# Leonardo Alert Service Bulletin 189-237: Revision C - Rights: © Leonardo S.p.A. Filed by the FAA in regulations.gov docket FAA-2021-0612, the docket of AD 2021-20-17. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Leonardo Alert Service Bulletin 189-237](https://openairdocs.org/service-documents/leonardo/sb-189-237.md) - Title as filed: Leonardo Helicopters Emergency ASB No. 189-237 Rev C - Pages: 38 - PDF: https://openairdocs.org/files/sha256/fa/83/fa83f442d1bf1902a16f90568090fd293f17cdcb1a376caf140b988b9769a35d - Page: https://openairdocs.org/service-documents/leonardo/sb-189-237/file/fa83f442d1bf ## 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 N° 189-237 DA TE: May 29, 2019 REV. : C - April 6, 2020 Pa ge 1 of 37 TITLE ATA 64 - TAIL ROTOR FLIGHT CONTROL IMPROVED PERIODICAL INSPECTION REVISION LOG Revision C of this Service Bulletin cancels and supersedes all the previous Revisions. R evision A is issued in order to introduce the following changes: • Update the “Compliance” section clarifying the note relevant to accomplishment of Part VI. • Provide instruction to remove the castellated nut in place of loosen it while performing the replacement of the TR duplex bearing. • Add closure action in case of findings after accomplishment with Part VI step 3. • Add cleaning instruction of the TR duplex bearing area in Part V before installation of the spider plug. • Add details to cleaning procedure of spacer control rod surface with aliphatic naphtha. • Add use of a borescope as alternative mean to perform inspection of Part I, in such case the removal of the access panels 495A and 496A is not required. • In case of no-findings after the inspections, it is not required anymore to send feedback to LHD. • Add HUMS data download in case TRA HUMS accelerometer has been already installed to helicopter. • Update the reference to Annex A - UTC Microtecnica Service Bulletin 67-0006 Issue 1. Leonardo S.p.A. Via Giovanni Agusta, 520 21017 Cascina Costa di Samarate (VA) Italy Tel.: +39 0331 229111 - Fax: +39 0331 229605/222595 An appropriate entry should be made in the aircraft log book upon accomplishment. If ownership of aircraft has changed, please, forward to new owner. EMERGENCY ALERT SERVICE BULLETIN ### Page 2 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 Page 2 of 37 REVISION: C - April 6, 2020 Re vision B is issued in order to introduce the following changes: • Change effectivity for Part I from “All AW 189 helicopters” to “All AW 189 helicopters equipped with TRA P/N 6F6730V00331”; • Remove Annex A and all the references to the subject document, as all the relevant information is now enclosed in applicable AMP Data Modules. Revision C is issued in order to introduce the following changes: • Insert a new note in Part II, IV, V and VI that completes control rod nut installation instruction when reinstalling spider and slider assembly. Revision bars in the margins identify changes. ### Page 3 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 REVISION: C - April 6, 2020 Page 3 of 37 1. PLANNING INFORMATION A. EFFECTIVITY Part I: All AW189 helicopters equipped with TRA P/N 6F6730V00331. P art II: All AW189 helicopters. Part III: All AW189 helicopters. Part IV: All AW189 helicopters. Part V: All AW189 helicopters. Part VI: All AW189 helicopters. B. COMPLIANCE Part I: Within 10 FH from last application of Part I of SB 189-224 or from the issue of this Service Bulletin, whichever occurs first. Then repeat the inspection every 10 FH. NOTE Every time it is required to perform Part II, accomplishment of Part I, Part IV and Part V on the same maintenance downtime, must be performed as a prerequisite. If Part III is required in the same maintenance downtime, it shall be performed last. Part II: Within 50 FH from last application of Part II of SB 189-224 or from the issue of this Service Bulletin, whichever occurs first. Then repeat the inspection every 50 FH. Part III: Within 20 FH from last application of Part III of SB 189-224 or from the issue of this Service Bulletin, whichever occurs first. Then repeat the installation every 20 FH. Part IV: Within 10 FH from last application of Part IV of SB 189-224 or from the issue of this Service Bulletin, whichever occurs first. Then repeat the inspection every 10 FH. NOTE Perform as a prerequisite Part I and Part IV. If Part III is required in the same maintenance downtime, it shall be performed lastly. ### Page 4 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 Page 4 of 37 REVISION: C - April 6, 2020 Pa rt V: Within 10 FH from last application of Part I of SB 189-224 or from the issue of this Service Bulletin, whichever occurs first. Then repeat the inspection every 10 FH. NOTE • After the first accomplishment of Part VI repeat Part VI phased with Part II, not exceeding 200FH from the first application of the Part VI. Then repeat every 200FH. • Perform in sequence Part I, Part IV, Part V as a prerequisite. • If Part II is required in the same maintenance downtime, it shall be performed after Part V and before Part VI. • If Part III is required in the same maintenance downtime, it shall be performed after Part VI. Part VI: Within 10 FH from last application of Part I of SB 189-224 or from the issue of this Service Bulletin, whichever occurs