# ALERT

TRANSLATION OF 

## BOLLETTINO TECNICO N° 

# 109S

- 15

The technical content of this document is approved
under the au thority of DOA nr EASA.21J.005. DATE July 12, 2007

REV. xxxxxxx

Compliance with this bollettino is:



# ALERT Page 1 of 8 SUBJECT: INSPECTION AND REWORK OF THE LOWER SEMICHANNEL

ASSEMBLIES P/N 109

- 0642

- 01

- 171 OF THE FORWARD FIREWALL.

REASON: P erform an “una tantum” (one time) inspection on the two subject lower semi

- channel assemblies for the presence of the metallic spacers P/N 109

- 0642

- 01

- 195, and if present, perform an inspection on the main drive shaft, check the spacers for correct fixation and check the gaskets P/N 109

- 0642

- 01

- 169 for correct seating.

HELICOPTERS AFFECTED:

All the Agusta A109S helicopters up to S/N 22034 included, except for the S/Ns 22026 and 22033.

COMPLIANCE:

Within the next 20 (twenty) flight hours after the receipt of this Bollettino and however within and not later than September 30, 2007.

DESCRIPTION:

Cases of mechanical damage of the main drive shaft P/N 109

- 0415

- 06

- 103 have been reported on some A109 series helicopters

. The resultant investigation identified the reason of the malfunction in the missing fixing rivets of the metallic spacers P/N 109

- 0642

- 01

- 195 to the lower semichannel assy P/N 109

- 0642

- 01

- 171 of the forward firewall. The lack of the rivets has allowed the metallic spacers to rotate and come into contact with the main drive shaft

. Not all the helicopters are equipped with the metallic space rs P/N 109

- 0642

- 01

- 195 on the lower semichannel assy P/N 109

- 0642

- 01

- 171, in that the spacers are installed, if required, to guarantee a clearance between the main drive shafts and the semichannels.B.T. 109S

- 15

Page 2 of 8 Moreover, durin g the investigation, cases of wrong positioning of the

gaskets P/N 109

- 0642

- 01

- 169 have been reported. This Bollettino provides the instructions to perform an “una tantum” (one time) inspection on the two lower semichannel for the presence of the metallic spacers. If installed, it is necessary to perform an inspection on the main drive shaft in the semichannels area for damage, correct fixation of the spacer on the semichannels and the gaskets for correct seating

.
REQUIRED MANPOWER :

An estimated 3 (three) manpower hours are required for compliance with this Bollettino.

WARRANTY:

The parts required to apply this Bollettino shall be supplied on a free of charge basis, except the consumable materials, by Agusta upon request. Customers are requested to inform Agusta

– Warranty Administration

– by means of the attached Technical Bulletin Compliance Form the Bollettino implementation.

REQUIRED MATERIALS:

The following materials could be required for compliance with this Bollettino :

P/N DENOMINATION Q.TY MS204 27M3

- 5
or: Rivet 4 MS20426T3

- 5 A298A04TW02 Rivet 4

In addition the following consumable materials are necessary:

SPECIFICATION DENOMINATION Q.TY 199

- 05

- 107 Adhesive EC776 A.R. Type II Class 5 (cod. 500204274) TT -M- 261 Methylethylketone A.R. (cod. 505407211)

SPECIAL TOOLS:

N.A.

WEIGHT AND BALANCE CHANGES:

N.A.

REFERENCES:

A109S Air Vehicle Maintenance Publication.B.T. 109S

- 15

Page 3 of 8 PUBLICATIONS AFFECTED:

A109S Air Vehicle Maintenance Publication

.
COMPLIANCE INSTRUCTIONS:

GENERAL NOTES ÿ Unless otherwise specified retain all parts that will be removed in following operations. Replace damaged hardware.

ÿ After drilling remove all swarf and sharp edges and if required restore the finishing

.
ÿ All dimensions are in mm

. ( See figures 1 and 2 )

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

2. Open the left engine cowling D22 and the right engine cowling D28, in accordance with the instructions given in the A109S Air Vehicle Maintenance Publication.

NOTE The followin

g inspection procedure is applicable for both lower semichannel assemblies P/N 109

- 0642

- 01

- 171, right side and left side of the helicopter.

3. With reference to figures 1 and 2, verify if between the lower semichannel assy P/N 109

- 0642

- 01

- 171 and the door as sy P/N 109

- 0642

- 01

- 181 and

- 182 upper semichannel, the two metallic spacers P/N 109

- 0642

- 01

- 195 are installed (semichannel left side and right side).

NOTE

To verify the metallic spacers P/N 109

- 0642

- 01

- 195 presence use a mirror and a suitable light source.

