# Leonardo Alert Service Bulletin 139-452: Revision B - Rights: © Leonardo S.p.A. Filed by the FAA in regulations.gov docket FAA-2020-0283, the docket of AD 2021-23-22. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Leonardo Alert Service Bulletin 139-452](https://openairdocs.org/service-documents/leonardo/sb-139-452.md) - Title as filed: Leonardo Helicopters ASB No. 139-452 Rev B - Pages: 12 - PDF: https://openairdocs.org/files/sha256/f9/32/f932c5c19ce7fcf3a4ecd80e495e35ddd155324120cb4e3cfec804a1160f8006 - Page: https://openairdocs.org/service-documents/leonardo/sb-139-452/file/f932c5c19ce7 ## Text Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 N° 139-452 DATE: June 27, 2016 REV. : B - April 10, 2018 Page 1 of 11 TITLE ATA 62 - MAIN ROTOR DAMPER INSPECTION AND REPLACEMENT REVISION LOG Present revision B is issued to remove from the effectivity of part II of this Service Bulletin MR damper P/N 3G6220V01353, introduced with revision A, because is no more subject to the inspections described in the previous issues. The maintenance program applicable to MR damper P/N 3G6220V01353 has been reported in AMPI Chapter 5 Issue 15. Moreover, it prescribes the replacement of the MR damper, once the body end has logged twelve hundred (1200) FH or more since new. The replacement of MR damper with P/N 3G6220V01353 is considered terminating action for the inspections prescribed in Service Bulletin 139-450. Revision bars in the outer margin identify changes. 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°139-452 ALERT DATE: June 27, 2016 Page 2 of 11 REVISION: B - April 10, 2018 1. PLANNING INFORMATION A. EFFECTIVITY PART I All AB139 / AW139 helicopters (except S/N 31004, S/N 31007 and S/N 41237) equipped with MR dampers P/N 3G6220V01351 or P/N 3G6220V01352 or P/N 3G6220V01353. PART II All MR dampers P/N 3G6220V01351 or P/N 3G6220V01352 installed on AB139 / AW139 helicopters (except S/N 31004, S/N 31007 and S/N 41237) having a body end P/N M006-01H002-041 or P/N M006-01H002-047. NOTE Implementation of part I is not required for helicopters that have already accomplished it complying with the previous issues of this Service Bulletin. B. COMPLIANCE NOTE Body end time since new or since overhaul can be computed based on removal/installation data recorded on MR damper logcard Section 2. PART I After the last flight of the day or within ten (10) FH after receipt of this Service Bulletin, whichever occurs later. PART II Within thirty (30) FH from the receipt of this Service Bulletin or when MR damper body end P/N M006-01H002-041 or P/N M006-01H002-047 reach twelve hundred (1200) FH since new, whichever occurs later. C. CONCURRENT REQUIREMENTS N.A. ### Page 3 S.B. N°139-452 ALERT DATE: June 27, 2016 REVISION: B - April 10, 2018 Page 3 of 11 D. REASON This Service Bulletin is issued in order to reduce the MR damper body end nut tightening torque and to prescribe the replacement of the MR damper P/N 3G6220V01351 and P/N 3G6220V01352 with P/N 3G6220V01353, once the body end has logged twelve hundred (1200) FH or more since new. E. DESCRIPTION Following the actions started with BT 139-450, this Service Bulletin prescribes, in part I, a new lower value of MR damper locking torque installation on MR hub side, in order to reduce stress on the body end. Part II provides the instruction to replace the MR dampers P/N 3G6220V01351 or P/N 3G6220V01352 with P/N 3G6220V01353, that are no more subject to the recurrent inspections described in Service Bulletin 139 -450 and whose maintenance tasks have been introduced in AMPI Chapter 5 starting from Issue 15. 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. 