Via Giovanni Agusta, 520

21017 Cascina Costa di Samarate (VA) Italy

Tel.: +39 0331-229111 - Fax: +39 0331-229605/222595

An Company

BOLLETTINO TECNICO N° 139-050

The technical content of this document is approved
under the authority of DOA nr. EASA.21J.005 DATE October 31, 2007

REV. /

Compliance with
this bulletin is: OPTIONAL

SUBJECT: DIRECTION FINDER KIT P/N 3G3450F00911 INSTALLATION.

REASON: provide the necessary instructions to permit the installation of the subject DF
kit.

HELICOPTERS AFFECTED: AB139/AW139 helicopters S/N 31005 and subsequent

(except S/N 31007) and S/N 41001 and subsequent.

NOTE
“PRIMUS EPIC®” Flight Software release 4.8.0 is
required for the DF kit installation.

COMPLIANCE: at customer’s option.

COMPLIANCE WITH PREVIOUS ACCOMPLISHMENT: N.A.

DESCRIPTION: AgustaWestland has developed a Direction Finder kit P/N

3G3450F00911.
Kit consists of a DF antenna P/N 935-2 to be installed on lower fuselage and a DF
controller P/N 715-40-00010 to be installed on the interseat console. The Direction

An appropriate entry should be made in the aircraft log book upon accomplishment.
If ownership of aircraft has changed, please, forward to new owner.

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B.T. 139-050 Rev. /

Finder 935-2 with 715-40-00010 controller is a stand-alone direction finding system

with an integral synthesised receiver covering 30 to 470 MHz and 5 separate guard
receivers to monitor predefined distress frequencies.
Moreover structural and electrical provisions are required to perform the right and
complete DF installation.
This bollettino is issued to provide all the necessary procedures to perform the above
mentioned installation.

REQUIRED MANPOWER:

PART I: it is estimated that in order to accomplish part I of this Bollettino

approximately twenty-five (25) man-hours are necessary.
PART II: it is estimated that in order to accomplish part II of this Bollettino
approximately twenty (20) man-hours are necessary.
PART III: it is estimated that in order to accomplish part III of this Bollettino
approximately two (2) man-hours are necessary.
Man-hours are based on hands-on time and may vary with personnel and facilities
available.

WARRANTY: N.A.

REQUIRED MATERIALS:

NOTE
A new auxiliary C/B panel is required to apply this
Bollettino.
Customer must contact AW139 Customer Support
Engineering (aw139.mbx@agustawestland.com) at
least 3 months in advance from the scheduled
Bollettino application, to request the new auxiliary
C/B panel.

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 B.T. 139-050 Rev. /

The following materials, necessary to accomplish this bollettino, can be required to

AgustaWestland:
Part I:
P/N DESCRIPTION Q.TY
3G3450F00911 Direction Finder Kit Ref
Composed by:
3G3450A01811 DF Complete Provision Ref
Composed by:
3G5310A14811 DF Structural Provision Ref
Composed by:
3G5310A15531 DF Antenna Fairing Assy …1
3G5310A15751 Upper Hole Protection …1
3G5310A15851 Lower Hole Protection …1
MS51957-41 Screw …6
NAS1149C0332B Washer …6
NAS1836-08-15 Insert …6

Part II:
P/N DESCRIPTION Q.TY
3G3450F00911 Direction Finder Kit Ref
Composed by:
3G3450A01811 DF Complete Provision Ref
Composed by:
3G3450A01911 DF Electrical Provision Ref
Composed by:
3G9B01A11201 DF C/A (B1A112) ...1
3G9B01B11201 DF C/A (B1B112) ...1
3G9B02B11001 DF C/A (B2B110) ...1
3G9C02B10801 DF C/A (C2B108) ...1
A630A31 Support ...1
A630A51 Support ...1
A656A01 Relay ...1

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B.T. 139-050 Rev. /

P/N DESCRIPTION Q.TY

ED300K81 Decal ...1
MS21042L3 Nut ...2
MS21919WDG9 Clamp ...1
MS3340-1-9 Bracket ...1
MS3420-10 Bushing ...1
MS35207-261 Screw ...1
MS9592-022 Bracket ...1
NAS1149D0332J Washer ...3

