### SERVICE BULLETIN EC120

Approved under DGAC DOA No. F.JA01 

# 71-005 Page 1/18

2004.05.14 EUROCOPTER

DIRECTION TECHNIQUE SUPPORT

13725 MARIGNANE C EDEX F RANCE 

### CIVIL VERSION(S): B



# SERVICE BULLETIN

No. 71-005

SUBJECT : POWER PLANT

Spring-type engine suspension system

LIST OF APPROVED REVISIONS REVISION No. 0 APPROVED

Not applicable Date: May 13, 2004

### SERVICE BULLETIN EC120

Approved under DGAC DOA No. F.JA01 

# 71-005 Page 2/18

2004.05.14 

### 1. PLANNING INFORMATION

1.A. EFFECTIVITY

1.A.1. Helicopters

Helicopters type EC 120, version B.

1.A.2. Component(s) affected

Engine mount and flared coupling assembly, P/N C631A1101101.



### 1.B. ASSOCIATED REQUIREMENTS

Not applicable.



### 1.C. REASON

- To suppress risks of engine suspension locking by installing a new type of damping system. - To cancel the visual periodical inspection requested in paragraph 1.C. of Alert Service Bulletin No. 05A003,

Revision 2.



### 1.D. DESCRIPTION

The modification consists of: - Replacing the stack of upper spring washers by a helical compression spring. - Replacing the upper washer by a new part ensuring upper centering of the spring. - Installing a removable ball ring type engine deck feedthrough ensuring lower centering of the spring. - Cancelling the current sealing well and adding a s ealing boot ensuring sealing of the engine/cargo

compartment. - Removing the spacer. - Performing a die penetrant inspection of the flared coupling assembly, P/N C631A1101101.

### SERVICE BULLETIN EC120

Approved under DGAC DOA No. F.JA01 

# 71-005 Page 3/18

2004.05.14 1.E. APPLICATION

Compliance with this Service Bulletin is at operator's/client's initiative.

1.E.1. At the works

1.E.1.a. On aircraft

From serial number 1386.

1.E.1.b. Spares

Upon Customer's request.

1.E.2. Retrofit action on the operator's site

1.E.2.a. On aircraft

By operators.

1.E.2.b. Spares

Before installation on aircraft, carry out die penetrant inspection as per paragraph 2.B.2.a. on flared couplings P/N C631A1101101 mounted on aircraft.



### 1.F. APPROVAL

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

1.F.1. Approval of modifications

The information or instructions relate to Aircraft Modification Approval Form (FAM) No. A00570 issue 1 which was approved on March 08, 2004 under No. 2004/3445 by DGAC according to Article 10.3 of U.E. regulation

1592/2002.

1.F.2. Approval of the Service Bulletin

The technical information contained in Revision 0 of this Service Bulletin No. 71-005 was approved on May 13, 2004 under the authority of DGAC Design Organisation Approval No. F.JA01.



### 1.G. MANPOWER

- Qualification: 1 mechanic. - Time: 14 hours approximately.

### SERVICE BULLETIN EC120

Approved under DGAC DOA No. F.JA01 

# 71-005 Page 4/18

2004.05.14 1.H. WEIGHT AND BALANCE

- Weight: + 0.103 kg.

- Moment / x: + 0.5 daN.m.



### 1.I. EFFECT ON ELECTRIC LOADS

Not applicable.



### 1.J. SOFTWARE MODIFICATION EMBODIMENT STATE

Not applicable.



### 1.K. REFERENCES

Aircraft Maintenance Manual (AMM):
Tasks: 20-10-00,3-1, 20-10-00,3-2, 20-10-00,3-3, 20-10-00,3-4, 20-10-00,3-7, 20-10-00,3-10,
20-10-00,3-14, 20-10-00,3-19, 20-10-00,3-27, 24-00-00,2-1, 24-00-00,3-1, 63-11-00,6-1,
71-00-00,3-1, 71-41-00,4-1, 72-01-00,4-1, 72-01-00,4-2, 72-01-00,6-1.



