### T.F.S. No. 00000577

Approved under EASA DOA No. 21J.056. Page 1/11

2010.04.22 EUROCOPTER

DIRECTION TECHNIQUE SUPPORT

13725 MARIGNANE C EDEX F RANCE



# EMERGENCY 

# ALERT SERVICE BULLETIN

COLIBRI Number VERSIONS

Civil: B 

# EC120 24A012

SUBJECT: ELECTRICAL POWER

EMERgency SWitch (EMER SW) wiring

REVISION No. DATE OF APPROVAL DATE OF ISSUE

Revision 0 On: April 22, 2010 2010.04.22

This document is available on the internet: www.eurocopter.com/techpub

### T.F.S. No. 00000577

Approved under EASA DOA No. 21J.056. Page 2/11

2010.04.22 THE INFORMATION AND INSTRUCTIONS

CONTAINED IN THIS ALERT SERVICE BULLETIN

ARE INTENDED FOR MAINTENANCE PERSONNEL

AND FLIGHT CREWS.



### 1. PLANNING INFORMATION

1.A. EFFECTIVITY

1.A.1. Helicopters/installed equipment

Helicopters equipped with "EMER SW" switch with a Serial Number (S/N) listed below:

- S/N 1500,

- S/N between 1511 and 1630 (terminals included),

- S/N 1632, 1634 and 1636.

1.A.2. On non-installed equipment

Not applicable.



### 1.B. ASSOCIATED REQUIREMENTS

Not applicable.



### 1.C. REASON

Modification of the "EMER SW" switch wiring.

This ALERT SERVICE BULLETIN will form the subject of an EASA Airwor thiness Directive.



### 1.D. DESCRIPTION

As part of a test conducted at EUROCOPTER, the "smoke in the cockpit" procedure was applied. It

was found that setting the "EMER SW" switch to "CUT-OFF" (low position) and the "GENE"

pushbutton to "OFF" at the same time, caused t he aircraft starter-generator to cut-in again.

The technical investigations conducted revealed t hat cross-wiring at the "EMER SW" switch caused

the malfunction. In this configuration, the "smoke in the cockpit/cargo" procedure described in the flight

manual does not isolate the equipment electrical power supply.

Consequently, EUROCOPTER renders the embodiment of the modification described in this ALERT

SERVICE BULLETIN, mandatory. 

### CAUTION

### T.F.S. No. 00000577

Approved under EASA DOA No. 21J.056. Page 3/11

2010.04.22 

### 1.E. COMPLIANCE

EUROCOPTER renders compliance with th is ALERT SERVICE BULLETIN mandatory.

1.E.1. Compliance at the works

1.E.1.a. On helicopters

Not applicable.

1.E.1.b. On non-installed equipment

Not applicable.

1.E.2. Compliance in service: By the operator

1.E.2.a. On helicopters/installed equipment

- Comply with paragraph 2.B of this ALERT SER VICE BULLETIN within 15 flight hours, without

exceeding 1 month, following receipt of this ALERT SERVICE BULLETIN, issued on the date

indicated at the foot of the page.

- Before the next flight following receipt of th is ALERT SERVICE BULLETIN, inform the flight

crews of the content of this ALERT SERVIC E BULLETIN and draw their attention to the

instruction below:

Pending compliance with paragraph 2.B., in case of smoke in the cockpit with a source not

identified, the flight crew mu st follow the appended procedure.

1.E.2.b. Non-installed equipment

Not applicable.



### 1.F. APPROVAL

1.F.1. Approval of modifications

The information or instructions related to FAM No. RFA 08090 ap proved on April 9, 2010 by EASA for

civil version helicopters subject to an Airworthiness Certificate.

1.F.2. Approval of the Service Bulletin

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

on April 22, 2010 under the author ity of EASA Design Organisation A pproval No. 21J.056 for civil

version helicopters subject to an Airworthiness Certificate.

### T.F.S. No. 00000577

Approved under EASA DOA No. 21J.056. Page 4/11

2010.04.22 

### 1.G. MANPOWER

1.G.1. Qualification

- 1 electrical engineering technician (Modifica tion to the wiring as per § 2.B.2.).

- 1 pilot or 1 approved technician entitled to perform run-up.(Tests as per § 2.B.4.).

1.G.2. Time for the operations

- Approximately 30 minutes (Modificatio n to the wiring as per § 2.B.2.).

- Approximately 30 minutes (Tests as per § 2.B.4.).



### 1.H. WEIGHT AND BALANCE

Not applicable.



### 1.I. EFFECT ON ELECTRICAL LOADS

Does not affect the helicopter electrical power breakdown.



### 1.J. SOFTWARE MODIFICATION EMBODIMENT RECORD

Not applicable.



### 1.K. REFERENCES

- Aircraft Maintenance Manual (AMM):

AMM: Task 24-00-00,3-1.



### 1.L. OTHER DOCUMENTS AFFECTED

The following documents will be issued subsequently:

- Wiring Diagrams Manual (WDM).



