# Agusta Bollettino Tecnico 109EP-79: No revision named - Rights: © Leonardo S.p.A. Filed by the FAA in regulations.gov docket FAA-2012-0501; AD 2012-23-02 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Agusta Bollettino Tecnico 109EP-79](https://openairdocs.org/service-documents/leonardo/109ep-79.md) - Title as filed: U.S. DOT/FAA - Agusta Service Information - 1 - Pages: 10 - PDF: https://openairdocs.org/files/sha256/b4/1e/b41eff2b676d0d2ae6930015b4275aa2060df09b6513921d512da94915b13f44 - Page: https://openairdocs.org/service-documents/leonardo/109ep-79/file/b41eff2b676d ## Text Some pages are OCR from a scan. OCR can misread letters and numbers. Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 ALERT TRANSLATION OF BOLLETTINO TECNICO N° 109EP-79 The technical content of this document is approved under the authority of DOA nr EASA.21J.005. DATE July 12, 2007 REV. xxxxxxx Compliance with this bollettino is: ALERT Page 1 di 8 SUBJECT:INSPECTION AND REWORK OF THE LOWER SEMICHANNEL ASSEMBLIES P/N 109-0641-10-213 OR P/N 109-0642-01-171 OF THE FORWARD FIREWALL. REASON: Perform 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 109-0641-45-217 or P/N 109-0642-01-169 for correct seating. HELICOPTERS AFFECTED: All the Agusta A109E helicopters up to S/N 11694 included, except for the S/Ns 11633 and 11634. 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 109-0641-10-213 or 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. ### Page 2 B.T. 109EP-79 Page 2 of 8 Not all the helicopters are equipped with the metallic spacers P/N 109-0642-01- 195 on the lower semichannel assy P/N 109-0641-10-213 or 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. Moreover, during the investigation, cases of wrong positioning of the gaskets P/N 109-0641-45-217 or P/N 109-0642-01-169 have been reported. This Bollettino provides the instructi ons 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 MS20427M3-5 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. ### Page 3 B.T. 109EP-79 Page 3 of 8 WEIGHT AND BALANCE CHANGES: N.A. REFERENCES: A109E Maintenance Manual. PUBLICATIONS AFFECTED: A109E Maintenance Manual. COMPLIANCE INSTRUCTIONS: GENERAL NOTES Ø Unless otherwise specified retain all parts that will be removed in following operations. Replace damaged hardware. Ø After drilling remove all swarf and sharp edges and if required restore the finishing. Ø 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 P22 and the right engine cowling P19, in accordance with the instruc tions given in the A109E Maintenance Manual. NOTE The following inspection procedure is applicable for both lower semichannel assemblies P/N 109-0641-10-213 (or 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 109-0641-10-213 (or P/N 109-0642-01- 171) and the door assy P/N 109-0641-45-173 and –205 (or 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). ### Page 4 B.T. 109EP-79 Page 4 of 8 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. 3.2 If between the lower 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 109-0641-45-201 (or P/N 109-0642-01-101), acting on the relevant fixing hardware, remove the lower semichannel assy P/N 109-0641-10-213 (or P/N 109-0642-01-171). NOTE 1 To facilitate the lower semichannel assy P/N 109-0641-10-213 (or P/N 109-0642-01- 171) removal (helicopter right side and left side), the removal of the left engine cowling P22 and the right engine cowling P19, in accordance with the instructions given in the A109E Maintenance Manual is recommended. NOTE 2 Take no te 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 109-0641-10-213 (or P/N 109-0642-01-171). 4.3 From the lower semichannel assy P/N 109-0641-10-213 (or P/N 109-0642-01-171) remove the gaskets P/N 109-0641-45-217 (or P/N 109-0642-01-169) and the metallic spacers P/N 109-0642-01- 195. ### Page 5 B.T. 109EP-79 Page 5 of 8 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 moistened in Methylethylketone. 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 109-0641-10-213 (or P/N 109- 0642-01-171), taking car e not to protrude stick out the metallic 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 a ssy P/N 109-0641-10-213 (or P/N 109-0642-01-171) install 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 origina l 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 109-0641-45-217 (or P/N 109-0642-01-169) using adhesive EC776. CAUTION If at step 4.3 stacked gaskets have been removed, bond them over the metallic spacers. 4.8 Inspect the main drive shaft tube in the semichannels area for damage (nicks and/or scratches). ### Page 6 B.T. 109EP-79 Page 6 of 8 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 109-0641-10-213 (or P/N 109-0642-01- 171), before to start with the removal operations in accordance with the instructions given in the A109E Maintenance Manual. 4.9 In case damages are reported, the main drive shaft shall be removed from the helicopter, in accordance with the instructions given in the A109E Maintenance Manual, for the damages depth measurement. CAUTION In case the damages depth is above to the value reported in th e A109E Maintenance Manual, 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 A109E Maintenance Manual. 4.11. If not already performed, reinstall the lower semichannel assy P/N 109-0641-10-213 (or P/N 109-0642-01-171) on the forward firewall assy P/N 109-0641-45-201 (or 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 lower 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 P22 and the right engine cowling P19, in accordance with the instructions given in the A109E Maintenance Manual. 6. Return the helicopter in ready to flight condition. 7. Record compliance of this Bollettino in the helicopter log book. ### Page 7 (OCR) B.T. 109EP-79 109-0641-45-173 OR: 109-0642-01-181 LH DOOR ASSY (REF) DETAIL A (SEE FIGURE 2) 109-0641-45-205 OR: 109-0642-01-182 RH DOOR ASSY (REF) VIEW LOOKING AFT OR: 109-0642-01-101 FWD FIREWALL ASSY (REF.) FIGURE 1 (Reference illustration) Page 7 of 8 ### Page 8 (OCR) B.T. 109EP-79 Ø2,5 mm DRILL ON INSTALLATION INSTALL: MS20427M3 RIVET OR: MS20426T3 RIVET OR: UPPER SEMICHANNEL OF THE A298A04TW02 RIVET (TYP. 2 PLACES) DOOR ASSY 109-0641-45 OR 109-0642-01 (REF.) MS27039-08-05 SCREW (REF) NAS1149C0332R WASHER (REF) (TYP. 2 PLACES) 109-0641-45-217 B OR: 109-0642-01-169 GASKET (REF.) BOND WITH ADHESIVE EC776 (TYP. 2 PLACES) 109-0642-01-195 METALLIC SPACER (REF.) (TYP. 2 PLACES) 109-0641-10-213 OR: 109-0642-01-171 LOWER SEMICHANNELL ASSY (REF.) MS21069L3K NUTPLATE (REF.) (TYP. 2 PLACES) DETAIL A 18.0 (REF.) DRILL ON INSTALLATION (TYP.) Ø 5.0 R → (REF.) 73.0 92.0 (REF) 109-0641-10-213 OR: 109-0642-01-171 LOWER SEMICHANNELL ASSY (REF.) VIEW FROM B FIGURE 2 (Reference illustration - Dimensions in mm) Page 8 of 8 ### Page 9 Note: Remarks: Informazioni: Information: Al fine di gestire le varianti alla configurazione base, in relazione all’emissione del Bollettino Tecnico, preghiamo di voler compilare il presen- te modulo in tutte le sue parti e spedirlo all’indirizzo sopra indicato. Si ringrazia 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 Via per Tornavento, 15 21019 Somma Lombardo (VA) - ITALY Tel.: +39 0331 711100 Fax: +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. ### Page 10 (No text on this page.) --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain, except the copies of manufacturers’ service documents, which belong to their rights holders.