Part III:
P/N DESCRIPTION Q.TY
3G3450F00911 Direction Finder Kit Ref
Composed by:
715-40-0010 DF Controller .1
935-2 DF Antenna .1
MS35207-267 Screw .8
ED300E30 Decal .1
ED300PL59 Decal .1
999-0500-85-19 Plate .1
3G3450A01811 DF Complete Provision Ref

Moreover, the following consumable materials are necessary to accomplish this

bollettino:

Part I:
Description / P/N Q.ty Notes
Spec.
199-05-002 Ty. II Cl. 2 Adhesive EA934NA - cod. 900004603 AR /
Part II:

Spec. Description / P/N Q.ty Notes

Commercial Adhesive, FLEXON 241 - cod. 900000262 AR /

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 B.T. 139-050 Rev. /

SPECIAL TOOLS: N.A.

WEIGHT AND BALANCE CHANGES: compliance with this bollettino has the following
affect on weight and balance:
PART I:
WEIGHT ARM MOMENT
1.477 Kg 4305 mm 6358.5 Kgmm
PART II:
WEIGHT ARM MOMENT
0.910 Kg 4196 mm 3818.4 Kgmm
PART III:
WEIGHT ARM MOMENT
6.900 Kg 4109 mm 28352 Kgmm

REFERENCES: N.A.

PUBLICATIONS AFFECTED:
AB139 Rotorcraft Flight Manual (RFM)
AB139 Aircraft Maintenance Publication (AMP)
AB139 Illustrated Parts Data (IPD)

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.
2. Gain access to the rear lower panel P/N 3P5331A02231 on helicopter lower
fuselage (ref. STA 3926 – STA 4781.6).
3. In accordance with figure 1, rework the rear lower panel P/N 3P5331A02231 as
follows:
a) In accordance with figure 1, on rear lower panel P/N 3P5331A02231,
countersign the inserts position using the DF antenna fairing assy as a
template.

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B.T. 139-050 Rev. /

b) Perform six 11.481÷11.609 mm dia holes through the panel external skin and
core, in the positions countersigned at step a.
c) In each hole break the honeycomb core cells all around the circumference as
required, to provide a good housing for the adhesive. Remove all debrids.

CAUTION
During the above mentioned operations, pay
particular attention to avoid honeycomb panel
damages. Moreover, during the drill phase, do not
overheat the panel skin in order to avoid unbonding
between core and skin.
d) Install the six NAS1836-08-15 inserts using adhesive 199-05-002 Type II Class
2. Allow adhesive to cure.
e) In accordance with figure 1, on rear lower panel P/N 3P5331A02231, perform
the 65.0 mm dia hole through the panel skins and core.
f) In the hole break the honeycomb core cells and the skin all around the
circumference as required, to provide a good housing for the adhesive. Remove
all debrids.

CAUTION
During the above mentioned operations, pay
particular attention to avoid honeycomb panel
damages. Moreover, during the drill phase, do not
overheat the panel skin in order to avoid unbonding
between core and skin.
g) Install the upper hole protection P/N 3G5310A15751 and the lower hole
protection P/N 3G5310A15851 using adhesive 199-05-002 Type II Class 2.
Allow adhesive to cure.
4. Return helicopter to flight configuration if necessary and record for compliance of
part I of this bollettino.

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 B.T. 139-050 Rev. /

Part II:
1. Prepare the helicopter for a safe ground maintenance, if necessary. Disconnect the
battery and all the electrical power sources and/or the external power supply.
2. In accordance with figures from 2 to 8, perform the installation of electrical provision
as follows:
a) With reference to cable routing indicated in figures from 2 to 7, remove all the
existing clamps that interfere with the installation of the DF cable assemblies.
b) With reference to cable routing indicated in figures from 2 to 7, route the
following cable assemblies:

3G9B01A11201 DF C/A (B1A112)

3G9B01B11201 DF C/A (B1B112)
3G9B02B11001 DF C/A (B2B110)
3G9C02B10801 DF C/A (C2B108)

NOTE
Use braided tubing P/N A582A where cable
assemblies chafing or contact with structure may
occur.
Use edging P/N A236A where liables can damage
cable assemblies and where abrasion may occur.

