### ERRATA CORRIGE

Please find here attached the page that have to be replaced in the basic Bollettino Tecnico

n° 1 0 9

- 136

.



### PAGE 5 “ STEP N° 3 ”

Was:

3. In a ccordance with the figure 1 remove the nuts MS21042L4 and replace it with nuts

NAS1805

- 4. Torq ue the nuts NAS1805

- 4 to 5.6 thru 7.9 N m “..... 9. N 6603

- 2 BOLT

Became:

3 In accordance with A109A/AII Maintenance Manual or A109C Maintenance Manual and the figures remove the nuts MS21042L4 and replace it with nuts NAS1805

- 4. Torque the nuts

NAS1805

- 4 to 5.6 thru 7.9 N m. “.....9. NAS1149C0332R WASHER

10. NAS6603

- 2 BOLTTRANSLATION OF



## BOLLETTINO TECNICO N° 

# 109

- 136

The technical content of this document is approved

under the authority of DOA nr EASA.21J.005. DATE September 20

, 2013

REV. A April 07 , 2011

Compliance with

this bollettino is:



# ALERT Page 1 of 10 SUBJECT: ONE TIME I NSPECTION OF THE NUT S MS21042L4 ON THE TAIL

ROTOR DRIVE SHAFT LINE AND SUBSEQUENT REPLACEMENT

WITH THE NUTS NAS1805

- 4

.

REASON: Provide the nec essary instructions to perform a one time visual

inspection for possible presence of cracks on nut s MS21042L4 installed

on the tail rotor drive shaft line (PART I) and subsequent replacement

with nuts NAS1805

- 4 (PART II)

.

HELICOPTERS AFFECTED:

All the Agusta A109 A, A109AII and A109C helicopters

.

COMPLIANCE:

PART I: At receipt of this Bollettino and before the next flight

PART II:

Within and not later than the next 1 0FH/30 days after the applicat ion of

the PART I of this Bollettino

.

DESCRIPTION:

On two in service AW109SP helicopters, during scheduled inspection on
the tail rotor drive shaft line, one nut MS21042L4 that connect the

Thomas c oupling with the splined adapter was found cracked

. The performed investigations have revealed that the crack rep orted on

the nut is due to a production deficiency (causing hydrogen embrittlement) from the standard nut supplier

. This Bollettino is issued in order to provide the necessary instructions to perform a one time visual inspection to verify the presence of cracks on

the n° 20 (A109A) or n°16 (A109AII/C) nuts MS21042L4 installed on the

tail rotor drive shaft line (PART I) and the necessary instructions toB.T. 109

- 136

Page 2 of 10 replace, on the tail rotor drive shaft line, the nuts MS21042L4 with the

nuts NAS1805

- 4 (PART II)

.

REQUIRED MANPOWER :

PART I: An estimated 2 manpower hours are required for compliance with this

Part of this Bollettino.

PART II: An estimated 16 manpower hours are required for compliance with this

Part of this Bollettino

WARRANTY :

Within the calendar terms mentioned at point “Compliance”, the parts required to apply the present Bollettino shall be supplied on a free of charge basis by AgustaWestland S.p.A. upon Customer’s request, with the exception for Consumable materials and Tool s; all the parts required after the “Compliance date” will be dispatched on charge basis for the

Customer.

Upon application of this Bollettino, destroy locally the removed parts

.

REQUIRED MATERIALS:

The following material is required to apply this Bolle ttino:

P/N DENOMINATION Q.TY NOTE

NAS1805

- 4 Nut 20 (1)

NAS1805

- 4 Nut 16 (2)

NOTE (1) Applicable for A109A (2) Applicable for A 109AII / A109C

SPECIAL TOOLS:

The following special tool could be required for compliance with this

Bollettino :

P/N DENOMINATION

Commercial Endoscope GE Inspection Tecnologies

Model: XL Go A3920 with 4.0 mm diameter and 2 m length probe (or equivalent)

WEIGHT AND BALANCE CHANGES:

N.A.

REFERENCES:

A109 A/AII Maintenance Manual

. A109C Maintenance Manual.

A109 A/AII Illustrated Parts Catalog

.B.T. 109

- 136

Page 3 of 10 A109C Illustrated Parts Catalog.

PUBLICATIONS AFFECTED:

A109A/AII Illustrated Parts Catalog. A109C Illustrated Parts Catalog.

COMPLIANCE INSTRUCTIONS:

PART I:

1. Prepare the helicopter on ground for a safe maintenance, disconnect any power supply , in accordance with the instructions given in the A109A/AII Maintenance Manual or A109C Maintenance

Manual

.

2. Gain access to the number 1 ÷ 4 drive shaft s (A109A) or to the

number 1÷3 drive shaft s (A109AII/C), in accordance with the instructions given in the A109A/AII Maintenance Manual or A109C

Maintenance Manual (Sections 65

- 31 and 52

- 0 0 (A109A/AII) or 65

- 10 and 06

- 40 (A109C) )

.

3. For A109A helicopters (See figure 1 and 2) :

3.1. Inspect the four nuts connecting the number 1 drive shaft with the adaptor splined for cracks.

NOTE

The use of a light source and a mirror is required. If any doubt remains, use an endoscope.

3.2. Inspect the four nuts connecting the number 2 drive shaft with the

number 1 drive shaft for cracks.

NOTE The use of a light source and a mirror is required. If any doubt remains, use an endoscope.

3.3. Inspect the four nuts connecting the number 3 drive shaft with the

number 2 drive shaft for cracks.

NOTE The use of a light source and a mirror is required. If any doubt remains, use an endoscope.

3.4. Inspect the four nuts connecting the number 4 drive shaft with the

number 3 drive shaft for cracks.