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 the following MMH are deemed necessary: Part I: three (3) MMH; Part II: one (1) MMH for each affected MR damper. MMH are based on hands-on time and can change with personnel and facilities available. ### Page 4 S.B. N°139-452 ALERT DATE: June 27, 2016 Page 4 of 11 REVISION: B - April 10, 2018 H. WEIGHT AND BALANCE N.A. I. REFERENCES 1) PUBLICATIONS DATA MODULE DESCRIPTION PART DM01 39-A-00-20-00-00A-120A-A Helicopter on ground for a safe maintenance I, II DM02 39-A-GG-02-00-00A-066A-A Platform, left (GG-01-00) I, II DM03 39-A-62-22-02-00A-520A-A Main rotor damper – Remove procedures II DM04 39-A-62-22-02-00A-720A-A Main rotor damper – Install procedures II DM05 39-A-62-22-07-00A-520A-A Anti-rotation block - Remove procedure II DM06 39-A-62-22-07-00A-720A-A Anti-rotation block - Install procedure II 2) ACRONYMS AMDI Aircraft Material Data Information AMP Aircraft Maintenance Publication AMPI Aircraft Maintenance Planning information AR As Required BT Bollettino Tecnico DM Data Module FH Flight Hours ITEP Illustrated Tools and Equipment Publication LHD Leonardo Helicopter Division LS Local Supply MMH Maintenance-Man-Hours MMIR Maintenance Malfunction Information Report MR Main Rotor 3) ANNEX Annex A MR damper eddy current inspection ### Page 5 S.B. N°139-452 ALERT DATE: June 27, 2016 REVISION: B - April 10, 2018 Page 5 of 11 J. PUBLICATIONS AFFECTED N.A. K. SOFTWARE ACCOMPLISHMENT SUMMARY N.A. ### Page 6 S.B. N°139-452 ALERT DATE: June 27, 2016 Page 6 of 11 REVISION: B - April 10, 2018 2. MATERIAL INFORMATION A. REQUIRED MATERIALS 1) PARTS NOTE MR damper P/N 3G6220V01353 is fully interchangeable and mixable on the same MR Hub with a damper with different P/N. If a MR damper P/N 3G6220V01353 is furnished to replace a damper with different P/N, also a new antirotation block P/N 3G6220A05353 must be supplied to replace the existing one. The new anti-rotation block P/N 3G6220A05353 can be used also with damper with different P/N. PART I # P/N ALTERNATIVE P/N DESCRIPTION Q.TY LVL NOTE LOG P/N 1 MS24665-374 Cotter pin 5 LS / PART II # P/N ALTERNATIVE P/N DESCRIPTION Q.TY LVL NOTE LOG P/N 2 3G6220V01353 MR damper AR / 3 3G6220A05353 Antirotation block AR / 2) CONSUMABLES The following consumable materials, or equivalent, are necessary to accomplish this Service Bulletin: # Spec./LHD code number DESCRIPTION Q.TY NOTE PART 4 Commercial Clean, lint-free, dry cloth (C011) or absorbent towelling AR LS I Refer also to AMDI for the consumable materials required to comply with the AMP DM referenced in the compliance instructions. 3) LOGISTIC MATRIX N.A. ### Page 7 S.B. N°139-452 ALERT DATE: June 27, 2016 REVISION: B - April 10, 2018 Page 7 of 11 B. SPECIAL TOOLS The following special tools, or equivalent, are necessary to accomplish this Service Bulletin: # P/N DESCRIPTION Q.TY NOTE PART 5 RMGE-DS-06-2010-LH or approved alternative Platform left (GG-01-00) AR LS I, II Refer also to ITEP for the special tools required to comply with the AMP DM referenced in the compliance instructions. C. INDUSTRY SUPPORT INFORMATION WARRANTY: Owners/Operators who comply with the instructions of this Service Bulletin no later than the applicable date in the “Compliance” section will be eligible to receive Main Rotor Damper on a free of charge basis, except for Consumable Materials & Special Tools. Please Issue relevant MMIR form to your Warranty Administration Dpt. ### Page 8 S.B. N°139-452 ALERT DATE: June 27, 2016 Page 8 of 11 REVISION: B - April 10, 2018 3. ACCOMPLISHMENT INSTRUCTIONS PART I 1. In accordance with AMP DM 39-A-00-20-00-00A-120A-A, prepare the helicopter on ground for a safe maintenance. Disconnect the battery, all electrical power sources and/or the external power supply. 2. Put the platform (GG- 01-00), or an approved alternative, adjacent to the left side of the fuselage. WARNINGS  THE MATERIALS THAT FOLLOW ARE DANGEROUS. BEFORE YOU DO THIS PROCEDURE, MAKE SURE THAT YOU KNOW ALL THE SAFETY PRECAUTIONS AND FIRST AID INSTRUCTIONS FOR THESE MATERIALS: - CORROSION INHIBITOR (C002); - CLEANING SOLVENT (C010).  