first. Then repeat the inspection every 200 FH. C. CONCURRENT REQUIREMENTS This SB supersedes and replaces the SB 189-224. D. REASON This Service Bulletin is issued in order to require the periodical inspection of the sl ippage marking of the back-end castellated nut of the TR servo-actuator and the periodical detailed inspection of the TR duplex bearing. E. DESCRIPTION Following additional tests and the completion of the initial phase of the in service m onitoring carried out on the AW169 and AW189 fleet, it has been confirmed that the introduction of a temperature monitoring represents an effective independent measure to confirm the health of the TR bearing. In addition a refinement of the current inspection schedule is required with this SB along with the introduction of an additional instruction for duplex bearing roughness check. This Service Bulletin provides the instructions for the above together with the transition to the new inspection regime. ### Page 5 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 REVISION: C - April 6, 2020 Page 5 of 37 In details Part I of this Service Bulletin provides the periodical detailed inspection of the slippage marking of the castellated nut installed on the back end of the TRA. Part II partly retains the requirement of the Part II of the SB 189-224 defining the required detailed inspection requirement of TR duplex bearing. Part III provides the instructions to install a dedicated thermal strip in the area of the TR duplex bearing. Part IV provides the instructions to recursively check the thermal strip. Part V requires the verification of metallic particle presence in the grease that could be found on the visible part of the duplex bearing. This check was already present in the Part II of the SB 189-224 and it is now confirmed with a tighter compliance. Part VI prescribe an additional roughness check of the duplex bearing to be performed after removal of the spider assembly. Incorrect installation of the TR servo-actuator back-end nut or seizure of the TR duplex bearing may lead to loss of Tail Rotor control which, depending on the flight condition, could lead to loss of control of the aircraft. Feedback on the compliance to this Service Bulletin is required. Revision A of this Service Bulletin allows the simplification of Part I inspection and reduce the amount of feedback required after “no-findings” inspections. F. APPROVAL The technical content of this Service Bulletin is approved under the authority of DOA n r. 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. E.A.S.A. 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: P art I: approximately one (0.5); Part II: approximately three (3); ### Page 6 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 Page 6 of 37 REVISION: C - April 6, 2020 Pa rt III: approximately half (0.5); Part IV: approximately one (1). Part V: approximately one (0.5); Part VI: approximately three (3); MMH are based on hands-on time and can change with personnel and facilities available. H. WEIGHT AND BALANCE N.A. I. REFERENCES 1) PUBLICATIONS DATA MODULE DESCRIPTION PART DM01 89-A-00-20-00-00A-120A-A Helicopter on ground for a safe maintenance. I, II; III, IV, V, VI DM02 89-A-06-41-00-00A-010A-A Access door provision I, II DM03 89-A-64-31-01-00A-520A-A Pitch link - Remove procedure II DM04 89-A-64-31-01-00A-720A-A Pitch link - Install procedure II, IV, V, VI DM05 89-A-64-31-03-00A-520A-A Spider plug - Remove procedure II, III, IV,V DM06 89-A-64-31-03-00A-720A-A Spider plug - Install procedure II, III, IV, V DM07 89-A-64-31-02-00A-520A-A Scissors group – Remove procedure II DM08 89-A-64-31-04-00A-520A-A Spider and slider assembly - Remove procedure II, VI DM09 89-A-64-31-04-00A-720A-A Spider and slider assembly - Install procedure II, VI DM10 89-A-64-31-05-00A-520A-B Duplex bearing - Remove procedure II, IV, V, VI DM11 89-A-64-31-05-00A-720A-B Duplex bearing - Install procedure II, IV, V, VI 2) ACRONYMS SB Service Bulletin D M Data Module DOA Design Organization Approval EASA European Aviation Safety Agency LHD Leonardo Spa Helicopters ### Page 7 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 REVISION: C - April 6, 2020 Page 7 of 37 MMH Maintenance Man Hours SB Service Bulletin FH Flight Hours TR Tail Rotor TRA Tail Rotor Actuator 3) ANNEX N.A. J. PUBLICATIONS AFFECTED N.A. K. SOFTWARE ACCOMPLISHMENT SUMMARY N.A. ### Page 8 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 Page 8 of 37 REVISION: C - April 6, 2020 2. MATERIAL INFORMATION A. REQUIRED MATERIALS 1) PARTS Refer to AW189 IPD for the spares materials required to comply with the AMP DMs r eferenced in the accomplishment instructions. 2) CONSUMABLES T he following consumable materials, or equivalent, are necessary to accomplish this Service Bulletin: # Spec./LHD code number DESCRIPTION Q.TY NOTE PART 1 Thermax 8 Level strip indicator code No.26805 Thermal strip AR (1)(2)(3) III,IV 2 TT-N-95-B / Code No. 531055030 Aliphatic Naphtha (C059) AR (1) III,IV Refer to AW189 AMDI for the consumables required to comply with the AMP DMs referenced in the accomplishment instructions. 