3.B.3. and 3.B.4., comply with paragraphs 3.B.1. and 3.B.2. at 

periodic intervals not exceeding 40 flying hours.
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b) Within 110 flying hours following the last inspection without exceeding 6 months following receipt of

Revision 1 of this ALERT SERVICE BULLETIN, issued on the date indicated at the bottom of the page:

. Comply with paragraphs 3.B.3. and 3.B.4. successively.

Interpretation of results following compliance with paragraphs 3.B.3. and 3.B.4.:

1) Presence of a crack reaching the radius of frame (a) (Figure 3): 

. All flights are prohibited beyond 85 flying hours following the inspection (compliance with paragraph 

3.B.4. or the flight-related check (VLV)) prior to the one during which a crack, reaching the radius 

of frame (a), was detected, except for the ferry flight not exceeding 10 flying hours. 

. Comply with paragraph 3.B.1. at periodic intervals not exceeding 40 flying hours.

. For the conditions for returning the helicopter to service, contact the Customer Service Technical 

Support Department (See NOTE 6).

2) Presence of a crack not reaching the radius of frame (a) (Figure 3):

. All flights are prohibited after 12 months from initial detection of a crack on the outside of the 

frame, except for the ferry flight not exceeding 10 flying hours.

. Comply successively with paragraphs 3.B.1. and 3.B.4. at periodic intervals not exceeding 40 flying 

hours. 

. Inform the Customer Service Technical Support Department (See NOTE 6).

3) If no crack is found:

. Flights can be continued.

. Pending compliance with Service Bulletin 53-024, comply with paragraph 3.B.4. at periodic intervals 

not exceeding 100 flying hours.

. Comply with Service Bulletin 53-024 (MOD 074609) before 31/12/2017.
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Strip the area on 

the outside of the 

frame (§ 3.B.3)

Check stripped area 

on the outside of 

frame (§ 3.B.4)

Yes

Crack on the 

outside (T1)

Crack 

entirely 

crossing 

the web

Yes

No Crack?

110 flying hours // 

6 months since T0

Check stripped area 

on the outside of the 

frame (§ 3.B.4)

Or

No

Check for cracks on the inside and outside 

(§ 3.B.1. and 3.B.2.)

Within 10 flying hours from 

receipt of this ALERT SERVICE 

BULLETIN Revision 0 (T0)

Check for cracks on the inside and 

the outside (§ 3.B.1. and 3.B.4) Check the inside of 

the frame (§ 3.B.1)

Crack on the 

inside

Strip the area on 

the outside of the 

frame (§ 3.B.3)

FLIGHT PROHIBITED except for 

ferry flight ≤10 flying hours.

Contact Airbus Helicopters

40 flying 

hours

100 

flying 

hours

40 flying 

hours

40 flying 

hours

 12 months

 since T1?

Does the crack on 

the outside reach the 

radius of the frame?

Crack on the inside or

85 flying hours since 

T2?

No Yes

No

Yes

Yes

No

Contact Airbus Helicopters Crack on the 

outside ?

k on the outside ?

Crack crossing 

part of the web

FLIGHT 

PROHIBITED

except for 

ferry flight 

≤10 flying 

hours.

Contact

Airbus 

Helicopters

FLIGHT 

PROHIBITED. 

Contact Airbus 

Helicopters

Yes= T1

No

Key:

T0: date of receipt of this 

EASB Rev 0.

T0: date of receipt of this 

EASB Rev 1.

T1: date of initial detection 

of a crack on the 

outside.

T2: date of the inspection 

prior to the one during 

which a crack, reaching 

the radius of the frame, 

was detected.

Comply with SB 

53-024 before

31/12/2017

Airworthiness 

Directive

lifted
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Non-installed equipment:

Before installation on a helicopter, comply with paragraph 3.

1.F. APPROVAL 

Approval of modifications:

Not applicable.

Approval of this document:

The technical information contained in this ALERT SERVICE BULLETIN Revision 0 was approved 

on June 10, 2011 under the authority of EASA Design Organization Approval No. 21J.056 for helicopters of 

civil versions subject to an Airworthiness Certificate. 

The technical information contained in this ALERT SERVICE BULLETIN Revision 1 was approved 

on April 08, 2014 under the authority of EASA Design Organization Approval No. 21J.056 for helicopters of 

civil versions subject to an Airworthiness Certificate.

1.G. MANPOWER 

Airbus Helicopters recommends that compliance with this ALERT SERVICE BULLETIN be ensured by 

personnel with the following qualification: 

Qualification: 1 Mechanical Engineering Technician or Aircraft Structure Technician (paragraph 3.B.)

and/or,

1 suitably trained pilot, qualified in accordance with local regulations (paragraphs 3.B.1.,

3.B.2. and 3.B.4.). 

The time for the operations is given for information purposes, for a standard configuration. 

Time for the operations: Approximately 10 minutes for compliance with paragraph 3.B.1.

Approximately 10 minutes for compliance with paragraph 3.B.2.

Approximately 4 hours for compliance with paragraph 3.B.3. excluding drying time.

