BOLLETTINO TECNICO N° 139-195 

The technical content of this document is approved 

under the authority of DOA nr. EASA.21J.005 

DATE October 27, 2009

REV. B - February 2, 2010

Compliance with

this bulletin is: 

Page 1 of 8 

SUBJECT: TAIL ASSY INSPECTIONS 

REASON: to implement a tighter schedule inspection on specific tailboom configurations.

NOTE

This Bollettino supersedes BT no. 139-193 and BT 

no. 139-194. 

HELICOPTERS AFFECTED:

Part I and III: all AB139/AW139 helicopters equipped with following tail assembly P/N: 

 3G5350A00132; 

 3G5350A00133; 

 3G5350A00134; 

 3G5350A00135. 

Part II: AB139/AW139 helicopters equipped with following tail assembly P/N: 

 3G5350A00132; 

 3G5350A00133; 

 3G5350A00134 up to S/N A7/109 for short nose configuration; 

up to S/N A7/063 for long nose configuration.

MANDATORY

An appropriate entry should be made in the aircraft log book upon accomplishment.

If owner ship of air c raft has changed, please, forward to new owner.

An Company

Via Giovanni Agusta, 520

21017 Cascina Costa di Samarate (VA) Italy

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

ALERT

ALERT
B.T. 139-195 Rev. B

Page 2 of 8

NOTE

Part II of this Bollettino is not applicable to 

helicopters that have already complied with Bollettino

no. 139-159.

NOTE

This Bollettino is not applicable to helicopters that 

have already complied with Bollettino no. 139-200 or 

that are equipped with Tailboom Reinforcement 

Structural Retro-Modification P/N 3G5309P01812.

COMPLIANCE:

Part I: daily.

Part II: within 25 flight hours from the last inspection as for BT 139-193 and 139-194 or 

within 1 week from the receipt of this Bollettino whichever occurs later and then 

every 25 flight hours.

Part III: within 50 flight hours from the last inspection as for BT 139-193 and 193-194

and then every 50 flight hours.

DESCRIPTION: scope of this Bollettino is to apply prudentially a tighter inspection 

schedule on specific tailboom configurations based on the finding coming from the 

inspection required from BT no. 139-193 and no. 139-194.

The inspection schedule consists of three parts. A daily General Visual Inspection 

(Part I of the Bollettino) is aimed at spotting evident local outer panel skin bulgings 

and/or deformations on the RHS of the tailboom. Then a more frequent tapping 

check (Part II of the Bollettino) is required on two specific areas (marked as Area 3 

and Area 5 in previous instructions on this subject) located on the RHS for tailbooms 

with nomex sandwich.

Part III retains instead the 50 FH tapping check previously required by Bollettino no. 

139-193 and no. 139-194.
B.T. 139-195 Rev. B

Page 3 of 8

REQUIRED MANPOWER: the following estimated manpower hours are required for 

compliance with this Bollettino:

Part I: N.A.

Part II: thirty (30) minutes.

Part III:two (2) hours.

Man-hours are based on hands-on time and may vary with personnel and facilities 

available

WARRANTY: N.A.

REQUIRED MATERIALS: N.A.

SPECIAL TOOLS: the following special tools are necessary to accomplish this 

bollettino:

P/N DESCRIPTION Q.TY

(*) 109-3101-58-1 Hammer, tapping (GF-05-00) Alt.

109-3101-58-2 Hammer, tapping (GF-06-00) 1

2004-5007-B Platform (GG-07-00) 1

Local supply Strong light 1

Note: (*) used as an alternative to hammer (GF-06-00)

WEIGHT AND BALANCE CHANGES: N.A.

REFERENCES:

 AW139 Illustrated Tools and Equipment Publication (ITEP)

 AW139 Aircraft Maintenance Publication (AMP)

PUBLICATIONS AFFECTED: N.A.
B.T. 139-195 Rev. B

Page 4 of 8

COMPLIANCE INSTRUCTIONS:

Part I:

1. Get access to the tail assy on the RH side of the aircraft.

2. Perform a general visual inspection of the tail assy panels within touching distance 

and using a light source for evident local outer skin bulging and/or deformations

3. If you find evident bulging on the panel skin, perform a tapping check as follows in 

order to better identify the area interested by the defects:

3.1 Put the Platform (GG-07-00) or an approved alternative adjacent to the side of 

the fuselage to help you at step 3.2, if required.