3) LOGISTIC MATRIX N .A. NOTE (1) Item to be furnished as local supply. (2) Thermal strip Thermax 5 Level clock style indicator code No.26004 may be used as a valid alternative. (3) The use of further alternative strip is allowed provided that it complies with the following requirements: • Irreversible temperature indication. • Self-Adhesive. • Temperature Range shall be included within 100°C – 160°C provided that it shows a discrete level at 121±2°C. • Overall measurement accuracy: ±2°C. • The maximum allowed length to prevent overlap is 80 mm. In case any clarification is needed, contact the Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com). ### Page 9 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 REVISION: C - April 6, 2020 Page 9 of 37 B. SPECIAL TOOLS Refer to ITEP for the special tools required to comply with the AMP DMs referenced in t he accomplishment instructions. C. INDUSTRY SUPPORT INFORMATION Owners/Operators who comply with the instructions of this Service Bulletin no later t han the applicable date in the “Compliance” section will be eligible to receive REQUIRED MATERIALS on free of charge basis, except for Consumable Materials and Special Tools. NOTE: Customers who fail to comply with the instructions in this Service Bulletin before the compliance date are not eligible for the aforementioned special policy. Please Issue relevant MMIR form to your Warranty Administration Dpt. NOTE: WRM will include RETURN MATERIAL AUTHORIZATION (RMA) number; the unit disembarked from the aircraft has to be returned to LHD within thirty (30) calendar days after the shipment of the replacement part. In case of missing return within thirty (30) calendar days, Customer will be invoiced for the price of the replacement part. ### Page 10 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 Page 10 of 37 REVISION: C - April 6, 2020 3. ACCOMPLISHMENT INSTRUCTIONS GENERAL NOTES a) Place an identification tag on all components that are re-usable, including the attaching hardware that has been removed to gain access to the modification area and adequately protect them until their later re-use. PART I 1. In accordance with AMP DM 89-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. NOTE Removal of access panels 496A and 495A can be avoided if visual access to the inspection area is available by other means. A suitable boroscope can be inserted in the grid of access panel 496A as shown on Figure 3. 2. In accordance with AMP DM 89-A-06-41-00-00A-010A-A , remove the access panels 496A and 495A. 3. Take a picture of the back-end area of the TRA clearly showing the slippage mark, and keep a record in a local archive to be made available if required. 4. With reference to Figure 3, check the slippage mark on the castellated nut for absence of evidence of rotation between the parts. Record the result on Table I (refer to Figure 7). 5. If any evidence of rotation is found, contact the Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com), wait for further instructions before to perform the following checks: 5.1 Perform Part II of this SB; 5.2 Perform Part V of this SB; 5.3 Send the picture taken at step 3 to Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com). 5.4 If the helicopter is already compliant with the SB 189-227, perform HUMS data download from AMMC to DTD. Upload the HUMS data to Heliwise. ### Page 11 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 REVISION: C - April 6, 2020 Page 11 of 37 6. If no evidence of rotation is found in step 4, return the helicopter to a ready to flight condition and record for compliance with Part I of this Service Bulletin on the helicopter logbook. 7. Send the attached compliance form and the compiled Table I to the following mail box: pse_aw189.mbx.aw@leonardocompany.com As an alternative, gain access to My Communications section on Leonardo WebPortal and compile the “Service Bulletin Application Communication”. ### Page 12 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 Page 12 of 37 REVISION: C - April 6, 2020 PA RT II 1. In accordance with AMP DM 89-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. In accordance with AMP DM 89-A-64-31-03-00A-520A-A, remove the spider plug. 3. In accordance with AMP DM 89-A-64-31-01-00A-520A-A, remove all the pitch links from the TR. 4. In accordance with applicable steps of AMP DM 89-A-64-31-02-00A-520A-A, disconnect the upper half scissors from the spider. 5. Remove and discard the strap that attach the boot to the spider and slider assembly. Disconnect and lower the boot from the spider. 6. Perform the inspection of the TR duplex bearing in accordance with the following procedure: 6.1 Inspect the visible part of the TR duplex bearing (including the seals) for absence of wear, damages and security of attachment. Record the results on Table II (refer to Figure 8). 6.2 Check for absence of axial play when trying to move the spider along the control rod axis. Record the result on Table II (refer to Figure 8). NOTE With reference to Figure 1 and Figure 2 Details B and C, apply a 35 ± 2.5 N upward force on the squared rod end by means of a dynamometer while performing the instructions reported in steps from 6.3 to 6.7. It is allowed to apply the force either pushing or pulling the rod end with the dynamometer. 6.3 Perform at least three (3) complete and continuo u s revolutions of the spider both in clockwise and in counterclockwise directions and verify that the spider has a free and easy rotation. Record the result on Table II (refer to Figure 8). 