## BOLLETTINO TECNICO N° 

# 139-133

The technical content of this document is approved under the authority of DOA nr. EASA.21J.005 DATE February 20, 2009

REV. A – March 17, 2009

Compliance with this bulletin is:

Page 1 of 4 SUBJECT: GENERATOR CONTROL UNI T (GCU) P/N 1152550-5

REASON: to replace GCU P/N 1152550-3 with improved version P/N 1152550-5.

HELICOPTERS AFFECTED: AB139/AW139 helicopters from S/N 31005 up to S/N 31143 (except S/N 31007, S/N 31037, S/N 31038, S/N 31094 and S/N 31112), from S/N 31146 up to S/N 31148, S/N 31 155, from S/N 31201 up to S/N 31218 and from S/N 41001 up to S/N 41022 (except S/N 41007).

NOTE Implementation of this revision is required also for helicopters that have compli ed with the first issue of
this Bollettino.

COMPLIANCE: within 6 months from receipt of this Bollettino.

DESCRIPTION: the modification described in this Bo llettino improves Electrical Power Generation and Distribution Sy stem functionalities, in particular the overvoltage protection and the ground f ault protection device.

## B.T. 139-133 Rev.A

Page 2 of 4 REQUIRED MANPOWER: it is estimated that in order to accomplish this Bollettino four (4) man-hours are necessary.

WARRANTY: upon request, the parts required to ap ply this Bollettino Tecnico shall be supplied on a Free of C harge basis by Agusta. Upon application of this Bollettino Tecnico, Customers are reques ted to submit to Agusta Warranty Administration a Mainten ance Malfunction Information report duly completed in all its parts.

REQUIRED MATERIALS: the following materials, necessary to accomplish this bollettino, can be required to AgustaWestland:
P/N DESCRIPTION Q.TY (1) (2) 1152550-5 GCU AR (2 minimum)

Moreover, the following consumable materi als are necessary to accomplish this
bollettino:
SPEC./AW Code Number DESCRIPTION. Q.TY
A556A-22 Wire 0.5 m

Notes: (1) GCU P/N 1152550-3 repl acement must be extended to all modules kept in storage. (2) GCU P/N 1152550-4 may be supplied (q .ty 2 minimum) as an alternative to P/N 1152550-5. G CU P/N 1152550-4 and P/ N 1152550-5 are not intermixable.

SPECIAL TOOLS: N.A.

WEIGHT AND BALANCE CHANGES: N.A.

REFERENCES: A. AW139 Aircraft Maintenance Publication (AMP)

## B.T. 139-133 Rev.A

Page 3 of 4 PUBLICATIONS AFFECTED:
9 AW139 Illustrated Parts Data (IPD)

COMPLIANCE INSTRUCTIONS:
1. Prepare the helicopter for a safe ground maintenance. Disconnect the battery and all the electrical power sources and/or the exter nal power supply. Refer to AMP, see data
module n° 39-A-00-20 -00-00A-120A-A.

2. Remove the Number 1 generat or control unit (refer to AMP, see data module n° 39-A24-31-03-00A-520A-A) and send it to AgustaWestland.

3. Remove the Number 2 generat or control unit (refer to AMP, see data module n° 39-A24-31-04-00A-520A-A) and send it to AgustaWestland.

4. With reference to figure 1, perform modi fication as shown on the electrical connector A13P1 before connecting it to t he generator control unit A13.

5. Install the new Number 1 generator control unit P/N 1152550-5. Refer to AMP, see
data module n° 39-A- 24-31-03-00A-520A-A.

6. With reference to figure 1, perform modi fication as shown on the electrical connector A14P1 before connecting it to t he generator control unit A14.

7. Install the new Number 2 generator control unit P/N 1152550-5. Refer to AMP, see
data module n° 39-A- 24-31-04-00A-520A-A.

8. Check every spare GCU kept in stock. In case the P/N is 11525 50-3, send the GCU to AgustaWestland. It must be replac ed with a new spare part 1152550-5.

9. Return helicopter to flight configuration and record for compliance of this Bollettino.

## B.T. 139-133 Rev.A

Page 4 of 4 Figure 1 BT133A22-G BT133B22-G Applicable to helicopters S/N 31005 up to S/N 31143 (except S/N 31007, S/N 31037, S/N 31038, S/ N 31094 and S/N 31112), from S/N 31146 up to S/N 31148, S/N 31155 and from S/N 41001 up to S/N 41022 (except S/N 41007)

Applicable to helicopter s from S/N 31201 up to S/N 31218

BT133B22-G

BT133A22-G A 46C22-G P90B22-GNote: Remarks:

Informazioni: Information: Al fine di gestire le varianti alla configur azione base, in relazione all’emissione de l Bollettino Tecnico, preghiamo di voler compilare il presente modulo in tutte le sue parti e sped irlo all’indirizzo sopra indicato. Si ring razia per la gentile collaborazione data. We request your cooperation in filling this form, in order to keep out statistical data relevant to aircraft configuration up- to-date. The form should be filled in all its parts and sent to the above address. We thank you beforehand for the information given. **MODULO APPLICAZIONE BOLLETTINO TECNICO** TECHNICAL BULLETIN COMPLIANCE FORM Data: Date:

Numero: Number:

Revisione: Revision: Prego spedire a questo indirizzo: Please send to the following address: 

### AGUSTA **S.p.A.**
PRODUCT SUPPORT ITALY Via per Torna v en t o, 15 21019 Som m a Lombardo (VA) - I T ALY T el

. : +39 0331 711100 Fa x : +39 0331 711 180

Telefono: Telephone:

Fax:

Data Applicazione B.T.: B.T. Compliance Date: Denominazione Cliente ed Indirizzo: Customer Name and Address:

Modello Elicottero

Helicopter Model S/N Matricola Tail Number Ore Totali Total Hours Ore D.U.R. T.S.O.