### 1.M. TOOLING AFFECTED

Not applicable.



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

Not applicable.

### T.F.S. No. 00000577

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2010.04.22 

### 2. ACCOMPLISHMENT INSTRUCTIONS

2.A. GENERAL

- Read and comply with the general instructions co ncerning the electrical power supply as per AMM

Task 24-00-00,3-1.



### 2.B. OPERATIONAL PROCEDURE

2.B.1. Preliminary steps

- Remove the instrument panel vizor (a).

2.B.2. Wiring modification (Figures 1 and 2)

- Using tool (zz), reconnect "EMER SW" (3PA) switch wires in compliance with Figure 2:

. Wire marked "2431-0016" to terminal "3PA-1A".

. Wire marked "2431-0003" to terminal "3PA-2A".

2.B.3. Final steps

- Install the instrument panel vizor (a).

2.B.4. Tests

To validate correct operation of the "EMER SW" switch, the following tests must be performed:

- Set the helicopter into the following configuration:

. [AVIONIC] (if installed) ON

. [BAT/EPU] ON

. [EMER SW] ON

. Start-up the helicopter

. [GENE] ON

- Perform the following tests:

. [EMER SW]: OFF

Check that the equipment items are no longe r energized, except: the engine, NR / NTL

instrument and emergency lights (utility lights).

. [BAT/EPU]: OFF

Check that the equipment items are no longe r energized, except: the engine, NR / NTL

instrument and emergency lights (utility lights).

. [GENE]: OFF

Check that the equipment items are no longe r energized, except: the engine, NR / NTL

instrument and emergency lights (utility lights).

. [EMER SW]: ON

Check that the equipment items are no longe r energized, except: the engine, NR / NTL

instrument and emergency lights (utility lights).

### T.F.S. No. 00000577

Approved under EASA DOA No. 21J.056. Page 6/11

2010.04.22 . [BAT/EPU]: ON

Check that all equipment items are energized.

. [BAT/EPU]: OFF

. [GENE]: ON

Check that all equipment items are energized.

- Stop the engine and rotors.

- Replace snapwire (b) (Figure 1) with snapwire (1).



### 2.C. IDENTIFICATION

- Record compliance with this ALERT SERV ICE BULLETIN in the helicopter documents.



### 2.D. OPERATING AND MAINTENANCE INSTRUCTIONS

2.D.1. Operating instructions

Not applicable.

2.D.2. Scheduled maintenance instructions

Not applicable.

2.D.3. Unscheduled maintenance instructions

Pending update of WDM 24-30-01-002, refer to t he wiring diagram of Figure 2, when performing a

maintenance operation on the "EMER SW" switch.

The wiring modification will be incorporated in WDM 24-30-01-002 as part of a future revision.

### T.F.S. No. 00000577

Approved under EASA DOA No. 21J.056. Page 7/11

2010.04.22 Figure 1 - "EMER SW" Switch

### T.F.S. No. 00000577

Approved under EASA DOA No. 21J.056. Page 8/11

2010.04.22 Figure 2 - "EMER SW" Switch Wiring 

## POST EASB 24A012

PRE EASB 24A012

### T.F.S. No. 00000577

Approved under EASA DOA No. 21J.056. Page 9/11

2010.04.22 

### 3. MATERIAL INFORMATION

3.A. MATERIAL: PRICE AND AVAILABILITY

3.A.1. Cost

Not applicable.

3.A.2. Availability

Not applicable.



### 3.B. INFORMATION CONCERNING INDUSTRIAL SUPPORT

Not applicable.



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

3.C.1. Kits or components to be ordered for one helicopter or one assembly

Not applicable.

3.C.2. Products to be ordered separately

Material P/N Qty Item Key Word

* 23321 A/R 1 Snapwire

The products identified by an asterisk "*" or r equired for compliance with the Tasks and/or

Work Cards listed in paragraph 1.K., can be ordered from:

INTERTURBINE,

Website: http://www.itlogistics.de

Phone: +49.41.91.809.300

AOG: +49.41.91.809.444

3.C.3. Tools

Material P/N Qty Item Key Word

M81969-14-11 1 zz Extraction tool

### T.F.S. No. 00000577

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2010.04.22 

### 3.D. PROCUREMENT CONDITIONS

Order the required quantity (unless otherwise specified)

from

EUROCOPTER

Etablissement de Marignane

Direction Ventes et Relations Client

ECR

13725 MARIGNANE CEDEX

FRANCE



### NOTE 1

For ALERT SERVICE BULLETINS, order by:

Telex: HELICOP 410 969F.

Fax: +33 (0)4.42.85.99.96



### NOTE 2

On the purchase order, please specify the mode of

transport, the destination and the serial numbers of

the helicopters to be modified.



### 4. APPENDIX

The "Smoke in the cockpit/cargo - Source not identified" procedure is appended.

### T.F.S. No. 00000577

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2010.04.22 Appendix