## BOLLETTINO TECNICO N° 

# 139 -3 92

The technical content of this document is approved under the authority of DOA nr. EASA.21J.005 DATE September 23 , 2014

REV
. /

Compliance with this bulletin is:

Page 1 of 14 SUBJECT LOWER HALF SCISSOR SPECIAL NUT P/N 3G6230A06851

REASON Introduce an interim inspection and a special nut for containment.

HELICOPTERS AFFECTED Part I: all AB139/AW139 helicopters installing MR Rotating Scissors P/N 3G6230A00733

. Part II: all AB139/AW139 helicopters installing MR Rotating Scissors P/N 3G6230A00733 and not installing special nut P/N 3G6230A06851

.

COMPLIANCE Part I : on helicopters not installing special nut P/N 3G6230A06851 within five (5) flight hours or one (1) week from receipt of this Bollettino Tecnico, whichever comes first, then daily, up to accomplishment of Part II, and then every twenty-five (25) flight hours after accomplishment of Part II.
on helicopters already installing special nut P/N 3G6230A06851 every twenty-five (25) flight hours from receipt of this Bollettino Tecnico

## B.T. 139
- 3 92

Page 2 of 14 Part II : within one hundred (100) flight hours or one (1) month from receipt of this Bollettino Tecnico whichever comes first.

DESCRIPTION This Bollettino Tecnico introduces a special nut as a containin g element in case of lower scissor bearing dislodging providing additional safety to the installation. This represents a further follow

- up action in addition to those already fielded to address the early failures in service due to a quality issue with the lower scissor spherical bearing liner. An interim inspection program is also introduced to monitor the behavior of the spherical bearings in service

.

REQUIRED MANPOWER I t is estimated that, in order to accomplish this Bollettino Tecnico , the following mai ntenance man

- hours (MMH) are necessary: Part I : one (1) MMH; Part II : one ( 1 ) MMH

. Man

- hours are based on hands

- on time and may vary with personnel and facilities available.

WARRANTY  Within the calendar terms mentioned at point “Compliance”, the parts requ ired to apply the present Bollettino shall be supplied on a free of charge basis by AgustaWestland upon Customers request, except for consumable materials and special tools.  Upon application of this Bollettino, Customers are requested to submit to AgustaWe stland Warranty Administration the relevant W.M.M. (Warranty Claim/Maintenance Work Order/Malfunction Report).

## B.T. 139
- 3 92

Page 3 of 14 REQUIRED MATERIALS
T he following materials, necessary to accomplish Part II of this Bollettino Tecnico , can be requested to AgustaWestland:
P/N D ESCRIPTION Q.TY Note
3G6230A06851 Special nut 2 NAS1149C0863R Washer, flat 2 MS24665

- 302 Pin, cotter 2
Moreover the following consumable materials, or equivalent, are necessary to comply with P art II of this Bollettino Tecnico:
Spec./AW code number DESCRIPTION Q.TY Note
MIL

- PRF

- 16173E INT AMD 1, grade 2 cod. 999999999000000191 Corrosion inhibitor (C0 02 ) AR Local supply

Refer to AMDI for the consumable materials necessary to comply with the AMP data modules referenced in this Bollettino Tecnico.

SPE CIAL TOOLS
T he following special tools are necessary to accomplish this Bollettino Tecnico:

P/N DESCRIPTION Q.TY NOTES
RMGE

- DS

- 06

- 2010

- LH or an approved alternative Platform (GG

- 01

- 00)
AR (1) RMGE

- DS

- 06

- 2010

- RH or an approved alternative Platform (GG

- 02

- 00)

Local supply Magnifying glass AR (2) Local supply Hand torch AR (2)
3G6205G26631 Wrench, special nut removal/installation AR ( 3 )

## B.T. 139
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Page 4 of 14 Notes: (1) Refer to Illustrated Tools and Equipment Publication (ITEP) for this special tool and also for other special tools required to comply with the AMP data modules referenced in this Bollettino Tecnico. (2) Required to comply only with P art I of this Bollettino Tecnico. (3) Required to comply only with P art II of this Bollettino Tecnico.

WEIGHT AND BALANCE CHANGES N.A.

REFER ENCES  AW139 Aircraft Maintenance Data Information (AMDI)  AW139 Aircraft Maintenance Publication (AMP)  AW139 Illustrated Tools and Equipment Publication (ITEP)

PUBLICATIONS AFFECTED  AW139 Aircraft Maintenance Publication (AMP)  AW139 Illustrated Parts Data ( IPD)  AW139 Illustrated Tools and Equipment Publication (ITEP)

## B.T. 139
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Page 5 of 14 COMPLIANCE INSTRUCTIONS
Part I
1. Prepare the helicopter for a safe ground maintenance. Disconnect the battery and all the electrical power sources and/or the external power supply. Refer to AMP, see DM n° 39

