## BOLLETTINO TECNICO N° 

# 139

- 19 5

The technical content of this document is approved under the authority of DOA nr. EASA.21J.005 DATE Oc tober 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 c onfigura tion s

. 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.

## B.T. 139

- 1 95 Rev. B

P age 2 of 8 NOTE

Part II of this Bollettino i s not applicable to helicopters that have already complied with Bollettino

no. 139

- 1 59.
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 3G5309P 01812

.

COMPLIANCE:
Part I: daily.
Part II: within 2 5 flight hours from the last inspection as for BT 139

- 193 and 139

- 194 or within 1 wee k from the receipt of this Bollettino whichever occurs later and then
every 2 5 flight hours

. Part I I I: within 5 0 flight hours from the last inspection as for BT 139

- 193 and 193

- 194 and then every 5 0 flight hours

.

DESCRIPTION : s cope of this Bollettino is t o apply prudentially a tighter inspection
schedule on specific tailboom configurations based on the finding coming from the inspection required from B T no. 139

- 193 and no. 139

- 194. The inspection schedule consists of t hree parts. A daily General Visual Ins pection (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

- 1 9 5 Rev. B

P age 3 of 8 REQUIRED MANPOWER: t he following estimated manpower hours are required for compliance with this Bollettino : Part I: N.A.
Part II: thirty (30) minutes

. Part I I I: two (2 ) hours.
Man

- hours are based on hands

- on time and may vary with personnel and facilities
available

WARRANTY: N.A.

REQUIR ED 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 A FFECTED: N.A.

## B.T. 139

- 1 95 Rev. B

P age 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 fuselag e 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 figur es 1, do the inspection of the tail assy for debondi ng, 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 sin gle disbond is 32 0 mm 2 in AREA 3 and
150 mm 2 in 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 r ecord for compliance of Part I of
this bollettino.

## B.T. 139

- 1 9 5 Rev. B

P age 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 su pply.
2. G et 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

pre vent 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
, d o 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 , inspec t 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 mm 2 in AREA 3 and
150 mm 2 in 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

- 1 95 Rev. B

P age 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 (s ee DM n o. 39

- A

- 53

- 40

- 00

- 00A

- 2 86J

- 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 , t he maximum permitted size for a single disbond is 320

mm 2 in AREA 3 and 150 mm 2 in 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

- 1 9 5 Rev. B

P age 7 of 8 Figure 1

## B.T. 139

- 1 95 Rev. B

P age 8 of 8 Figure 2Note: 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.** CUSTOMER SUPPORT & SERVICES - ITALY PRODUCT SUPPORT ENGINEERING DPT. Via del Gregge, 100 2101 5 Lonate Pozzolo (VA) - I T ALY T el

. : +39 0331 664600 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.