# Agusta Bollettino Tecnico 412-128: No revision named - Rights: © Leonardo S.p.A. Filed by the FAA in regulations.gov docket FAA-2026-0014, the docket of AD 2026-02-05. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Agusta Bollettino Tecnico 412-128](https://openairdocs.org/service-documents/leonardo/sb-412-128.md) - Title as filed: Leonardo ASB 412-128 Rev A - Pages: 8 - PDF: https://openairdocs.org/files/sha256/67/c4/67c448da660b89b3f7e90cc5e9e2230835463fad534cb105b15cc5c8ef6af62a - Page: https://openairdocs.org/service-documents/leonardo/sb-412-128/file/67c448da660b ## 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 Pa ge 1 of 7 N° 412-128 DA TE: August 17, 2009 REV. : A - May 24, 2024 TITLE ATA 53 – LEFT FUSELAGE UPPER CAP ANGLE P/N 212-030-191-1, INSPECTION OF REVISION LOG This Service Bulletin cancels and supersedes Bollettino Tecnico nr. 412-128 issued on 1 7 August 2009. Revision A is issued to:  Update to the latest standard form  Update paragraph 1.B, 1.D, 1.E, 1.F, 1.G, 1.I.I.1, 1.I.I.2, 1.K, 3 and Figure 1. An appropriate entry should be made in the aircraft log book upon accomplishment. If ownership of aircraft has changed, please, forward to new owner. Leonardo S.p.A. Via Giovanni Agusta, 520 21017 Cascina Costa di Samarate (VA) Italy Tel.: +39 0331 229111 - Fax: +39 0331 229605/222595 ALERT SERVICE BULLETIN ### Page 2 S.B. N°412-128 ALERT DATE: August 17, 2009 Page 2 of 7 REVISION: A - May 24, 2024 1. PLANNING INFORMATION A. EFFECTIVITY All AB412/412EP helicopters. B. COMPLIANCE Perform the inspection within 25 flight hours since last 100 flight hour inspection of the cap angle, or 5 flight hours after receipt of this Service Bulletin, whichever occurs later, and recursively every 25 flight hours thereafter. C. CONCURRENT REQUIREMENTS N.A. D. REASON Provide the instructions to perform the inspection of cap angle P/N 212-030-191-1 in the area near the left upper tailboom fitting (ref. Figure 2). E. DESCRIPTION A helicopter AB412EP has reported a case of crack to the cap angle P/N 212-030-191- 1 in the area near the left upper tailboom fitting. This Service Bulletin is issued to prescribe the visual inspection, with the aid of a magnifying glass, of the upper left cap angle P/N 212-030-191-1, in the area shown in Figure 2. Since the release of the basic revision of this Service Bulletin, LHD has not been made aware of other instances of cracked cap angles, P/N 212-030-191-1, across the AB412/412EP fleet. However, Bell Helicopter Textron has recently shared with LHD the results of investigations into cracked cap angles on Model 412/412EP helicopters. In light of this new information, with revision A of this Service Bulletin, LHD reduces to 25 flight hours the repetitive inspection interval that was set at 100 flight hours by the basic revision of this Service Bulletin. F. APPROVAL The technical content of this Service Bulletin is approved under the authority of DOA nr. EASA.21.J.005. For helicopters registered under other Aviation Authorities, before applying the Service Bulletin, applicable Aviation Authority approval must be checked within Leonardo Helicopters customer portal. ### Page 3 S.B. N°412-128 ALERT DATE: August 17, 2009 REVISION: A - May 24, 2024 Page 3 of 7 EASA states mandatory compliance with inspections, modifications or technical directives and related time of compliance by means of relevant Airworthiness Directives. If an aircraft listed in the effectivity embodies a modification or repair not LHD certified and affecting the content of this Service Bulletin, it is responsibility of the Owner/Operator to obtain a formal approval by Aviation Authority having jurisdiction on the aircraft, for any adaptation necessary before incorporation of the present Service Bulletin. G. MANPOWER To comply with this Service Bulletin half an hour (0.5) MMH are deemed necessary. MMH are based