ALERT SERVICE BULLETIN EC130 

Approved under EASA DOA No. 21J.056. 53A008 Page 1/19

 2006.07.19

 EUROCOPTER

DIRECTION TECHNIQUE SUPPORT

13725 MARIGNANE CEDEX FRANCE CIVIL VERSION(S): B4 

 

 

ALERT SERVICE BULLETIN 

No. 53A008 

 

 

SUBJECT: FUSELAGE

Containment box structure installation for cabin vibration damper weights

Corresponds to MOD 073565. 

REVISION No. DATE OF APPROVAL DATE OF ISSUE 

 

No. 0 2006.07.07 2006.07.19 

 
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1. PLANNING INFORMATION 

1.A. EFFECTIVITY 

1.A.1. Helicopters / Equipment installed on aircraft 

Helicopters pre-MOD 073565. 

NOTE 1

Refer to Individual Inspection Log Book (RIC) (RIC AMS), equipment Log 

Cards (FM) or aircraft Log Book to identify the actual modification status 

of the aircraft. 

1.A.2. Equipment not installed on aircraft 

Not applicable. 

1.B. ASSOCIATED REQUIREMENTS 

Not applicable. 

1. C. REASON 

To install a cabin vibration damper containment device, in case of vibration damper blade failure, preventing 

any contact with flying control items located underneath the cabin floor. 

This Alert Service Bulletin will form the subject of an EASA Airworthiness Directive. 

Compliance with this Alert Service Bulletin will supersede the prescriptions in Telex Alert No. 05A002 

Revision 1. 

This information is made official by Revision 0 of Alert Service Bulletin No. 05A002. 

NOTE 2

It is mandatory to install two box structures, on RH side and on 

LH side of aircraft, for compliance with the instructions in Telex 

Alert No. 05A002. 
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1.D. DESCRIPTION 

Eurocopter was advised of a case of cabin vibration damper blade failure. This failure was found further to a 

change in the aircraft vibration level felt by the aircrew. 

A complementary analysis of the vibration damper blade failure consequences showed that the loose broken 

part, which remains contained in the lower fairing, could interfere with the flying controls, and finally result in 

a possible jamming. 

Pending a modification, Eurocopter published Telex Alert 05A002 requiring a check for any crack on RH and 

LH cabin vibration damper assembly blades. 

Therefore, Eurocopter developed a vibration damper containment device avoiding any interference in case 

of vibration damper blade failure. Containment of cabin vibration damper is ensured by installing a box 

structure, solid with the airframe structure underneath aircraft bottom structure. In case of vibration damper 

blade failure, the loose parts will be contained, which will avoid any interference with the environment 

underneath the cabin floor. 

Therefore Eurocopter renders compliance with this Alert Service Bulletin mandatory. 

This Alert Service Bulletin also indicates the maintenance (defined in § 2.D.) to be applied to these box 

structures: this will be introduced in Master Servicing Recommendations in section 05.22.00 and not in 

section "Airworthiness Limitations ". 

1.E. COMPLIANCE 

Eurocopter renders compliance with this Alert Service Bulletin mandatory. 

1.E.1. Compliance at the works 

1.E.1.a. On helicopter 

For helicopters pre-MOD 073565, comply with paragraph 2.B. of this Alert Service Bulletin. 

1.E.1.b. On equipment not installed on aircraft 

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

1.E.2.a. On helicopter / equipment installed on aircraft: By operator 

For aircraft pre-MOD 073521 (SB 53-006), pre-MOD 073525 (SB 53-007) (none of the two MODs 

embodied), comply with paragraphs 2.B.1., 2.B.2. and 2.B.5. of this Alert Service Bulletin at the latest by 

31 March 2007. 

For aircraft post-MOD 073521 (SB 53-006) or MOD 073525 (SB 53-007), comply with paragraphs 2.B.1., 

2.B.3. and 2.B.5. of this Alert Service Bulletin at the latest by 31 March 2007. 

1.E.2.b. On equipment not installed on aircraft: 

Not applicable. 

1.F. APPROVAL 

Approval is limited to civil version helicopters subject to Airworthiness Certificate. 

1.F.1. Approval of modifications 

The information or instructions relate to MOD 073565 which was approved on 16 February 2006. 