Approximately 30 minutes for compliance with paragraph 3.B.4.

1.H. WEIGHT AND BALANCE 

Not applicable.

1.I. EFFECT ON ELECTRICAL LOADS 

Not applicable.

1.J. SOFTWARE MODIFICATION EMBODIMENT RECORD 

Not applicable.
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1.K. REFERENCES 

The following documents are necessary for compliance with this ALERT SERVICE BULLETIN. 

Standard Practices Manual (MTC): 

MTC: 20.02.07.403: Applying VERNELEC 43022 varnish.

MTC: 20.04.01.102: Description and use of standard cleaning products for individual parts and on aircraft.

MTC: 20.04.02.401: Stripping organic surface coatings. 

MTC: 20.04.05.101: General information concerning painting means and paint touch-ups. 

MTC: 20.04.05.402: EPOXY primer P05-P20 scheme.

Aircraft Maintenance Manual (AMM): 

AMM: 55-11-00,4-1: Removal/Installation - Horizontal stabilizer

1.L. DOCUMENTS AFFECTED 

Modification 074609 of this ALERT SERVICE BULLETIN will be integrated into the following manual:

- MSM.

These documents will be issued subsequently.

1.M. INTERCHANGEABILITY OR MIXABILITY OF PARTS 

Not applicable.
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2. MATERIAL INFORMATION 

2.A. MATERIAL: PRICE - AVAILABILITY - PROCUREMENT 

Not applicable.

2.B. INFORMATION CONCERNING INDUSTRIAL SUPPORT 

Not applicable.

2.C. MATERIAL REQUIRED FOR EACH HELICOPTER/COMPONENT 

Products to be ordered separately:

Refer to the Work Cards and Tasks specified in this ALERT SERVICE BULLETIN and the list below: 

Designation Qty Product P/N CM Item 

No. 

Primer P05 A/R DHS186-111.20 CM 487 1

Primer P20 A/R DHS186-111.40 CM 488 2

VERNELEC varnish A/R ECS2228.10 CM 514 3

The products can be ordered separately from the INTERTURBINE AVIATION LOGISTICS company. 

Website: http://www.interturbine.com

Telephone: +49.41.91.809.300

AOG: +49.41.91.809.444

2.D. MATERIAL TO BE RETURNED 

Not applicable.
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3. ACCOMPLISHMENT INSTRUCTIONS 

3.A. GENERAL 

Read and comply with the general instructions concerning painting means and paint touch-ups as per MTC 

Work Card 20.04.05.101.

3.B. OPERATIONAL PROCEDURE 

3.B.1. Inspection of the RH side of the tail boom/Fenestron junction frame from the inside (Figures 1 and 2)

- Check that there is no crack in the web (c) of frame (a) on the RH side (Details C and D, Figure 2) using a 

light source positioned in front of the opening of the drive shaft tube and by looking through the yaw control 

opening in the Fenestron (Detail B, Figure 1).

 

FOR THIS INSPECTION, THE SURFACE OF THE 

FRAME MUST BE CLEAN.

- If necessary, clean the web (c) of junction frame (a):

. Remove the horizontal stabilizer as per AMM Task 55-11-00,4-1.

. Clean junction frame (a) as per MTC Work Card 20.04.01.102.

. Install the horizontal stabilizer as per AMM Task 55-11-00,4-1.

- Interpret the results in accordance with paragraph 1.E.2. a). 

3.B.2. Inspection of the RH side of the tail boom/Fenestron junction frame from the outside before stripping

(Figures 1 and 2)

- Check that there is no crack on the external surface of junction frame (a) (Detail A, Figure 1).

- Interpret the results in accordance with paragraph 1.E.2. a). 

3.B.3. Stripping the entire circumference of the tail boom/Fenestron junction frame (Figure 3)

- Remove the cowling (b).

- Strip the two rows of rivets over the circumference of the junction frame on the Fenestron side up to the tail 

boom coating, as per Detail E and as per MTC Work Card 20.04.02.401:

. over the visible width of 45 mm (1.771 in.) from the cowling (b).

- Apply a coat of primer (1) or (2) to the stripped area as per MTC Work Card 20.04.05.402.

- Apply varnish (3) to the stripped area as per MTC Work Card 20.02.07.403.

- Install the cowling (b)

3.B.4. Inspection of the entire circumference of the tail boom/Fenestron junction frame from the outside after 

stripping (Figure 3)

- Remove the cowling (b).

- Check that there are no cracks in the area stripped in accordance with paragraph 3.B.3.

- Interpret the results as per paragraph 1.E.2. b).

- Install the cowling (b).

CAUTION
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3.C. IDENTIFICATION

Identification of this document:

Record initial compliance with this ALERT SERVICE BULLETIN in the helicopter documents.

3.D. OPERATING AND MAINTENANCE INSTRUCTIONS

Not applicable.
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Figure 1

C

a
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Figure 2

c

D

c
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Figure 3: shows the partial stripping of the frame

a

Area to be stripped 

over the entire 

circumference of the 

frame

45 mm (1.771 in.)

DETAIL of the Area to be stripped

a

radius of frame (a)

b