### ERRATA CORRIGE

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

n°109S-055 .



### • PAGE 4 “STEP N° 3”

Was:

• 3. In accordance with the figure 1 and 2 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. N6603-2 BOLT

Became:

3. In accordance with 0B-A-AMP-00-XX Maintenance Pu blication and the figure 1 and 2 remove the nuts MS21042L4 and replace it with nuts NAS1805-4. Torque the nuts

NAS1805-4 to 5.6 thru 7.9 N m.

10. NAS6603-2 BOLT

# ALERT

TRA NSLATION OF



## BOL LETTINO TECNICO N° 

# 109S-055

The technical content of this document is approved

und er the authority of DOA nr EASA.21J.005. DATE September 20, 2013

REV. A April 07, 2011

Compliance with

this bollettino is:



# AL E RT Page 1 of 7 SUBJECT: ONE TIME INSPECTION OF THE NUTS MS21042L4 ON THE TAIL

ROTOR DRIVE SHAFT LINE AND SUBSEQUENT REPLACEMENT

WITH THE NUTS NAS1805-4.

REASON: Provide the necessary instructions to perform a one time visual

inspection for possible presence of cracks on nuts 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 A109S helicopters.

COM PLIANCE:

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

PART II: Within and not later than the next 10FH/30 days after the application 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 coupling with the splined adapter was found cracked. The performed investigations have revealed that the crack reported 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°16 nuts MS21042L4 installed on the tail rotor drive shaft lineB.T. 109S-055

Page 2 of 7 (PART I) and the necessary instructions to replace, on the tail rotor drive

shaft line, the nuts MS21042L4 with the nuts NAS180 5-4 (PART II).

REQUIRED MANPOWER:

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

Part of this Bollettino.

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

Part of this Bollettino

WARRANTY:

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

Customer.

Upon application of this Bollettino, destroy locall y the removed parts.

REQUIRED MATERIALS:

The following material may be required to apply thi s Bollettino:

P/N DENOMINATION Q.TY

NAS1805-4 Nut 16.

SPECIAL TOOLS:

The following special tool could be required for co mpliance 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:

0B-A-AMP-00-XX Maintenance Publication

0B-A-IPD-00-XX Illustrated Parts Data Publication

PUBLICATIONS AFFECTED:

0B-A-IPD-00-XX Illustrated Parts Data PublicationB.T. 109S-055

Page 3 of 7 COMPLIANCE INSTRUCTIONS:

(See figure 1 to 3)

PART I: 1. Prepare the helicopter on ground for a safe main tenance, disconnect any power supply, in accordance with the instructions given in the 0B-A-AMP-00-XX Maintenance Publication

.

2. Gain access to the number 1 drive shaft, the num ber 2 drive shaft and the number 3 drive shaft, in accordance with th e instructions given in the 0B-A-AMP-00-XX Maintenance Publication (Sections 65-10 and 06-40).

3. Inspect the four nuts connecting the number 1 d rive 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. Inspect the four nuts connecting the number 2 d rive 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.

5. Inspect the four nuts connecting the number 2 d rive shaft with

number 3 drive shaft for cracks.

6. Inspect the four nuts connecting the number 3 d rive shaft with the adaptor splined for cracks.

NOTE

The use of a light source, a mirror and an endoscope is required. (See figure 3 for the access point).

7. If any crack is found, replace all the nuts MS21 042L4 with the new

NAS1805-4 nuts in accordance with the PART II of th is Bollettino.

8. If no cracks are found proceed with the followin g steps.

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

that the work area is clean.

10. Install all the access panels and close all the access doors removed/opened during point 2 in accordance with th e instructionsB.T. 109S-055

Page 4 of 7 given in the 0B-A-AMP-00-X Maintenance Publication (Section 06-

40).

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

12. 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 0B-A-AMP-00-XX Maintenance Publication.

2. Gain access to the number 1 drive shaft, the number 2 drive shaft and the number 3 drive shaft, in accordance with the instructions given in the 0B-A-AMP-00-XX Maintenance Publication (Sections 65-10 and 06-40).

3. In accordance with the figure 1 and 2 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

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

0B-A-AMP-00-XX Maintenance Publication (Section65-10).

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 accordance with the instructions given in the

0B-A-AMP-00-XX Maintenance Publication

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. 109S-055

Page 4 of 7 given in the 0B-A-AMP-00-X Maintenance Publication (Section 06-

40).

11. Return the helicopter to a ready to flight cond ition.

12. 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 0B-A-AMP-00-XX Maintenance Publication

.

2. Gain access to the number 1 drive shaft, the num ber 2 drive shaft and the number 3 drive shaft, in accordance with th e instructions given in the 0B-A-AMP-00-XX Maintenance Publication (Sections 65-10 and 06-40).

3. In accordance with 0B-A-AMP-00-XX Maintenance Pu blication and the figure 1 and 2 remove the nuts MS21042L4 and re place it with nuts NAS1805-4. Torque the nuts NAS1805-4 to 5.6 th ru 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

0B-A-AMP-00-XX Maintenance Publication (Section65-10).

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

0B-A-AMP-00-XX Maintenance Publication

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. 109S-055

Page 5 of 7 

# FIGURE 1

0B-A-IPD-00-XX Illustrated Parts Data Publication S ection 65-10

TAIL ROTOR DRIVE SHAFT INSTL,FWD N°1 SPLINED

ADAPTER

MS21042L4 NUT x 2

N°1 THOMAS

COUPLING MS21042L4 NUT x 2

MS21042L4 NUT x 2 N°2 THOMAS

COUPLING N°2 SPLINED

ADAPTER MS21042L4 NUT x 2

N°3 SPLINED

ADAPTER

MS21042L4 NUT x 2

N°3 THOMAS

COUPLING

MS21042L4 NUT x 2B.T. 109S-055

Page 6 of 7 

# FIGURE 2

0B-A-IPD-00-XX Illustrated Parts Data Publication

Section 65-10 DRIVE SHAFT AND 90 DEGREE GEARBOX INS TL N°4 THOMAS

COUPLING

N°4 SPLINED

ADAPTER MS21042L4 NUT x 2

MS21042 L4 NUT x 2

ENDOSCOPE

ACCESS POINTB.T. 109S-055

Page 7 of 7 DETAIL A



# FIGURE 3

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.