1.F.2. Approval of the Service Bulletin 

The technical information contained in this Alert Service Bulletin No. 53A008 Revision 0 was approved on 7 

July 2006 under the authority of EASA Design Organization Approval No. 21J.056. 
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1.G. MANPOWER 

1.G.1. Qualification 

For compliance with this Alert Service Bulletin, Eurocopter recommends the following personnel 

qualifications: 

Qualification: 1 Airframe Technician 

1.G.2. Time 

Time values are indicated for reference, for a standard configuration. 

Time: 4 hours for 1 Airframe Technician 

1.G.3. Estimation of aircraft downtime 

4 hours. 

1.H. WEIGHT AND BALANCE 

On completion of the work mention weights and moments in the "Weight & Balance" sheet (Flight Manual). 

1.H.1. Weight 

For aircraft post-MOD 073521 or MOD 073525: 

Weight: 0.420 kg. 

For aircraft pre-MOD 073521 and pre-MOD 073525 (none of the two MODs embodied): 

Weight: 0.450 kg. 

1.H.2. Moment 

For aircraft post-MOD 073521 or MOD 073525: 

Longitudinal moment: 0.55 m.kg. 

For aircraft pre- MOD 073521 and pre-MOD 073525 (none of the two MODs embodied): 

Longitudinal moment: 0.59 m.kg. 

1.I. EFFECT ON ELECTRICAL LOADS 

Not applicable. 
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1.J. SOFTWARE MODIFICATION EMBODIMENT STATE 

Not applicable. 

1.K. REFERENCES 

The following documents are required for compliance with this Alert Service Bulletin: 

- Aircraft Maintenance Manual (AMM): 

Task 24-00-00, 3-1: General instructions - Electrical 

Task 53-51-00, 4-2: Removal / Installation - Lower cowlings 

- Standard Practices Manual (MTC): 

Work Cards 20-02-01-415: Installation of electrical cable bundles 

Work Cards 20-02-05-404: Assembling by bolts and nuts 

Work Cards 20-07-03-408: General principles applicable for visual cleanliness, appearance checks on an 

aircraft after an inspection or repair 

1.L. OTHER DOCUMENTS AFFECTED 

This Service Bulletin will give rise to amendment of the following documents by Eurocopter: 

- Aircraft Maintenance Manual (AMM) 

- Illustrated Parts Catalog (IPC) 

- Master Servicing Recommendations (PRE) 

These documents will be circulated at a later date. 

1.M. TOOLING AFFECTED 

Not applicable. 

1.N. INTERCHANGEABILITY AND MIXABILITY BETWEEN THE PARTS 

1.N.1. Interchangeability 

Non interchangeable. 

1.N.2. Mixability 

Refer to NOTE 2 of paragraph 1.C. 
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2. ACCOMPLISHMENT INSTRUCTIONS 

2.A. GENERAL 

Depending on the Aircraft Maintenance Manual (AMM). 

Refer to general safety instructions on electrical generation as per Task 24-00-00, 3-1. 

As per Standard Practices Manual (MTC). 

Protect electrical wiring during maintenance or modification operations as per Work Card 20-07-03-408. 

2.B. OPERATIONAL PROCEDURE 

2.B.1. Preliminary steps 

- Disconnect all electrical power supply. 

- Remove front lower cowlings: central (h), LH side (l) and RH side (i) (Figure 1 and 2) as per Task 53-51-

00, 4-2 (AMM). 

2.B.2. Embodiment of MOD 073565 for aircraft pre- MOD 073521, pre-MOD 073525 (none of the two MODs 

embodied). 

 

NOTE 1

Installation of vibration damper box structure assembly on RH 

side of aircraft is identical to that on LH side (Figure 1). 

 Installation of box structures on vibration dampers does not affect the adjustment process. 

2.B.2.a. Installation of box structure/vibration damper assembly on aircraft LH side (Figure 1) 

As per Figure 1-DETAIL A 

- Remove rivet (k) from cross-member (j) and counter-drill hole for rivet (k) to diameter 5.5 mm (Section 

B-B). 

- Remove: 

• 4 self-locking nuts (a), 

• 4 washers (d), 

• 4 bolts (m), 

- Scrap nuts (a), washers (d) and bolts (m). 

As per Figure 1-DETAIL B 

- Offer up and install unequipped box structure (4) on vibration damper. 

- Install unequipped box structure (4) with: 

• 4 coils (12), 

• 4 spherical washers (13), 

• 4 washers (11), 

• 4 bolts (10), 

• 4 self-locking nuts (14). 
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NOTE 2

Flats on coils and on spherical washers are positioned 

specifically. They must be directed outward fitting. 