3.1 If between the lower semichannel and the upper semichannel metallic spacers P/N 109

- 0642

- 01

- 195 are not installed, no corrective action is necessary. Perform Step 6 and subsequent of this Bollettino.B.T. 109S

- 15

Page 4 of 8 3.2 If between the low er semichannel and the upper semichannel metallic spacers P/N 109

- 0642

- 01

- 195 are installed, proceed in accordance with Step 4 and subsequent of this Bollettino.

4. Perform the inspection on the main drive shaft, the metallic spacers for correct fixation on the semichannels and the gaskets for correct seating as follows:

4.1 In accordance with figures 1 and 2, from the forward firewall assy P/N 109

- 0642

- 01

- 101, acting on the relevant fixing hardware, remove the lower semichannel assy P/N 109

- 0642

- 01

- 171.

N OTE 1 To facilitate the lower semichannel assy P/N 109

- 0642

- 01

- 171 removal (helicopter right side and left side), the removal of the left engine cowling D22 and the right engine cowling D28, in accordance with the instructions given in the A109S Air Vehicl e Maintenance Publication is recommended.

NOTE 2 Take note of the installation position and side of the spacers and gaskets on the semichannel, in that the parts shall be reinstalled in their original position.

4.2 If present, remove the fixing rivets of the metallic spacers P/N 109

- 0642

- 01

- 195 to the lower semichannel assy P/N 109

- 0642

- 01

- 171.

4.3 From the lower semichannel assy P/N 109

- 0642

- 01

- 171 remove the gaskets P/N 109

- 0642

- 01

- 169 and the metallic spacers P/N 109

- 0642

- 01

- 195.

NOTE 1

During this operation pay particular attention to avoid spacers and gaskets damage.

NOTE 2 If two or more stacked gaskets are present, they must be retained for reuse.

4.4 Remove the old adhesive from the parts using cheesecloth moist ened in Methylethylketone.B.T. 109S

- 15

Page 5 of 8 4.5 If not present, in accordance with figure 2, perform the two Ø 2,5 mm holes through the metallic spacers P/N 109

- 0642

- 01

- 195 and the lower semichannel assy P/N 109

- 0642

- 01

- 171, taking care not to protrude stick out the meta llic spacer towards the inside of the semichannel.

NOTE If in the metallic spacers the holes are present, use them as template to drill the lower semichannel.

4.6 In accordance with figure 2, on the lower semichannel assy P/N 109

- 0642

- 01

- 171 insta ll the n. 1+1 metallic spacers P/N 109

- 0642

- 01

- 195 using two MS20427M3 rivets or two MS20426T3 rivets or two rivets P/N A298A04TW02.

CAUTION Install the spacers on the semichannel in the original position and side, as noted at step 4.1.

4.7 In accordance with figure 2, on the n. 1+1 metallic spacers P/N 109

- 0642

- 01

- 195 bond the n. 1+1 gaskets P/N 109

- 0642

- 01

- 169 using adhesive EC776.

CAUTION If at step 4.3 stacked gaskets have been removed, bond them over the m etallic spacers.

4.8 Inspect the main drive shaft tube in the semichannels area for damage (nicks and/or scratches)

.
NOTE In case the removal of the main drive shaft P/N 109

- 0415

- 06

- 103 shall be necessary reinstall the lower semichannel assy P/N 109

- 0642

- 01

- 171, before to start with the removal operations in accordance with the instructions given in the A109S Air Vehicle Maintenance Publication.

4.9 In case damages are reported, the main drive shaft shall be removed from the helicopter, in accord ance with the instructions given in the A109S Air Vehicle Maintenance Publication, for the damages depth measurement.B.T. 109S

- 15

Page 6 of 8 CAUTION In case the damages depth is above to the value reported in the A109S Air Vehicle Maintenance Publication, remove the shaft from the service and replace it with one of the same P/N.

4.10 If removed, reinstall the main drive shaft on the helicopter, in accordance with the instructions given in the A109S Air Vehicle Maintenance Publication.

4.11. If not already performed, reinstall the lower semichannel assy P/N 109

- 0642

- 01

- 171 on the forward firewall assy P/N 109

- 0642

- 01

- 101, using the previously removed fixing hardware.

4.12. Using a feeler gauge verify that the minimum clearance around the main drive shaft and the upper and low er semichannels is not less than 4,0 mm.

CAUTION If in one or more places the minimum distance should be less than 4,0 mm immediately contact the Agusta Customer Support.

5. If removed, reinstall the left engine cowling D22 and the right engine cowling D28 , in accordance with the instructions given in the A109S Air Vehicle Maintenance Publication.

6. Return the helicopter in ready to flight condition

.

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

.Note: 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.**
**CU S**  **TOMER S**  **U PP**  **O RT**  Via per Torna v en t o, 15 21019 Som m a Lombardo (VA) - I T ALY T el

. : +39 0331 711100 Fa x : +39 0331 711397

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.