6.4 Put one arm of the spider along the vertical position; locate a dynamometer gauge on the spider arm hole (pitch link upper bolt location). Hold the gauge perpendicular to the spider arm surface. Gently push rightward the device until a slight rotation of the spider occurs (see Figure 2 for further details and dynamometer positioning). Record the force measured on Table II (refer to Figure 8). 6.5 Repeat step 6.4 for the opposite spider rotation on the same arm, pushing leftward the dynamometer gauge from the vertical position of the spider arm. ### Page 13 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 REVISION: C - April 6, 2020 Page 13 of 37 Record the force measured on Table II (refer to Figure 8). 6.6 Repeat steps 6.4 and 6.5 for all the other three spider arms. 6.7 The force detected by dynamometer on steps 6.4 thru 6.6 shall be measured within 2 N and 10 N. 7. If none of the checks performed in step 6 fails proceed as follows, otherwise skip to step 8. NOTE Removal of access panel 496A can be avoided if visual access to the inspection area is available by other means. A suitable boroscope can be inserted in the grid of access panel 496A as shown on Figure 3. 7.1 In accordance with AMP DM 89-A-06-41-00-00A-010A - A, remove the access panels 496A and 495A. 7.2 With reference to Figure 3, check the slippage mark on the castellated nut for absence of evidence of rotation between the parts by means of the borescope. If any evidence of rotation is found, immediately contact the PSE (pse_aw189.mbx.aw@leonardocompany.com) and wait for further instructions. 7.3 If the helicopter is already compliant with the SB 189-227, perform HUMS data download from AMMC to DTD. Upload the HUMS data to Heliwise. 7.4 Skip to step 12. 8. If one of the checks performed from step 6.1 to 6.2 fails skip to step 10, otherwise proceed with the following step 9. 9. If one of the checks performed from step 6.3 to step 6.7 fails proceed as follows: 9.1 Perform the cleaning procedure of the sliding control assy in accordance with the following procedure: 9.1.1 In accordance with AMP DM 89-A-06-41-00-00A-010A-A remove the access panels 496A and 495A. CAUTION Pay attention to prevent rod rotation, when screwing / un-screwing the castellated nut, holding the rod square end. 9.1.2 In accordance with AMP DM 89-A-64-31-04-00A-520 A-A, remove the spider and slider assembly. 9.1.3 Clean the external surface of the spider and slider assembly by means of soft lint-free cloth. ### Page 14 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 Page 14 of 37 REVISION: C - April 6, 2020 9. 1.4 Clean the accessible internal surface of the slider bushing by means of soft lint-free cloth. CAUTION Pay attention to prevent rod rotation, when screwing / un-screwing the castellated nut, holding the rod square end NOTE In case during the installation of control rod nut, after several attempts with different nuts, the minimum required breakaway torque (as required by AMP DM 89-A-64-31-04-00A-720A-A) is not reached, please contact the Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com) to receive dedicated instructions. 9.1.5 In accordance with AMP DM 89-A-64-31-04-00A-720 A-A, reinstall the spider and slider assembly. 9.1.6 With reference to Figure 3, restore the slippage marking on the castellated nut from the hinge bracket element to the rod. 9.2 Repeat steps from 6.2 to 6.7 to verify the absence of axial play of TR duplex bearing and to perform again the roughness and breakaway force checks of TR duplex bearing. 9.3 If any of the checks performed in step 9.2 fails proceed with the following step 10, otherwise skip to step 12. 10. Contact immediately the Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com) to receive further instruction before performing the replacement of the TR duplex bearing in accordance with the following procedure: 10.1 If the helicopter is already compliant with the SB 189-227, perform HUMS data download from AMMC to DTD. Upload the HUMS data to Heliwise. CAUTION Pay attention to prevent rod rotation, when screwing / un-screwing the castellated nut, holding the rod square end. ### Page 15 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 REVISION: C - April 6, 2020 Page 15 of 37 NOTE Before removal of the TR duplex bearing, take note of its installation orientation marking “OUT” on the outboard visible face. After removal mark “IN” on the inboard opposite face of the TR duplex bearing. Use an indelible pen. 10.2 In accordance with AMP DM 89-A-64-31-05-00A-520A -B, remove the TR duplex bearing. 10.3 Collect the grease leaked from the TR duplex bearing “IN” marked side in a container different from the one used before. 10.4 Take a picture of both faces of the removed TR duplex bearing and send them to PSE (pse_aw189.mbx.aw@leonardocompany.com) before returning the bearing. 10.5 Clean by means of a soft lint-free cloth the housing of the TR duplex bearing, the rod visible part and the internal side of the spider plug. CAUTION Pay attention to prevent rod rotation, when screwing / un-screwing the castellated nut, holding the rod square end. NOTE In case during the installation of control rod nut, after several attempts with different nuts, the minimum required breakaway torque (as required by AMP DM 89-A-64-31-04-00A-720A-A) is not reached, please contact the Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com) to receive dedicated instructions. 