NOTE 3

Do not fit washers underneath 4 self-locking nuts (14). 

- Tighten to tightening torque (DETAIL B). 

- Offer up blanking plate assembly (1) on unequipped box structure (4). 

- Assemble blanking plate (1) by means of 2 washers (3) and 2 bolts (2). 

- Tighten bolts (2) to standard torque as per Work Card 20-02-05-404 (MTC). 

- Tighten box structure assembly by means of bolt (6), 2 washers (7) (1 underneath bolt head, 

1 underneath nut) and nut (8). 

- Carry out visual checks of aircraft as per Work Card 20-07-03-408 (MTC). 

2.B.3. Embodiment of MOD 073565 for aircraft post-MOD 073521 or MOD 073525 

 

 Installation of box structures on vibration dampers installation does not affect adjustment process. 

2.B.3.a. Installation of box structure/vibration damper assembly on aircraft RH side (Figure 2) 

- Remove rivet (k) from cross-member (j) and counter-drill hole for rivet (k) to diameter 5.5 mm (Section 

D-D). 

- Remove chronologically, recording the removed items (DETAIL B): 

• 4 self-locking nuts (t), 

• 4 washers (b), 

• 4 bolts (c), 

• 8 washers (d), 

• 4 spherical washers (e), 

• 4 coils (f). 

- Scrap nuts (t) and washers (d). 

- Keep folding shims (p), (q), (r), (s) in place (DETAIL C). 

- Offer up and install unequipped box structure (4) on vibration damper (DETAIL B). 

- Install unequipped box structure (4) in previously recorded order, with: 

• 4 coils (f), 

• 4 spherical washers (e), 

• 4 washers (5), 

• 4 bolts (c), 

• 4 washers (b), 

• 4 self-locking nuts (15). 

NOTE 4

Flats on coils and spherical washers are positioned specifically. 

They must be directed outward fitting. 
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- As per DETAIL C, adjust profiles of folding shims (p), (q), (r) and (s), only at blending radii identified as 

(R) on fittings. The other shim radii may be out of contact with other radii on fittings. 

- Tighten to torque (DETAIL B). 

- Offer up blanking plate assembly (1) on unequipped box structure (4). 

- Assemble blanking plate (1) by means of 2 washers (3) and 2 bolts (2). 

- Tighten bolts (2) to standard torque as per Work Card 20-02-05-404 (MTC). 

- Tighten box structure assembly by means of bolt (6), 2 washers (7) (1 underneath bolt head, 1 

underneath nut) and nut (8). 

- Carry out visual checks of aircraft as per Work Card 20-07-03-408 (MTC). 

2.B.3.b. Installation of box structure/vibration damper assembly on aircraft LH side (Figure 3) 

- Remove rivet (n) from cross-member (j) and counter-drill hole for rivet (n) to diameter 5.5 mm (Section 

C-C). 

- Remove chronologically, recording the removed items (DETAIL E): 

• 4 self-locking nuts (t), 

• 4 bolts (m), 

• 4 washers (d), 

• 4 spherical washers (e), 

• 4 coils (f). 

- Scrap nuts (t) and washers (d). 

- Offer up and install unequipped box structure (4) on vibration damper (DETAIL E). 

- Install unequipped box structure (4) in previously recorded order, with: 

• 4 bolts (m), 

• 4 washers (5), 

• 4 coils (f), 

• 4 spherical washers (e), 

• 4 self-locking nuts (15). 

NOTE 5

Flats on coils and of spherical washers are positioned 

specifically. They must be directed outward fitting. 

NOTE 6

Do not fit washers underneath 4 self-locking nuts (15). 

- Tighten to torque as per DETAIL E. 

- Offer up blanking plate assembly (1) on unequipped box structure (4). 

- Assemble blanking plate (1) by means of 2 washers (3) and 2 bolts (2). 

- Tighten bolts (2) to standard torque as per Work Card 20-02-05-404 (MTC). 

- Tighten box structure assembly by means of bolt (6), 2 washers (7) (1 underneath bolt head, 1 

underneath nut) and nut (8). 

- Carry out visual checks of aircraft as per Work Card 20-07-03-408 (MTC). 
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2.B.4. Tests 

Not applicable. 

2.B.5. Final steps 

- Re-install front lower cowlings: central (h), RH side (i), LH side (l) (Figures 1 and 2). 

- Reconnect all electrical power supplies as per Work Card 20-07-03-406 (MTC). 