NOTE
Remove locally the protective finish to assure the
correct electrical grounding.
c) With reference to figure 6 view C and figure 8, install the support P/N A630A31,
the support P/N A630A51, the MS3340-1-9 bracket and the MS9592-022
bracket using adhesive FLEXON 241.
d) With reference to figure 6 view C, on the MS9592-022 bracket install the
MS21919WDG9 clamp using one MS35207-261 screw, two MS21042L3 nuts
and three NAS1149D0332J washers.
e) With reference to figures 3 and 18, install the relay P/N A656A01 and the
relevant decal P/N ED300K81.

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B.T. 139-050 Rev. /

f) With reference to figures from 3 to 7 and to the wiring diagrams of figures 13

thru 16, perform the electrical connection of the DF cable assemblies
connectors.

NOTE
Refer to figure 16 wiring diagram if EXTERNAL AND
INTERNAL PUBLIC ADDRESS SYSTEM P/N
3G2350F00211 is installed on the helicopter.
g) Secure the installed DF cable assemblies to the existing hardness and airframe
fixing points.
h) Perform a pin-to-pin check on the electrical wiring harness installed.
3 Install the new auxiliary C/B panel. Refer to AW139 Customer Support Engineering
(aw139.mbx@agustawestland.com) for details about the installation.
4 Return helicopter to flight configuration if necessary and record for compliance of
part II of this bollettino.

Part III:
NOTE
“PRIMUS EPIC®” Flight Software release 4.8.0 is
required for the DF kit installation.

1. Prepare the helicopter for a safe ground maintenance, if necessary. Disconnect the
battery and all the electrical power sources and/or the external power supply.
2. Gain access on lower fuselage and in accordance with figures 9 and 10, install the
DF antenna P/N 935-2 as follows:
a) With reference to figure 10, on the DF antenna fairing assy P/N
3G5310A15531, install the DF antenna P/N 935-2 with eight MS35207-267
screws.
b) With reference to figure 6 and figure 12 detail B, from the E30P1 connector,
remove the tie strap P/N 900004953, the sleeve P/N A582A32 and the
protective plug.
c) Connect the E30P1 connector to the DF antenna P/N 935-2.
d) Install decal P/N ED300E30 on DF antenna P/N 935-2.

Page 8 of 36
 B.T. 139-050 Rev. /

3. Gain access to the interseat console and in accordance with figure 11 view looking
interseat console area, install the DF controller P/N 715-40-00010 as follows:
a) Remove the existing plate.
b) With reference to figure 3 and figure 12 detail A, from the PL59P1 connector,
remove the tie strap P/N 900004953, the sleeve P/N A582A32 and the
protective plug.
c) Connect the PL59P1 connector to the DF controller P/N 715-40.
d) Install the DF controller P/N 715-40 on the interseat console.
e) Install decal P/N ED300PL59 on DF controller P/N 715-40.
4. Gain access to the overhead circuit breaker panel and in accordance with figure 9
view C, from the DF breaker, remove the ring of lock P/N Y30700501.
5. With reference to figure 17, update the helicopter setting file to enable DF system
as follows:

DF Installed must be installed

NAV A2 Audio Enable must be enable

6. Perform the acceptance test procedure in accordance with appendix A.
7. Return helicopter to flight configuration and record for compliance of this bollettino.

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B.T. 139-050 Rev. /

Figure 1

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Figure 2

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Figure 3

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Figure 4

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Figure 5

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Figure 6

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Figure 7

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Figure 8

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Figure 9

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Figure 10

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Figure 11

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Figure 12

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FIGURE 14

Figure 13

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Figure 14

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FIGURE 12

Figure 15

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Figure 16

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Figure 17

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 B.T. 139-050 Rev. /

SEE DETAIL A

DETAIL A

SUGGESTED POSITION
TO INSTALL SUPPORT
FOR RELAY K81

Figure 18

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B.T. 139-050 Rev. /

Page intentionally left blank

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 B.T. 139-050 Rev. /

APPENDIX – A

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 B.T. 139-050 Rev. /

5 GROUND TEST PROCEDURE

5.1 SAFETY PROVISION

5.2 TEST EQUIPMENT

The following test equipment is required for the test procedure:

Table 5.1 System Test Equipment List

DEVICE P/N S/N NOTE

DC External Power Bench (28VDC)

DC Voltmeter

Two Headset kit for ICS system

RF Generator or equivalent

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 B.T. 139-050 Rev. /

5.3 TEST PREREQUISITES

The following requirements shall be fulfilled prior to proceeding with the test procedures
described within this document:
1. Visually verify the proper installation of the DF Antenna / Receiver and DF
Controller
2. Ensure Primus EPIC™ S/W rel. 4.8 or successive is installed
3. Before all the test procedures verify that the External Power Bench is operative
and set to the appropriate Voltage (28 VDC)
4. During the test with helicopter electrically powered, the “IGN #1/2” and “START
#1/2” breakers shall be pulled out.