on hands-on time and can change with personnel and facilities available. MMH are not comprehensive of the overall hours necessary to get access to work areas and to remove all the equipment that interferes with the application of the prescribed instructions. H. WEIGHT AND BALANCE N.A. I. REFERENCES I.1 PUBLICATIONS AB412-MM Maintenance Manual I.2 ACRONYMS & ABBREVIATIONS DOA Design Organization Approval EASA European Aviation Safety Agency LH Leonardo Helicopters MM Maintenance Manual MMH Maintenance Man Hours N.A. Not Applicable P/N Part Number S.B. Service Bulletin I.3 ANNEX N.A. ### Page 4 S.B. N°412-128 ALERT DATE: August 17, 2009 Page 4 of 7 REVISION: A - May 24, 2024 J. PUBLICATIONS AFFECTED AB412-MPM Maintenance Planning Manual K. SOFTWARE ACCOMPLISHMENT SUMMARY N.A. 2. MATERIAL INFORMATION A. REQUIRED MATERIALS A.1 PARTS N.A. A.2 CONSUMABLES N.A. B. SPECIAL TOOLS N.A. C. INDUSTRY SUPPORT INFORMATION N.A. ### Page 5 S.B. N°412-128 ALERT DATE: August 17, 2009 REVISION: A - May 24, 2024 Page 5 of 7 3. ACCOMPLISHMENT INSTRUCTIONS 1. In accordance with AB412-MM Maintenance Manual, prepare the helicopter on ground for a safe maintenance. Disconnect the battery, all electrical power sources and/or the external power supply. 2. With reference to Figure 1, gain access to the upper left cap angle in the tail rotor servo compartment through the R/H aft fuselage door. 3. Clean the cap angle P/N 212-030-191-1 in the area noted on Figure 2 with denatured alcohol or equivalent. 4. Inspect the area noted on Figure 2 of cap angle P/N 212-030-191-1 with a 5X magnifying glass and a bright light. NOTE The presence of black area around the Hi-lock heads (“smoking” of fitting attachment) and crazing of sealant bead around the fitting might indicate the presence of an initial crack of the cap with looseness of the part. 5. If no cracks are revealed, proceed in accordance with step 7 of this Service Bulletin. 6. If a crack is found, before further flight, contact Leonardo Helicopters for further instruction at the following mailbox: absereng.aw@leonardo.com 7. Return the helicopter to flight configuration and record for compliance with this Service Bulletin on the helicopter logbook. 8. Send the attached compliance form to the following mailbox: absereng.aw@leonardo.com As an alternative, gain access to My Communications section on Leonardo WebPortal and compile the “Service Bulletin Application Communication”.  Non cancellare mai questo segnalibro Non cancellare mai interruzione sezione  ### Page 6 (OCR) K LEONARDO HELICOPTERS CAP ANGLE P/N 212-030-191-1 L/H UPPER TAILBOOM ATTACH FITTING P/N 212-030-159-1 Figure 1 - Internal fuselage - Left side S.B. N°412-128 ALERT DATE: August 17, 2009 Page 6 of 7 REVISION: A - May 24, 2024 ### Page 7 Figure 2 - Internal fuselage - Left side detail S.B. N°412-128 ALERT DATE: August 17, 2009 REVISION: A - May 24, 2024 Page 7 of 7 INSPECTION AREA CAP ANGLE P/N 212-030-191-1 L/H UPPER TAILBOOM ATTACH FITTING P/N 212-030-159-1 FUSELAGE BULKHEAD P/N 212-030-156 REF. TAILBOOM REF. ### Page 8 Remarks: Information: SERVICE BULLETIN COMPLIANCE FORM Date: Number: Revision: Please send to the following address: Telephone: Fax: B.T. Compliance Date: Customer Name and Address: Helicopter Model S/N Total Number Total Hours T.S.O. LEONARDO S.p.A. CUSTOMER SUPPORT & SERVICES - ITALY PRODUCT SUPPORT ENGINEERING & LICENSES DEPT. Via Giovanni Agusta, 520 21017 Cascina Costa di Samarate (VA) - ITALY Tel.: +39 0331 225036 Fax: +39 0331 225988 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 or you can communicate the application also via Technical Bulletin Application Communication Section placed in Leonardo AW Customer Portal - MyCommunications Area. We thank you beforehand for the information given. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. 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