TRANSLATION OF



## BOLLETTINO TECNICO N° 

# 109K- 53

The technical content of this document is approved under the authority of DOA nr EASA.21J.005. DATE December 18 , 2009

REV. ,

Compliance with this bulletin is:

Page 1 of 7 SUBJECT: INSPECTION OF THE MAIN ROTOR SCISSOR FITTING ASSY

P/N 109-0110-67 FIXING BOLTS P/N 109-0101- 78 -5.

REASON: Perform a “ one-time ” inspection of the subject bolts to verify the presence of two washers under the head of each bolt and provide the instructions to restore the correct installation.

HELICOPTERS AFFECTED:

All the main rotor hub assy P/N 109

- 0101

- 01 installed on the Agusta A109K2 helicop ters or eventually in stock

.
COMPLIANCE:

PART I^: Within the next 5 flight hours after the receipt of this Bollettino.

PART II^: Within 25 flight hours after the compliance with PART I^ and however within and not later than April 30, 2010.

DESCRIPTION:

A case of fracture of two of the three bolts P/N 109-0101- 78 -5 fixing the main rotor scissor fitting assy P/N 109-0110- 67 has been reported in flight on an A1 09 K2 helicopter. The occurrence did not cause harm to the occupants nor damage to the helicopter. The investigations revealed that the malfunction was caused by incorrect information contained in the technical publications. This Bollettino is issued in order to provide the necessary instructions to perform a “ one-time ” inspection to verify the correct installation of the main rotor scissor fitting assy P/N 109-0110-67, that includes the installation of two washers under the head of each bolt P/N 109-0101- 78 -5 (PART I^) and, if necessary, to restore the designB.T. 109K- 53

Page 2 of 7 conditions by replacing the bolts P/N 109-0101- 78 -5 that were not

installed following the correct sequence (PART II^).

REQUIRED MANPOWER:

The following estimated manpower hours are required for compliance with this Bollettino: PART I^: Negligible; PART II^: 3 (three ).

WARRANTY:

The parts required to apply the present Bollettino shall be supplied on a free of charge basis by Agusta upon request, except for consumable materials. Upon application of this Bollettino, Customers are requested to submit to Agusta Warranty Administration the Technical Bulletin Compliance form attached to this Bulletin duly completed in all its parts.

REQUIRED MATERIALS:

PART I^: N.A.

PART II^: The following materials are required for compliance with PART II^ of this Bollettino:

P/N DENOMINATION Q.TY 109 -0101- 78 -5 Bolt 3 NAS1149C0463R Washer 3 NAS1149C0432R Washer 3

In addition the following consumable materials are necessary:

SPECIFICATION DENOMINATION Q.TY MS 20995C32 Lockwire A.R. MIL-PRF-16173 Corrosion preventive compound A.R. GR 1 CL 2 (cod. 999999999000000191 )

SPECIAL TOOLS:

N.A.

WEIGHT AND BALANCE CHANGES:

N.A.

REFERENCES:

A109K2 Maintenance Manual.

PUBLICATIONS AFFECTED:

 A109K2 Maintenance Manual;  A109K2 Overhaul Manual.B.T. 109 K

- 53

Page 3 of 7 COMPLIANCE INSTRCTIONS:

PART I^: ( See figur e 1 )

1. Prepare the helicopter on ground for a safe maintenance, disconnect any power supply

.

2. With reference to figure 1, gain access to the main rotor hub and verify that under the head of the three fixing bolts P/N 109

- 0101

- 78

- 5 of the main rotor scissor fitting assy P/N 109

- 0110

- 67 two washers are installed

.

2.1 If for each bolt two washers are installed, p erform the step 3

. and 4

.

NOTE In this case the compliance with PART II^ of this Bollettino is not required.

2.2 Even if under the head of only one bolt a single washer is installed, perform the PART II^ within the compliance limits of this Bollettino.

3. Return the helicopter to a ready to flight condition

.

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

.

PART II^: (See figures 1 and 2 )

1. Prepare the helicopter on ground for a safe maintenance, disconnect any power supply

.

2. With reference to figures 1 and 2, proceed with the removal of three bolts P/N 109

- 0101

- 78

- 5 as follows :

2.1. With reference to the A109K2 Maintenance Manual , unhook the four springs P/N 109

- 0101

- 56 and the four springs P/N 109

- 0101

- 57 from the half cover assy P/N 109

- 0101

- 98.

2.2. With reference to the A109K2 Maintenance Manual , disconnect the rotating half scissor assy P/N 109

- 8110

- 16 from the main rotor scissor fitting assy P/N 109

- 0110

- 67.B.T. 109K- 53

Page 4 of 7 NOTE To remove the sleeve inside the rotating half scissor assy P/N 109-8110-16, use a suitable aluminum drift.

2.3. Cut the lockwire and remove the three bolts P/N 109-0101- 78

- 5 with the relevant washers

, and the main rotor scissor fitting assy P/N 109-0110- 67.

2.4. Cut the lockwire and remove the two bolts P/N 109-0101- 78

- 3 with the relevant washers

, the spring holder bracket P/N 109-0104-13 and the half cover assy P/N 109-0101-98.

3. With reference to figures 1 and 2, proceed with the reassembly of the parts previously removed from the main rotor hub as follows:

NOTE Apply a light coat of corrosion preventive compound MIL-PRF-16173 on the mating surfaces and on the bolts un th readed st em

. 3.1. Reinstall the half cover assy P/N 109-0101-98 and the main rotor scissor fitting assy P/N 109-0110-67 by means of three new bolts P/N 109-0101- 78 -5, three new washers NAS1149C0463R (nominal thickness 1.5 mm) and three new washers NAS1149C0432R (nominal thickness 0.8 mm) under the bolts head (ref. figure 1).

3.2. Reinstall the spring holder bracket P/N 109-0104-13 by means of the previously removed two bolts P/N 109-0101- 78

- 3 with two washers AN960C416 or NAS1149C0463R and two washers AN960C416L or NAS1149C0432R under the bolts head (r ef. figure 1).

3.3. Torque 7.8 to 9.8 Nm the three bolts P/N 109- 0101

- 78 -5 and the two bolts P/N 109-0101- 78

- 3 and secure them with lockwire MS20995C32.

NOTE Apply a light coat of corrosion preventive compound MIL-PRF-16173 on the head of the installed bolts and on the washers.

3.4. With reference to the A109K2 Maintenance Manual, reconnect the rotating half scissor assy P/N 109- 8110

- 16 to the main rotor scissor fitting assy P/N 109-0110- 67.B.T. 109 K

- 53

Page 5 of 7 3.5. With reference to the A109K2 Maintenance Manual

, connect the four springs P/N 109

- 0101

- 56 and the four springs P/N 109

- 0101

- 57 to the half cover assy P/N 109

- 0101

- 98.

4. Return the helicopter to a ready to flight condition

.

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

.B.T. 109 K

- 53

Page 6 of 7 

# FIGURE 1B.T. 109 K

- 53

Page 7 of 7 

# 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.