10.6 In accordance with AMP DM 89-A-64-31-05-00A-720A -B, install a new TR duplex bearing. 10.7 With reference to Figure 3, restore the slippage marking on the castellated nut from the hinge bracket element to the rod. 11. In case replacement of the TR duplex bearing is required, please return immediately (within 2 days) the removed TR duplex bearing and the collecting containers of the grease to Leonardo Helicopters. Contact the Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com) to receive the proper instructions to return the removed component. ### Page 16 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 Page 16 of 37 REVISION: C - April 6, 2020 12 . In accordance with AMP DM 89-A-64-31-01-00A-720A-A, while performing installation of TR pitch links, it is possible to re-protect TR pitch links and the scissors using the following procedure. 12.1 Clean the bolts by means of cleaning solvent. 12.2 Check the bolts looking for corrosion. Contact the Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com) in case of any findings. 12.3 Protect the parts using Tectyl Grade I or Thixoflex Black as a valid alternative. 13. In accordance with AMP DM 89-A-64-31-03-00A-720A-A, install the spider plug. NOTE In case of any findings, report within 2 days the inspection results along with the available records of the previous checks. 14. Send the attached compliance form and the compile d Table II to the following mail box: pse_aw189.mbx.aw@leonardocompany.com As an alternative, gain access to My Communications section on Leonardo WebPortal and compile the “Service Bulletin Application Communication”. 15. Return the helicopter to a ready to flight condition and record for compliance with Part II of this Service Bulletin on the helicopter logbook. ### Page 17 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 REVISION: C - April 6, 2020 Page 17 of 37 PART III 1. In accordance with AMP DM 89-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. In accordance with AMP DM 89-A-64-31-03-00A-520A-A, remove the spider plug. 3. With reference to Figure 4, perform the installation of thermal strip Thermax 8 level strip No.26805 or equivalent as follows: 3.1 Clean the spacer control rod P/N 4F6430A02551 surface with a soft lint-free cloth soaked with a small quantity of aliphatic naphtha. Then dry the surface with a clean cloth. 3.2 With reference to Figure 5, if the selected thermal strip exceeds the height of 16 mm it shall be cut taking care not to remove the Celsius scale and not to damage the sensitive elements of the strip. CAUTION When installing the thermal strip pay attention to: • avoid contact with bearing gaskets; • ensure a good adhesion with the spacer control rod P/N 4F6430A02551; • all temperature indicators of the thermal strip shall be visible. CAUTION If thermal strip trimming is required, confirm that the cut did not cause debonding of strip layers. 3.3 With reference to Figure 4, with the help of a no n metallic spatula, perform the installation of the thermal strip on the surface of the spacer control rod P/N 4F6430A02551. NOTE When performing the following step allow the sealant to cure for at least 2 hours before the next flight. 4. In accordance with AMP DM 89-A-64-31-03-00A-720A-A , install the spider plug. 5. Return the helicopter to a ready to flight condition and record for compliance with Part III of this Service Bulletin on the helicopter logbook. 6. Send the attached compliance form to the following mail box: pse_aw189.mbx.aw@leonardocompany.com As an alternative, gain access to My Communications section on Leonardo WebPortal and compile the “Service Bulletin Application Communication”. ### Page 18 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 Page 18 of 37 REVISION: C - April 6, 2020 PA RT IV 1. In accordance with AMP DM 89-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. In accordance with AMP DM 89-A-64-31-03-00A-520A-A, remove the spider plug. 3. With reference to Figure 4, check the thermal strip for good adhesion and readability and proceed as follows: 3.1 If the thermal strip is properly installed proceed with step 4; 3.2 If the strip is detached, partially detached or unreadable perform the spider and slider inspection in accordance with accomplishment instructions from step 3 to step 14 of Part II of this SB; 3.3 Replace the thermal strip in accordance with step 3 of Part III of this SB; 3.4 Skip to step 6. CAUTION In case the selected thermal strip does not provide a discrete value equal to 121°C, select the lowest value comprised within the range 121±2°C. 4. With reference to Figure 4, check the temperature reached by the thermal strip installed on spacer control rod P/N 4F6430A02551. Make sure that the temperature has not reached a value equal to or above 121°C. Record the check result on Table III (refer to Figure 9). 5. If temperature has exceeded a value equal to or above 121°C, contact immediately the Product Support Engineering ( pse_aw189.mbx.aw@leonardocompany.com) and perform the following procedure. Otherwise, skip to Step 6: 5.1 If the helicopter is already compliant with the SB 189-227, perform HUMS data download from AMMC to DTD. Upload the HUMS data to Heliwise. 