### 1.L. OTHER DOCUMENTS CONCERNED

Illustrated Part Catalogue (IPC). Aircraft Maintenance Manual (AMM). Master Servicing Manual (MSM).



### 1.M. INTERCHANGEABILITY OR MIXABILITY OF PARTS

1.M.1. Interchangeability

The new assembly is mounted in replacement of the former assembly (with spring washer stack). It is not interchangeable.

1.M.2. Mixability

- The new and former P/N's are not mixable. - The whole flared coupling P/N C631A1101101 which has already been used in flight with the washer-type

suspension system must be checked by die penetrant method in the area of the suspension bar, as per AMM Task 20-10-00,3-19, before installation on the aircraft equipped with a spring-type engine suspension
system.

### SERVICE BULLETIN EC120

Approved under DGAC DOA No. F.JA01 

# 71-005 Page 5/18

2004.05.14 

### 2. ACCOMPLISHMENT INSTRUCTIONS

2.A. GENERAL

- Comply with general instructions on the power plant as per AMM Task 71-00-00,3-1. - Comply with general instructions on electrical generation as per AMM Task 24-00-00,3-1. - Implement and energise the electrical networks from the ground power supply as per AMM

Task 24-00-00,2-1. - Checks after interventions on ARRIUS 2F engine as per AMM Task 72-01-00,6-1. - Bonding as per AMM Task 20-10-00,3-4. - Safetying as per AMM Task 20-10-00,3-1. - Torquing as per AMM Task 20-10-00,3-2. - MASTINOX sealant application method as per AMM Task 20-10-00,3-3. - Sealant application method as per AMM Task 20-10-00,3-14. - Alodine application method as per AMM Task 20-10-00,3-7. - Paint primer application method as per AMM Task 20-10-00,3-10. - Rivet installation and replacement method as per AMM Task 20-10-00,3-27. - Die penetrant inspection method as per AMM Task 20-10-00,3-19. - Detailed check of flared coupling assembly as per AMM Task 63-11-00,6-1.



### 2.B. OPERATIONAL PROCEDURE

CAUTION

BEFORE ANY INTERVENTION ON THE POWER PLANT,

READ THE GENERAL INSTRUCTIONS AS PER TASK 71-00-00,3-1 (AMM)

.

2.B.1. Preliminary steps

- Implement suitable access means. - Disconnect the electrical power supply sources as per AMM Task 24-00-00,2-1.

2.B.2. Replacement of the spring-type engine suspension system (Figures 1, 2, 3 and 4)

2.B.2.a. Preliminary steps (Figures 1 and 2)

As per Figure 1: - Remove Arrius 2F engine as per AMM Task 72-01-00,4-1. - Remove engine mount fitting (y) as per AMM Task 71-41-00,4-1. - Scrap special washer (n), s pecial bolt (o), spacer (p), wa sher (r) and spring washers (s). - Parts (a), (b), (c), (d), (e), (q), (t) are to be replaced systematically as per AMM Task 71-41-00,4-1.

As per Figure 2: - Carry out detailed check of flared coupling (a) as per AMM Task 63-11-00,6-1. - Carry out die penetrant inspection of flared coupling (a) in external (A) and internal (B) areas as per AMM

Task 20-10-00,3-19. - Flared coupling (a) will be replaced if crack is found.

### SERVICE BULLETIN EC120

Approved under DGAC DOA No. F.JA01 

# 71-005 Page 6/18

2004.05.14 2.B.2.b. Installation of the new deck attachment system (Figures 3 and 4)

As per Figure 3:

- Remove fitting (z) and blank holes (B) with rivets (3) as per AMM Task 20-10-00,3-27, and protect with

sealant (15).

- Scrap fitting (z).



### NOTE 1

If rivet (3) drilling diameter exceeds 4.2, it is acceptable to fit repair rivets ASNA0078E505X.

- Drill 8 holes on engine deck with tooling (Y) as per Figure 3:

• 3 holes (C), countersunk on both sides.

• 3 holes (D), counterbored to match beam (m).

• 1 hole (E), chamfered as per detail (A) and counterbored and protected as per AMM Task
20-10-00,3-7 and 20-10-00,3-10.