3.5. Inspect the four nuts connecting the number 4 drive shaft with the

ada ptor splined for cracks.B.T. 109

- 136

Page 4 of 10 NOTE The use of a light source, a mirror and an endoscope is required. (See figure 5 for the access point).

4

. For A109AII/C helicopters (See figure 3 and 4 ) :

4.1. Inspect the four nuts connecting the number 1 drive shaft with the adaptor splined for cracks.

NOTE

The use of a light source and a mirror is required. If any doubt remains, use an endoscope.

4.2. Inspect the four nuts connecting the number 2 drive shaft with the

number 1 drive shaft for cracks.

NOTE The use of a light source and a mirror is required. If any doubt remains, use an endoscope.

4.4. Inspect the four nuts connecting the number 3 drive shaft with the

number 2 drive shaft for cracks.

4 .5. Inspect the four n uts connecting the number 3 drive shaft with the adaptor splined for cracks.

NOTE

The use of a light source, a mirror and an endoscope is required. (See figure 5 for the access point).

5. If any crack is found, replace all the nut s MS21042L4 with the new NAS1805

- 4 nut s in accordance with the PART II of this Bollettino

.

6

. If no cracks are found proceed with the following steps.

7

. Remove all the tools and other items from the work area. Make sure

that the work area is clean.

8

. Install all the access panel s and close all the access doors removed/opened during point 2 in accordance with the inst ructions given in the A109A/AII Maintenance Manual or A109C Maintenance

Manual (Section 52

- 00 (A109A/AII) 06

- 40 (A109C) )

.

9

. Return the helicopter to a ready to flight condition.B.T. 109-136

Page 5 of 10 10. Record compliance with the PART I of this Bolle ttino in the helicopter log book.

PART II : 1 Prepare the helicopter on ground for a safe maint enance, disconnect any power supply, in accordance with the instructions given in the A109A/AII Maintenance Manual or A109C Maintenance

Manual .

2. Gain visual access to the number 1÷4 drive shaft (A109A) and to the number 1÷3 drive shaft (A109AII/C), in accordan ce with the instructions given in the A109A/AII Maintenance Man ual or A109C Maintenance Manual (Sections 65-31 and 52-00 (A109A /AII) or 65- 10 and 06-40 (A109C) ).

3. In accordance with the figure 1 remove the nuts MS21042L4 and replace it with nuts NAS1805-4. Torque the nuts NAS 1805-4 to 5.6

thru 7.9 N m.

NOTE 1

To avoid the disassembling of the Tail Rotor shaft is recommended to replace the nuts

interested one at a time.

NOTE 2 To perform the replacement of the above mentioned nuts, it may be necessary to remove part of the tail rotor drive shaft line, in accordance with the instructions given in the

A109A/AII Maintenance Manual or A109C Maintenance Manual (Section 52-00 (A109A/AII) 06-40 (A109C) ).

4. Remove all the tools and other items from the wo rk area. Make sure

that the work area is clean.

5. Install the access panel and close the access do ors previously removed/opened in accordance with the instructions given in the

A109A/AII Maintenance Manual or A109C Maintenance M anual

6. Return the helicopter to a ready to flight condi tion.

7. Record compliance with the PART II of this Bolle ttino in the helicopter log book.

8. Send the attached compliance form to the followi ng email box: Aw109.mbx@agustawestland.comB.T. 109

- 136

Page 5 of 10 10

. Record compliance with the PART I of this Bollettino in the helicopter log book.

PART II :
1 Prepare the helicopter on ground for a safe maintenance, disconnect any power supply, in accordance with the instructions given in the A109A/AII Maintenance Manual or A109C Maintenance

Manual

.

2. Gain visual access to the number 1÷ 4 drive shaft (A109A) a nd to the number 1÷3 drive shaft (A109AII/C), in accordance with the instructions given in the A109A/AII Maintenance Manual or A109C Maintenance Manual (Sections 65

- 31 and 52

- 00 (A109A/AII) or 65

- 10 and 06

- 40 (A109C) )

.

3. In accordance with A109A/AII Maintenance Manual or A109C

Maintenance Manual and the figure s remove the nuts MS21042L4 and replace it with nuts NAS1805

- 4. Torque the nuts NAS1805

- 4 to

5.6 thru 7.9 N m.

NOTE 1

T o avoid the disassembl ing of the T ail R otor shaft is recommended to replace the nuts

interested one at a time.

NOTE 2 To perform the replacement of the above
mentioned nuts, it may be necessary to remove part of the tail rotor drive shaft line, in accordance with the instructions given in the

A109A/AII Maintenance Manual or A109C

Maintenance Manual (Section 52

- 00 (A109A/AII) 06

- 40 (A109C) )

.

4. Remove all the tools and other items from the work area. Make sure

that the work area is clean.

5. Install the access panel and close the access doors previously removed/opened in ac cordance with the instructions given in the

A109A/AII Maintenance Manual or A109C Maintenance Manual

6. Return the helicopter to a ready to flight condition.

7. Record compliance with the PART II of this Bollettino in the helicopter log book.

8. Send the attached compliance form to the following email box: Aw109.mbx@agustawestland.comB.T. 109

- 136

Page 6 of 10 

# FIGURE 1

That figure is representative, for more details ref. to Pertinent Maintenance ManualB.T. 109

- 136

Page 7 of 10 

# FIGURE 2

That figure is representative, for more details ref. to Pertinent Maintenance ManualB.T. 109

- 136

Page 8 of 10 

# FIGURE 3

That figure is representative, for more details ref. to Pertinent Maintenance ManualB.T. 109

- 136

Page 9 of 10 

# FIGURE 4

That figure is representative, for more details ref. to Pertinent Maintenance ManualB.T. 109

- 136

Page 10 of 10 DETAIL A



# FIGURE 5

For ref. only ANote:

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.