- Restore aircraft to flight condition. 

2.B.6. Retrofitting of spare part stocks 

Not applicable. 

2.C. IDENTIFICATION 

2.C.1. Identification of modifications in the documents 

Record embodiment of Modification 073565 and compliance with this Alert Service Bulletin No. 53A008 

Revision 0 in the aircraft documents. 

2.C.2. Identification of modifications on material 

Not applicable. 

2.D. OPERATING AND MAINTENANCE INSTRUCTIONS 

2.D.1. Operating instruction(s) 

Not applicable. 

2.D.2. Maintenance instruction(s)

Check condition of vibration damper box structures every 500 hours or 2 years (whichever occurs first), with 

respect to the following criteria: 

- Check for cracks, deformations, wear or corrosion. 

- Check presence of all nuts & bolts and check bolt tightening. 

In case of cracks, deformations, wear or corrosion, replace box structure. 

Master Servicing Recommendations (PRE) will integrate this instruction in section 05.22.00 "Inspection 

periodicities" at the time of the next Revision. After integration of this instruction in Master Servicing 

Recommendations (PRE), refer to the PRE. 
ALERT SERVICE BULLETIN EC130 

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3. MATERIAL INFORMATION 

3.A. MATERIAL: COST – AVAILABILITY 

3.A.1. COST 

The kits and/or components will be delivered free of charge on operator's order until 31 March 2007. 

3.A.2. Availability 

The kits or components will be delivered upon operator's order. 

3.B. INFORMATION CONCERNING INDUSTRIAL SUPPORT 

Not applicable. 

3.C. MATERIAL REQUIRED FOR EACH HELICOPTER/ENGINE/COMPONENT 

3.C.1. Kit to be ordered for one helicopter 

Material P/N Qty It. Key Word It. Former P/N Instruction 

 

 Helicopters pre-MOD 073521, pre-MOD 073525 (none of the 2 

embodied) 

 

350A07-3565-0072 Kit including 

 

350A21-4922-01 2 1 Plate assy, blanking 

22125BC050012L 4 2 Bolt 

23116AG050LE 4 3 Washer 

350A21-4922-20 2 4 Structure, box, 

unequipped 

 

22125BE050016L 2 6 Bolt 

23111AG050LE 4 7 Washer 

ASN52320BH050N 2 8 Nut 

22201BE060052L 8 10 Bolt 

23116AG060LE 8 11 Washer 

350A08-7029-21 8 12 Coil 

332A22-1948-20 8 13 Washer, spherical 

ASN52320BH060N 8 14 Nut a ASN52320BH060N Scrap 
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Material P/N Qty It. Key Word It. Former P/N Instruction 

 

 Helicopters post-MOD 073521 or MOD 073525 

 

350A07-3565-0071 Kit including 

 

350A21-4922-01 2 1 Plate assy, blanking 

22125BC050012L 4 2 Bolt 

23116AG050LE 4 3 Washer 

350A21-4922-20 2 4 Structure, box, 

unequipped 

 

23116AG080LE 8 5 Washer d 23112AG080LE Scrap 

22125BE050016L 2 6 Bolt 

23111AG050LE 4 7 Washer 

ASN52320BH050N 2 8 Nut 

 9 Not in use 

ASN52320BH080N 8 15 Nut t ASN52320BH080N Scrap 

3.C.2. Material to be ordered separately 

Not applicable. 

3.C.3. Ingredient (s) to be ordered separately 

The ingredients required for compliance with Tasks and Work Cards mentioned can be ordered from 

INTERTURBINE. 

Website: http://www.itlogistics.de

Telephone: +49.41.91.809.300 

AOG: +49.41.91.809.444 

As per Work Cards and Tasks mentioned in this Alert Service Bulletin. 

3.C.4. Tooling(s) 

As per Work Cards and Tasks mentioned in this Alert Service Bulletin. 

3.C.5. Material required for item not installed on aircraft 

Not applicable. 
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3.D. PROCUREMENT CONDITIONS 

Order the required quantity from the EUROCOPTER network's Customer Support Sales Department, 

or from 

EUROCOPTER 

Etablissement de Marignane 

Direction VENTES Service Client (S.V.) 

13725 MARIGNANE CEDEX 

FRANCE 

NOTE

For ALERT SERVICE BULLETINS, order by: 

Telex: HELICOP 410 969F 

Fax: +33 (0)4.42.85.99.96. 

4. APPENDIX 

Not applicable.