5.2 Contact immediately the Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com) to receive further instruction before thermal strip and duplex bearing removal and replacement. 5.3 Perform from step 3 to step 14 of Part II of this SB. 5.4 Perform from step 3 to step 10 of Part V of this SB. 5.5 Remove the spacer control rod P/N 4F6430A02551, without removing the thermal strip. 5.6 Take a picture of the thermal strip, installed on the removed spacer control rod P/N 4F6430A02551 and send it to Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com). ### Page 19 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 REVISION: C - April 6, 2020 Page 19 of 37 CAUTION Pay attention to prevent rod rotation, when screwing / un-screwing the castellated nut, holding the rod square end. NOTE Before removal of the TR duplex bearing, take note of its installation orientation marking “OUT” on the outboard visible face. After removal mark “IN” on the inboard opposite face of the TR duplex bearing. Use an indelible pen. 5.7 In accordance with AMP DM 89-A-64-31-05-00A-520A - B, remove the TR duplex bearing. 5.8 Collect the grease leaked from the TR duplex bearing “IN” marked side in a container different from the one used before. 5.9 Take a picture of both faces of the removed TR duplex bearing and send them to PSE (pse_aw189.mbx.aw@leonardocompany.com) before returning the bearing. 5.10 Clean by means of a soft lint-free cloth the housing of the TR duplex bearing, the rod visible part and the internal side of the spider plug. CAUTION Pay attention to prevent rod rotation, when screwing / un-screwing the castellated nut, holding the rod square end. NOTE In case during the installation of control rod nut, after several attempts with different nuts, the minimum required breakaway torque (as required by AMP DM 89-A-64-31-04-00A-720A-A) is not reached, please contact the Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com) to receive dedicated instructions. 5.11 In accordance with AMP DM 89-A-64-31-05-00A-720A -B, install a new TR duplex bearing. 5.12 With reference to Figure 3, restore the slippage marking on the castellated nut from the hinge bracket element to the rod. 5.13 In case replacement of the TR duplex bearing is required, please return ### Page 20 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 Page 20 of 37 REVISION: C - April 6, 2020 im mediately (within 2 days) the removed TR duplex bearing, the collecting containers of the grease and the thermal strip to Leonardo Helicopters. Contact the Product Support Engineering ( pse_aw189.mbx.aw@leonardocompany.com) to receive the proper instructions to return the removed component. 5.14 In accordance with AMP DM 89-A-64-31-01-00A-720A-A, while performing installation of TR pitch links, it is possible to re-protect TR pitch links and the scissors using the following procedure 5.14.1 Clean the bolts by means of cleaning solvent. 5.14.2 Check the bolts looking for corrosion. Contact the Product Support Engineering ( pse_aw189.mbx.aw@leonardocompany.com) in case of any findings. 5.14.3 Protect the parts using Tectyl Grade I or Thixoflex Black as a valid alternative. 5.15 Go to step 6. 6. In accordance with AMP DM 89-A-64-31-03-00A-720A-A, install the spider plug. 7. Return the helicopter to a ready to flight condition and record for compliance with Part IV of this Service Bulletin on the helicopter logbook. NOTE In case of any findings, report within 2 days the inspection results along with the available records of the previous checks. 8. Send the attached compliance form and the compile d Table III to the following mail box: pse_aw189.mbx.aw@leonardocompany.com As an alternative, gain access to My Communications section on Leonardo WebPortal and compile the “Service Bulletin Application Communication”. ### Page 21 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 REVISION: C - April 6, 2020 Page 21 of 37 PART V 1. In accordance with AMP DM 89-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. In accordance with AMP DM 89-A-64-31-03-00A-520A-A, remove the spider plug. 3. Perform a detailed inspection of TR duplex bearing in accordance with the following procedure: 3.1 Check the visible part of the TR duplex bearing for particles absence. CAUTION Pay attention not to damage the thermal strip during the grease sampling from the bearing housing. 3.2 Check the visible part of the TR duplex bearing a nd/or the spider plug for grease leakage and confirm absence of any particles by finger touch. 3.3 Put a small quantity of grease using a small spatula in a transparent container and add a solvent (aliphatic naphtha). Then by using a magnet on the bottom out side of the container check for presence of metallic particles. 3.4 Record the result on Table IV (refer to Figure 10) and collect the grease leaked from the visible surface in a proper container. 4. If magnetic metallic and/or any other particles are found during accomplishment of step 3 proceed with the following step 5, otherwise skip to step 9. 