THIS INSTALLATION INCLUDES VITAL POINTS (VP). DURING THE PROCEDURE, YOU MUST OBEY THE LOCAL REGULATIONS APPLICABLE TO THE VITAL POINTS. 3. Get access to the cockpit. Set the rotor brake lever to OFF. 4. With reference to figure 1, turn the MR head to move the applicable MR damper above the platform and get access to the work area. 5. Set the rotor brake lever to ON. 6. With reference to figure 1 section G-G, remove the nut from the bolt that fix the MR damper on the MR hub as follows: 6.1 Remove the existing corrosion inhibitor from the cotter pin and the nut, using a lint-free cloth (C011) and the cleaning solvent (C010). 6.2 Remove the cotter pin from the nut and the bolt. Discard the cotter pin. 6.3 Remove the nut from the bolt. Do not remove the bolt from the hub. 6.4 Clean bolt thread using a lint-free cloth (C011) and the cleaning solvent (C010). 7. Install the nut removed at step 6.3. Torque the nut to 74.6 thru 88 Nm (55 thru 64.9 lbf ft). 8. Secure the nut with a new cotter pin P/N MS24665-374. 9. Apply the corrosion inhibitor (C002) to the cotter pin, the nut and the washer. 10. Repeat steps 3 thru 9 until you have changed nut torque on all the MR dampers. 11. Remove the platform (GG- 01-00) from the left side of the fuselage. ### Page 9 S.B. N°139-452 ALERT DATE: June 27, 2016 REVISION: B - April 10, 2018 Page 9 of 11 12. Return the helicopter to flight configuration. 13. Record for compliance with part I of this Service Bulletin on the helicopter logbook. 14. Send the attached compliance form to the following mail box: cse.aw139.aw@leonardocompany.com As an alternative, gain access to My Communications section on Leonardo WebPortal and compile the “Service Bulletin Application Communication”. ### Page 10 S.B. N°139-452 ALERT DATE: June 27, 2016 Page 10 of 11 REVISION: B - April 10, 2018 PART II 1. In accordance with AMP DM 39-A-00-20-00-00A-120A-A, prepare the helicopter on ground for a safe maintenance. Disconnect the battery, all electrical power sources and/or the external power supply. 2. Put the platform (GG- 01-00), or an approved alternative, adjacent to the left side of the fuselage. 3. In accordance with AMP DM n° 39-A-62-22-02-00A-520A-A remove the affected MR damper. NOTE MR damper P/N 3G6220V01353 is fully interchangeable and mixable on the same MR Hub with a damper with different P/N. When MR damper P/N 3G6220V01353 is furnished to replace a damper with different P/N, also a new antirotation block P/N 3G6220A05353 must be supplied to replace the existing one. The new anti- rotation block P/N 3G6220A05353 can be used also with damper with different P/N. 4. In accordance with AMP DM n° 39-A-62-22-07-00A-520A-A and DM n° 39-A-62-22-07- 00A-720A-A, replace the existing antirotation block with a new one P/N 3G6220A05353 , if not already installed. 5. In accordance with AMP DM n° 39-A-62-22-02-00A-720A-A i nstall MR damper P/N 3G6220V01353. 6. Repeat steps 3 and 5 for all MR dampers with body end having logged twelve hundred (1200) FH or more since new. 7. Remove the platform (GG- 01-00) from the left side of the fuselage. 8. Return the helicopter to flight configuration. 9. Record for compliance with part II of this Service Bulletin on the helicopter logbook. 10. Send the attached compliance form to the following mail box: cse.aw139.aw@leonardocompany.com As an alternative, gain access to My Communications section on Leonardo WebPortal and compile the “Service Bulletin Application Communication”. ### Page 11 Figure 1 S.B. N°139-452 ALERT DATE: June 27, 2016 REVISION: B - April 10, 2018 Page 11 of 11 ### Page 12 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. Source documents are U.S. government works in the public domain, except the copies of manufacturers’ service documents, which belong to their rights holders.