• 1 hole (F), protected as per AMM Tasks 20-10-00,3-7 and 20-10-00,3-10.

As per Figures 3 and 4:

- Offer up and install reinforcement plate assy (1) with rivets (5) after interlaying sealant (15) as per AMM

Task 20-10-00,3-14 on all faces in contact.

- Offer up and secure dish (2) with rivets (4) after interlaying sealant (15) as per AMM Task 20-10-00,3-14

on all faces in contact.

2.B.2.c. Installation of engine mount fitting (y) (Figure 4)

- Offer up and install cross beam (8) with bolt (9) and washer (10).

- Torque as per AMM Task 20-10-00,3-2.



### NOTE 2

When installing washers (t), interlay grease (16) between

each washer.

- Offer up and install bolt (7), equipped with 3 spring washers (t) and seal (q) and maintain the assembley

through engine deck.

- Onto bolt (7), fit spring (13), centering washer (6) and sealing boot (14).

- Onto bolt (7), fit hinge nut (f).

### SERVICE BULLETIN EC120

Approved under DGAC DOA No. F.JA01 

# 71-005 Page 7/18

2004.05.14 - Offer up and install washer (e), nut (d), and tighten to torque.

- Safety with pin (c) as per AMM Task 20-10-00,3-1.

- Install clamps (11) and (12) on boot (14) and tighten as per AMM Task 20-10-00,3-2.

- Offer up LH support arm (g) and RH support arm (h), LH square (i) and RH square (j).



### NOTE 3

Check parallelism of support arms (g) and (h) with engine fittings (u), before tightening bolts (a) to torque.

- After bonding as per AMM Task 20-10-00,3-4, offer up LH (i) and RH (j) squares with washers (b),

bonding braid (l) and bolts (a), after interlaying sealant (18) between the parts in contact, as per
AMM Task 20-10-00,3-3.

- Reinstall engine as per AMM Task 72-01-00,4-2.

- Tighten bolts (a) to torque and safety with lockwire (17) as per AMM Task 20-10-00,3-1.

- Apply sealing bead with sealant (15) around squares (i) and (j), and coat bolt heads (a) as per

AMM Task 20-10-00,3-14.

2.B.3. Functional tests

Carry out checks after intervention on engine as per AMM Task 72-01-00,6-1.

2.B.4. Final steps

- Remove the access means.

- De-energize the electrical system of the helicopter as per AMM Task 24-00-00,2-1.

- Restore the aircraft to flight condition.

2.B.5. Spare parts

2.B.5.a. Retrofitting of spare part stocks

Not applicable.

2.B.5.b. Replacement of spare part stocks

Check flared couplings P/N C631A1101101 by die penetrant inspection method as per
AMM Task 20-10-00,3-19.

### SERVICE BULLETIN EC120

Approved under DGAC DOA No. F.JA01 

# 71-005 Page 8/18

2004.05.14 2.C. IDENTIFICATION

Record compliance with this Service Bulletin Revision 0 in the aircraft documents. Record embodiment of this Service Bulletin in the flared coupling log card (FME).



### 2.D. OPERATING AND MAINTENANCE INSTRUCTIONS

2.D.1. Operating instruction(s)

Not applicable.

2.D.2. Maintenance instruction(s)

For flared coupling assemblies P/N C631A1101101 which have already been used in flight with a engine suspension system before Service Bulletin No. 71-005, the retrofitting of the new spring-type suspension system allows exoneration from visual checks required at paragraph 1.C. of Alert Service Bulletin No. 05A003, Revision 2, subject to a possible crack detection in the area of the suspension bar (no crack admissible), by die penetrant inspection method as per AMM Task 20-10-00,3-19, before clearing the aircraft for flight.