5. Perform from step 3 to step 14 of Part II of this SB. 6. Contact immediately the Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com) to receive further instruction before performing the replacement of the TR duplex bearing in accordance with the following procedure: 6.1 If the helicopter is already compliant with the SB 189-227, perform HUMS data download from AMMC to DTD. Upload the HUMS data to Heliwise. CAUTION Pay attention to prevent rod rotation, when screwing / un-screwing the castellated nut, holding the rod square end. ### Page 22 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 Page 22 of 37 REVISION: C - April 6, 2020 NOTE Before removal of the TR duplex bearing, take note of its installation orientation marking “OUT” on the outboard visible face. After removal mark “IN” on the inboard opposite face of the TR duplex bearing. Use an indelible pen. 6.2 In accordance with AMP DM 89-A-64-31-05-00A-520A- B, remove the TR duplex bearing. 6.3 Collect the grease leaked from the TR duplex bearing “IN” marked side in a container different from the one used before. 6.4 Take a picture of both faces of the removed TR duplex bearing and send them to PSE (pse_aw189.mbx.aw@leonardocompany.com) before returning the bearing. 6.5 Clean by means of a soft lint-free cloth the housing of the TR duplex bearing, the rod visible part and the internal side of the spider plug. CAUTION Pay attention to prevent rod rotation, when screwing / un-screwing the castellated nut, holding the rod square end. NOTE In case during the installation of control rod nut, after several attempts with different nuts, the minimum required breakaway torque (as required by AMP DM 89-A-64-31-04-00A-720A-A) is not reached, please contact the Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com) to receive dedicated instructions. 6.6 In accordance with AMP DM 89-A-64-31-05-00A-720A- B, install a new TR duplex bearing. 6.7 With reference to Figure 3, restore the slippage marking on the castellated nut from the hinge bracket element to the rod. 7. In case replacement of the TR duplex bearing is required, please return immediately (within 2 days) the removed TR duplex bearing and the collecting containers of the grease to Leonardo Helicopters. Contact the Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com) to receive the proper instructions to return the removed component. ### Page 23 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 REVISION: C - April 6, 2020 Page 23 of 37 8. In accordance with AMP DM 89-A-64-31-01-00A-720A-A, while performing installation of TR pitch links, it is possible to re-protect TR pitch links and the scissors using the following procedure: 8.1 Clean the bolts by means of cleaning solvent. 8.2 Check the bolts looking for corrosion. Contact the Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com) in case of any findings. 8.3 Protect the parts using Tectyl Grade I or Thixoflex Black as a valid alternative. 9. Clean the visible surface of the TR duplex bearing by means of soft lint-free cloth. NOTE When performing the following step allow the sealant to cure for at least 2 hours before the next flight. 10. In accordance with AMP DM 89-A-64-31-03-00A-720A- A, install the spider plug. 11. Return the helicopter to a ready to flight condition and record for compliance with Part V of this Service Bulletin on the helicopter logbook. NOTE In case of any findings, report within 2 days the inspection results along with the available records of the previous checks. 12. Send the attached compliance form and the compile d Table IV to the following mail box: pse_aw189.mbx.aw@leonardocompany.com As an alternative, gain access to My Communications section on Leonardo WebPortal and compile the “Service Bulletin Application Communication”. ### Page 24 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 Page 24 of 37 REVISION: C - April 6, 2020 PA RT VI 1. In accordance with AMP DM 89-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. In accordance with AMP DM 89-A-64-31-04-00A-520A-A, remove the spider and slider assembly. 3. Inspect the visible part of the inboard side of the TR duplex bearing (including the seals) for absence of wear, damages and absence of particles by looking inside the slider cylinder. Record the results on Table V (refer to Figure 11). 4. With reference to Figure 6 lock the slider of the sliding control assembly in a bench vice with padded jaws. 5. Examine the duplex bearing to find roughness in accordance with the following procedure: NOTE • To initiate rotation of the duplex bearing, a break-out force could be necessary. The break- out force is not an indication of roughness. • Relative axial movement between the inner races is acceptable and shall not be considered as a finding. 5.1 Use your fingers to push down on the upper face o f the inner race of the duplex bearing. NOTE Do not release pressure, continue to apply pressure with your fingers during the subsequent step. 5.2 With reference to Figure 6 section A-A Step 1, pu sh the top inner race down and at the same time turn it to feel if there is roughness. 5.3 Put your finger into the duplex bearing until you can pull up the lower face of the inner race. NOTE Do not release pressure, continue to apply pressure with your finger during the subsequent step. 5.4 With reference to Figure 6 section A-A Step 2, pu ll the bottom inner race in the up direction and at the same time turn it to feel if there is roughness. 