### ERRATA CORRIGE

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

n° 1 0 9 K

- 58

.



### 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. N 6603

- 2 BOLT

Became:

3 In accordance with A109K2 Maintenance Manual 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 “ .....9. NAS1149C0332R WASHER

10. NAS6603

- 2 BOLTTRANSLATION OF



## BOLLETTINO TECNICO N° 

# 109 K- 58

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 7 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 K2 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 reporte d 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. 109 K

- 58

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 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 may be required to apply this Bo llettino:

P/N DENOMINATION Q.TY

NAS1805

- 4 Nut 16

.

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:

A109K2 Maintenance Manual

. A109K2 Illustrated Parts Catalog

PUBLICATIONS AFFECTED:

A109K2 Illustrated Parts CatalogB.T. 109 K

- 58

Page 3 of 7 COMPLIANCE INSTRUCTIONS:

(See figure 1 to 3 )

PART I:

1. Prepare the helicopter on ground for a safe maintenance, disconnect any power supply , in accordance with the instructions given in the A109K2 Maintenance Manual

.

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 A109K2 Maintenance Manual (Sections 65

- 1 0 and 06

- 40 )

.

3. 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. 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.

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

number 3 drive shaft for cracks.

6. Inspect the four nuts connecting the number 3 drive shaft with the adaptor sp lined 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 MS21042L4 with the new

NAS1805

- 4 nuts in accordance with the PART II of this Boll ettino.

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

9. Remove all the tools and other items from the work 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 the instructionsB.T. 109 K

- 58

Page 4 of 7 given in the A109K2 Maintenance Manual (Sections 65

- 10 and 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 A109K2 Maintenance Manual

.

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 A109K2 Maintenance Manual ( Sections 65

- 1 0 and 06

- 40 ).

3. In accordance with the figure 1 and 2 remove the nut s 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

A109K2 Maintenance Manual ( Section 65

- 1 0 ).

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

that the work area is clean.

5. Install all the access panels and close all the access doors removed/opened during point 2 in accordance with the instructions given in the A109K2 Maintenance Manual (Sections 65

- 10 and 06

- 4 0).

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 K

- 58

Page 4 of 7 given in the A109K2 Maintenance Manual (Sections 65

- 10 and 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 A109K2 Maintenance Manual

.

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 A109K2 Maintenance Manual ( Sections 65

- 1 0 and 06

- 40 ).

3. In accordance with A109K2 Maintenance Manual 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.

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

A109K2 Maintenance Manual ( Section 65

- 1 0 ).

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

that the work area is clean.

5. Install all the access panels and close all the access doors removed/opened during point 2 in accordance with the instructions given in the A109K2 Maintenance Manual (Sections 65

- 10 and 06

- 40).

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 K

- 58

Page 5 of 7 

# FIGURE 1

r ef. A109K2 Illustrated Parts Catalog

Section 65

- 10 TAIL ROTOR DRIVE SHAFT INSTL,FWD N°1 SPLINED

ADAPTER

MS21042 L4 NUT x 2

N°1 THOMAS

COUPLING MS21042 L4 NUT x 2

MS21042 L4 NUT x 2 N°2 THOMAS

COUPLING N°2 SPLINED

ADAPTER MS21042 L4 NUT x 2

N° 3 SPLINED

ADAPTER

MS21042 L4 NUT x 2

N° 3 THOMAS

COUPLING

MS21042 L4 NUT x 2B.T. 109 K

- 58

Page 6 of 7 

# FIGURE 2

ref. A109K2 Illustrated Parts Catalog

Section 65

- 10 DRIVE SHAFT AND 90 DEGREE GEARBOX INSTL N° 4 THOMAS

COUPLING

N° 4 SPLINED

ADAPTER MS21042 L4 NUT x 2

MS21042 L4 NUT x 2B.T. 109 K

- 58

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.