NOTE

This inspection can be accomplished only by 

personnel qualified to perform a tapping check.

The tapping frequency must make a continuous tone 

to help identify the tone change immediately.

3.2 With reference to figures 1, do the inspection of the tail assy for debonding, 

using the Hammer (GF-06-00) in the area adjacent to the defect found:

CAUTION

Be careful when you do the tapping operation to 

prevent damage to the panels surface.

3.3 The maximum permitted size for a single disbond is 320 mm2in AREA 3 and 

150 mm2in any other AREA.

4. If you find signs of debonding that are not within the limits mentioned at step 3, mark 

the debonded areas for identification and contact Product Support Engineering 

(aw139.mbx@agustawestland.com)

5. Remove the platform from the fuselage side and record for compliance of Part I of 

this bollettino.
B.T. 139-195 Rev. B

Page 5 of 8

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.

2. Get access to the tail assy on the RH side of the aircraft.

3. Put the Platform (GG-07-00) or an approved alternative adjacent to the RH side of 

the fuselage to help you at step 4, if required.

CAUTION

Be careful when you do the tapping operation to 

prevent damage to the panels surface.

NOTE

This inspection can be accomplished only by 

personnel qualified to perform a tapping check.

The tapping frequency must make a continuous tone 

to help identify the tone change immediately.

4. With reference to figure 2, do the inspection of the tail assy for debonding, using the 

Hammer listed in the special tools section of this Bollettino:

NOTE

Inspection must be performed between indicated 

STA on the whole panel extension in BL and WL.

4.1 With reference to figure 2, inspect panel areas in the following sequence:

- Area 5;

- Area 3, except for the longeron (3) area

4.2 The maximum permitted size for a single disbond is 320 mm2in AREA 3 and 

150 mm2in AREA 5.

4.3 The minimum permitted spacing distance between disbond boundaries is three

times the largest disbond dimension measured on a line between the centres of 

the two disbonds. See figure 2 to help you measuring debonding spacing.

4.4 No debonding is permitted within 3.0 mm from any bond joint edge.

5. If you find signs of debonding that are within the limits mentioned at step 4, do as 

follows:

5.1 Remove the platform from the fuselage side, if required, and go to step 7.
B.T. 139-195 Rev. B

Page 6 of 8

6. If you find signs of debonding that are not within the limits mentioned at step 4, mark 

the debonded areas for identification and contact Product Support Engineering 

(aw139.mbx@agustawestland.com).

7. Record for compliance of Part II of this bollettino.

Part III:

1. Prepare the helicopter for a safe ground maintenance. Disconnect the battery and all 

the electrical power sources and/or the external power supply.

CAUTION

During the inspection at following step 2, remove the 

tail rotor shaft cowling assy to better access to the 

panel areas.

2. Perform the detailed inspection of the tail panels according to AMP (see DM no. 39-

A-53-40-00-00A-286J-A).

NOTE

This inspection can be accomplished only by 

personnel qualified to perform a tapping check.

The tapping frequency must make a continuous tone 

to help identify the tone change immediately.

2.1.With reference to figure 2, the maximum permitted size for a single disbond is 320 

mm2in AREA 3 and 150 mm2in AREA 1, 2, 4 and 5.

3. If you find signs of debonding that are not within the mentioned limits, mark the 

debonded areas for identification and contact Product Support Engineering 

(aw139.mbx@agustawestland.com) before next flight.

4. Record for compliance of Part III of this bollettino.
B.T. 139-195 Rev. B

Page 7 of 8

Figure 1
B.T. 139-195 Rev. B

Page 8 of 8

Figure 2
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 presente 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.

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. 

CUSTOMER SUPPORT & SERVICES - ITALY

PRODUCT SUPPORT ENGINEERING DPT.

Via del Gregge, 100

21015 Lonate Pozzolo (VA) - ITALY 

Tel.: +39 0331 664600

Fax: +39 0331 664684

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.