5.4 ELECTRICAL CIRCUIT BREAKERS CONFIGURATION

Table 5.2 Electrical Circuit Breaker Configuration

5.5 PRELIMINARY CHECKS
5.5.1 INSTALLATION AND POWER SUPPLY CHECKS
1. Verify DF Circuit Breaker is pulled out and disconnect all connectors of DF
Antenna and DF Controller
2. With the helicopter electrically powered push in all DF Circuit Breakers
3. Verify the voltage is 28VDC between pins:
PL59P1-M and PL59P1-N (H)
E30P1-M and E30P1-N (H)
4. Pull out all DF Circuit Breakers
5. Reconnect all connectors of DF Antenna and DF Controller.

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 B.T. 139-050 Rev. /

5.6 TEST PROCEDURE

NOTE: Ensure that the aircraft is located in an open area as far away as possible from
buildings, towers, masts or other structures which could cause reflections and interfere with
testing. Note that indicated bearing may not be achieved in some or all check positions due
to reflections from the ground, landing gears, aircraft antennas and surrounding structures.
If bearings greater than those expected are obtained, then the aircraft should be moved to
determine if the error is due to a reflected signal.

5.6.1 MMI – ON GROUND EVALUATION

During the ground tests described in the following paragraphs:
• Verify the DF Controller information display can be clearly visible and correctly
interpreted in all the conditions.
• Evaluate that the DF Controller commands are easily accessible and usable.

5.6.2 POWER UP / DOWN

1. Push in Circuit Breakers, verify the DF system starts without further action
2. If the DF system is OFF, press and hold the On / Off button until the screen
illuminates (approximately 3 seconds) to power ON the system
3. Verify the display initially shows the Splash Screen, which indicates that the unit
is initializing the system
4. Verify (after approximately 2 to 5 seconds) the display changes to the ‘RXR
STATUS’ (Receiver Status) screen display (to avoid communication fault)
5. Press and hold the On / Off button to power OFF the system and verify the
screen blanks (approximately 3 seconds).

5.6.3 MONITORING OPERATION

1. Power ON the DF system (see 5.6.2)
2. Verify all 6 Receivers are monitored simultaneously on the frequencies
displayed
3. By rotating the knob (or pressing the up / down navigation keys) verify
Receivers can be selected (arrow points to the required receiver)
4. Select Receiver 1 (the tunable receiver), press Enter and verify display toggles
between the channel number and the frequency in that channel. Press the Left
(or Right) navigation key and verify the selected channel is Incremented (or
Decremented)
5. Select Receiver 2, 3, and 4 (VHF guard, Maritime guard, and UHF guard
respectively), press Enter and verify display toggles between its main and its
Auxiliary Channel.
6. Select Receiver 5 and 6, verify there are no adjustable selections.

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 B.T. 139-050 Rev. /

5.6.4 DF OPERATION
1. Power ON the DF system (see 5.6.2)
2. Select Receiver 1 (the tunable receiver) to display the bearing data, using the
rotary knob or up / down navigation keys
3. Press the soft-key entitled “DF” and verify the display changes to the DF screen
4. With reference to Figure 5.1 position the test set on the centre line
approximately 10 m in front the aircraft nose and switch ON the test set
5. Set the DF main receiver to the frequency to correspond to the selected test set
(see Table 5.4)
6. Set visualization as primary pointer of DF bearing on both Pilot and Copilot PFD
HSI display by means of Bearing Select Pushbutton of Display Controller
7. Verify that the indicator shows a typical bearing of 0° ± 30° (on DF Controller,
Pilot and Copilot PFD) and note in Table 5.3.
8. Connect headsets to pilot, copilot and hoist operator plugs. Enable DF audio
input by mean the pilot, copilot and hoist operator audio control panel and set it
to middle range volume.
9. Verify that a tone is audible in all headsets and the audio tone volume is
adjustable by the relevant commands on the audio control panel
10. On the Pilot Audio Panel select COM1 Radio and perform transmission
11. Verify when the PTT is pressed the DF holds the last bearing and removes the
signal present status of all receivers (the display shows ‘__PTT__’ for all
receivers in the frequency field)
12. On the Pilot Audio Panel select PA button and perform communication
13. Verify when the PTT is pressed the DF bearing is still present and valid
14. Turn OFF the test set and verify on DF Controller the bearing display is frozen,
and the Age displayed is incremented
15. Verify bearing on PFDs disappears
16. Verify on DF Controller that if the Age displayed exceeds 4 seconds, the
bearing is no longer highlighted, but the last known value is left shown (Note
that typically squelch will close before bearing capability is lost)
17. Switch ON the test set and verify that the indicator shows a typical bearing of 0°
± 30° (on DF Controller, Pilot and Copilot PFD)
18. Verify that pressing the SLW soft key the SLEW function is enabled and the
displayed bearing angle moves. Release SLW and verify the display returns to
show bearing to target only if a valid bearing is being detected