- A

- 00

- 20

- 00

- 00A

- 120A

- A.
2. Put the platforms (GG

- 01

- 00) and (GG

- 02

- 00), or approved alternatives, adjacent to the left and to the right side of the fuselage, respectively.
3. Open access door 473AL

. Refer to AMP, see DM n° 39

- A

- 06

- 41

- 00

- 00A

- 010A

- A.
4. W ith reference to Figure 1, get access to the MR area and perform a general visual inspection of the MR rotating scissors P/N 3G6230A00733 , using a magnifying glass and a hand torch, paying particular attention to the spherical bearings. If you find damages ( a typical damage is shown in figures 4 thru 8 ) , contact AW139 Product Support Engineering (aw139.mbx@agustawestland.com).
5. With reference to Figure 1, perform an operational check for play and wear of the lower half scissors spherical bearing P/N 3G6230V0 0654 (refer to section A

- A), paying particular attention to the bearing staking condition; to do this , manually move the lower half scissor along the axis of the spherical bearing.
5.1. If no unusual play and/or wear is detected, no further action is required. Go to step 6

. 5.2. If unusual play and/or wear is detected, perform a detailed inspection for condition, damage and play of the MR rotating scissors according to steps 9 through 12.9 of AMP DM n° 39

- C

- 62

- 31

- 00

- 00A

- 286C

- A.
5.2.1. If play is within limits, no further ac tion is required. Go to step 6

. 5.2.2. If play is beyond limits or wear is detected, report findings to AW139 Product Support Engineering (aw139.mbx@agustawestland.com).
6. Close access door 473AL. Refer to AMP, see DM n° 39

- A

- 06

- 41

- 00

- 00A

- 010A

- A.
7. Remove the platfor ms from left and right sides of the fuselage.

## B.T. 139
- 3 92

Page 6 of 14 8. Return the helicopter to flight configuration and record for compliance with Part I of this Bollettino Tecnico on the helicopter logbook.

Part II
1. Prepare the helicopter for a safe ground maintenance. Disconnect the battery and all the electrical power sources and/or the external power supply. Refer to AMP, see DM n° 39

- A

- 00

- 20

- 00

- 00A

- 120A

- A.
2. Put the platform (GG

- 01

- 00), or an approved alternative, adjacent to the left side of the fuselage.
3. Open access door 473AL

. Refer to AMP, see DM n° 39

- A

- 06

- 41

- 00

- 00A

- 010A

- A.
4. With reference to figure 2 , get access to the MR rotating scissors area.
5. With reference to figure 3, replace the lower half scissor existing nut as follows :
5.1. Remove and discard the cotter pin P/N MS24665

- 3 02.
5.2. Remove and discard the nut P/N MS17825

- 8

. 5.3. Remove from the scissor retaining bolt the lower half scissor , washers P/N NAS1149C0832R and scissor washer P/N 3G6230A04552 . Retain scissor washer P/N 3G6230A04552 for re

- use.
WARNI N G THIS INSTALLATION INCLUDE S VITAL POINTS (VP). YOU MUST OBEY THE LOCAL REGULATIONS APPLICABLE TO THE VITAL POINTS.
CAUTION Make sure that the chamfered side of the scissor washer P/N 3G6230A04552 points to the spherical bearing in the lower half scissor.
5.4. Install the lower half scis sor on the scissor retaining bolt using new washer P/N NAS1149C0863R and scissor washer P/N 3G6230A04552

.

## B.T. 139
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Page 7 of 14 5.5. Install the new special nut P/N 3G6230A06851.
5.6. Apply the wrench P/N 3G6205G26631 to the special nut.
5.7. Torque the special nut to 61.0 thru 73.2 N m (5 39. 9 thru 64 7.9 lbf in) with the wrench P/N 3G6205G26631

. 5.8. S ecure the special nut to the retaining bolt with a new cotter pin P/N MS24665

- 302.
5.9. Apply the c orrosion i nhibitor (C002) to the cotter pin and the special nut.
6. Repeat step 5 to replace the other lower half scissor nut.

7. Close the access door 473AL. Refer to AMP, see DM n° 39

- A

- 06

- 41

- 00

- 00A

- 010A

A.
8. Remove the platform from the left side of the fuselage.
9. Return helicopter to flight configuration and record for compliance with Part II of this Bollettino Tec nico on the helicopter logbook.

## B.T. 139
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Page 8 of 14 Figure 1

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Page 9 of 14 Figure 2

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Page 10 of 14 Figure 3

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Page 11 of 14 Figure 4

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Page 12 of 14 Figure 5

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Page 13 of 14 Figure 6

Figure 7

## B.T. 139
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Page 14 of 14 Figure 8Note: 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 **WESTLAND S.p.A.**  CUSTOMER SUPPORT & SERVICES - ITALY PRODUCT SUPPORT ENGINEERING DPT. Via del Gregge, 100 2101 5 Lonate Pozzolo (VA) - I T ALY T el

. : +39 0331 664905 Fa x : +39 0331 66468 4
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.