### SERVICE BULLETIN EC120

Approved under DGAC DOA No. F.JA01 

# 71-005 Page 9/18

2004.05.14 Figure 1 PRE MOD

### SERVICE BULLETIN EC120

Approved under DGAC DOA No. F.JA01 

# 71-005 Page 10/18

2004.05.14 Figure 2SERVICE BULLETIN EC120Approved under DGAC DOA No. F.JA0171-005Page 11/182004.05.14Figure 3SERVICE BULLETIN EC120Approved under DGAC DOA No. F.JA0171-005Page 12/182004.05.14PAGE LEFT BLANK INTENTIONALLYSERVICE BULLETIN EC120Approved under DGAC DOA No. F.JA0171-005Page 13/182004.05.14Figure 4POST MODSERVICE BULLETIN EC120Approved under DGAC DOA No. F.JA0171-005Page 14/182004.05.14PAGE LEFT BLANK INTENTIONALLY

### SERVICE BULLETIN EC120

Approved under DGAC DOA No. F.JA01 

# 71-005 Page 15/18

2004.05.14 

### 3. MATERIAL INFORMATION

3.A. MATERIAL: COST - AVAILABILITY

For all information, contact the Customer Support Sales Department.



### 3.B. INFORMATION CONCERNING INDUSTRIAL SUPPORT

Not applicable.



### 3.C. MATERIAL REQUIRED FOR EACH AIRCRAFT, ENGINE / COMPONENT

3.C.1. Kit or component(s) to be ordered

New P/N (in MPN) Qty Item Key word Former P/N Instructions Disposition

C008A153306871 Kit including:

C533A7190101 1 1 Plate, reinforcement, assy

C533A7190202 1 2 Dish

ASNA0078E504 4 3 Rivet

ECS2151DXJ3206 3 4 Rivet

ECS2152DXJ3210 3 5 Rivet C714A1112201 1 6 Washer, centering C714A1112202 1 7 Bolt, special

C714A1112203 1 8 Cross beam

22125BC050020L 1 9 Bolt

23111AG050LE 1 10 Washer ASNA0033-090 1 11 Clamp ASNA0033-045 1 12 Clamp 7050A3710013 1 13 Spring 706A34-560-017 1 14 Boot, sealing

3.C.2. Items to be ordered separately

As per Tasks mentioned in the previous Service Bulletin and:

New P/N (in MPN) Qty Item Key word Former P/N Instructions Disposition

EN3628-1 A/R 17 Lockwire

### SERVICE BULLETIN EC120

Approved under DGAC DOA No. F.JA01 

# 71-005 Page 16/18

2004.05.14 3.C.3. Ingredient to be ordered separately

As per Tasks mentioned in this Service Bulletin and:

New P/N (in MPN) Qty Item Key word Former P/N Instructions Disposition

ASN42112PF A/R 15 Sealant

AIR 4222 A/R 16 Grease

MASTINOX 6856 K A/R 18 MASTINOX sealant

3.C.4. Material delivered by the customer

Not applicable.

3.C.5. Tooling

As per Tasks mentioned in this Service Bulletin and:

New P/N Qty Item Key word Former P/N Instructions Disposition

4801C008A153306800 1 Y Drilling tool



### 3.D. MATERIAL REQUIRED FOR EACH SPARE PART

3.D.1. Kit to be ordered

Not applicable.



### 3.E. RE-IDENTIFIED PARTS

Not applicable.



### 3.F. TOOLING: COST - AVAILABILITY

For all information as regards tooling renting, contact the Customer Support Sales Department.

### SERVICE BULLETIN EC120

Approved under DGAC DOA No. F.JA01 

# 71-005 Page 17/18

2004.05.14 3.G. PRO CUREMENT CONDITIONS

3.G.1. Material

Order the required quantity

from

EUROCOPTER Etablissement de Marignane

Direction VENTES Service Client

S.V.

13725 MARIGNANE CEDEX

FRANCE



### NOTE

On the purchase order, please specify the mode of transport,

the destination and the serial numbers of the aircraft to be

modified.

3.G.2. Ingredients

The ingredients listed in this Service Bulletin and in the reference documents can be ordered from the INTERTURBINE company:

Website : http://www.itlogistics.de Telephone : +49.41.91.809.300

AOG : +49.41.91.809.444

### SERVICE BULLETIN EC120

Approved under DGAC DOA No. F.JA01 

# 71-005 Page 18/18

2004.05.14 

### 4. APPENDIX

Not applicable.