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 B.T. 139-050 Rev. /

Figure 5.1 Positioning of test set during DF System Testing

1

2
4

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 B.T. 139-050 Rev. /

Table 5.3 DF System Functional Check

DF
MEASUREMENT DF SYSTEM BEARING
APPROXIMATE ERROR (°)
POSITION (°)
1 – 0° Rx1
2 – 90° Rx1
3 – 180° Rx1
4 – 270° Rx1

Table 5.4 Frequency range for guard receivers

Receiver Band Frequency Range
Guard Rx1 VHF Band 121.2 MHz -123.2 MHz 1
Guard Rx2 Maritime Band 155.6 MHz -158.5 MHz
Guard Rx3 UHF Band 241.2 MHz -245.1 MHz 1
Guard Rx4 Maritime Band 156.525 MHz (CH70) ONLY
Guard Rx5 SARSAT 406.025 (406.028) MHz ONLY

1
CAUTION: 121.5 MHz and 243.0 MHz are international distress frequencies. They should
not be used for test purposes without prior approval from the relevant ATC authority.

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 B.T. 139-050 Rev. /

5.6.5 HOMING OPERATION

1. Power ON the DF system (see 5.6.2)
2. Select Receiver 1 (the tunable receiver) to display the bearing data, using the
rotary knob or up / down navigation keys
3. Press the soft-key entitled “HMG” and verify the display changes to the Homing
screen
4. With reference to Figure 5.1 position the test set on the centre line
approximately 10 m in front the aircraft nose and switch ON the test set
5. Set the DF main receiver to the frequency to correspond to the selected test set
(see Table 5.4)
6. Verify that the indicator shows a typical bearing
7. Turn OFF the test set and verify on DF Controller the bearing display is frozen,
and the Age displayed is incremented
8. Verify on DF Controller that if the Age displayed exceeds 4 seconds, the
bearing is no longer highlighted, but the last known value is left shown (Note
that typically squelch will close before bearing capability is lost)
9. Switch ON the test set and verify that the indicator shows a typical bearing
10. Verify that pressing the SLW soft key the SLEW function is enabled and the
displayed bearing angle moves. Release SLW and verify the display returns to
show bearing to target only if a valid bearing is being detected

Page 36 of 36
Prego spedire a questo indirizzo: Data:
Please send to the following address: MODULO APPLICAZIONE BOLLETTINO TECNICO Date:
TECHNICAL BULLETIN COMPLIANCE FORM
AGUSTA S.p.A.
Numero:
CUSTOMER SUPPORT Number:
Via per Tornavento, 15
21019 Somma Lombardo (VA) - ITALY
Tel.: +39 0331 711100 Revisione:
Revision:
Fax: +39 0331 711397

Denominazione Cliente ed Indirizzo: Telefono:

Customer Name and Address: Telephone:

Fax:

Data Applicazione B.T.:

B.T. Compliance Date:

Modello Elicottero S/N Matricola Ore Totali Ore D.U.R.

Helicopter Model Tail Number Total Hours T.S.O.

Note:
Remarks:

Informazioni:
Information:

Al fine di gestire le varianti alla configurazione base, in relazione all’emissione del Bollettino Tecnico, preghiamo di voler compilare il presen-
te modulo in tutte le sue parti e spedirlo all’indirizzo sopra indicato. Si ringrazia 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.