5.5 Repeat the Step 5.1 thru Step 5.4 at least one time to confirm the results. 5.6 Record the results of the previous steps on Table V (refer to Figure 11). ### Page 25 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 REVISION: C - April 6, 2020 Page 25 of 37 6. If any of the checks performed in the steps 3 and 5 fails proceed with the following step, otherwise skip to step 9. 7. Contact immediately the Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com) to receive further instruction before performing the replacement of the TR duplex bearing in accordance with the following procedure: 7.1 If the helicopter is already compliant with the SB 189-227, perform HUMS data download from AMMC to DTD. Upload the HUMS data to Heliwise. NOTE Before removal of the TR duplex bearing, take note of its installation orientation marking “OUT” on the outboard visible face. After removal mark “IN” on the inboard opposite face of the TR duplex bearing. Use an indelible pen. 7.2 In accordance with AMP DM 89-A-64-31-05-00A-520A- B, remove the TR duplex bearing. 7.3 Collect the grease leaked from the TR duplex bearing “IN” marked side in a container different from the one used before. 7.4 Take a picture of both faces of the removed TR duplex bearing and send them to PSE (pse_aw189.mbx.aw@leonardocompany.com) before returning the bearing. 7.5 Clean by means of a soft lint-free cloth the housing of the TR duplex bearing, the rod visible part and the internal side of the spider plug. NOTE In case during the installation of control rod nut, after several attempts with different nuts, the minimum required breakaway torque (as required by AMP DM 89-A-64-31-04-00A-720A-A) is not reached, please contact the Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com) to receive dedicated instructions. 7.6 In accordance with AMP DM 89-A-64-31-05-00A-720A- B, install a new TR duplex bearing. ### Page 26 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 Page 26 of 37 REVISION: C - April 6, 2020 7. 7 With reference to Figure 3, restore the slippage marking on the castellated nut from the hinge bracket element to the rod. 8. In accordance with AMP DM 89-A-64-31-01-00A-720A-A, while performing installation of TR pitch links, it is possible to re-protect TR pitch links and the scissors using the following procedure 8.1 Clean the bolts by means of cleaning solvent. 8.2 Check the bolts looking for corrosion. Contact the Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com) in case of any findings. 8.3 Protect the parts using Tectyl Grade I or Thixoflex Black as a valid alternative. NOTE In case during the installation of control rod nut, after several attempts with different nuts, the minimum required breakaway torque (as required by AMP DM 89-A-64-31-04-00A-720A-A) is not reached, please contact the Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com) to receive dedicated instructions. 9. In accordance with applicable steps of AMP DM 89-A -64-31-04-00A-720A-A, reinstall the spider and slider assembly. 10. Return the helicopter to a ready to flight condition and record for compliance with Part VI of this Service Bulletin on the helicopter logbook. NOTE In case of any findings, report within 2 days the inspection results along with the available records of the previous checks. 11. In case replacement of the TR duplex bearing is r equired, please return immediately (within 2 days) the removed TR duplex bearing and the collecting containers of the grease to Leonardo Helicopters. Contact the Product Support Engineering (pse_aw189.mbx.aw@leonardocompany.com) to receive the proper instructions to return the removed component. 12. Send the attached compliance form and the compiled Table V to the following mail box: pse_aw189.mbx.aw@leonardocompany.com As an alternative, gain access to My Communications section on Leonardo WebPortal and compile the “Service Bulletin Application Communication”.  Non cancellare mai questo segnalibroNon cancellare mai interruzione sezione ### Page 27 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 REVISION: C - April 6, 2020 Page 27 of 37 ### Page 28 (OCR) • LEONARDO HELICOPTERS DETAIL C DYNAMOMETER 1 ALTERNATIVE APPLICATION DYNAMOMETER 2 SPIDER DETAIL D DYNAMOMETER 2 ORTHOGONAL TO SPIDER DYNAMOMETER 1 (VERTICAL POSITION) DYNAMOMETER 1 (VERTICAL POSITION) DETAIL B TRA SQUARED ROD END SPIDER DYNAMOMETER 2 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 REVISION: C - April 6, 2020 ### Page 29 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 REVISION: C - April 6, 2020 Page 29 of 37 ### Page 30 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 Page 30 of 37 REVISION: C - April 6, 2020 ### Page 31 (OCR) LEONARDO HELICOPTERS Cutting line. Pay attention to not cut the degree Celsius scale. 16mm Limit cutting at the minimum required to obtain 16mm of height. Pay attention to not damage or to expose to the environment the sensitive elements. NOTE Do not use a thermal strip if after having trimmed it, its sensitive element is exposed to air. See below an example of a badly cut strip. THERM 10 Thermal strip layers delamination. NOT acceptable. S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 REVISION: C - April 6, 2020 Page 31 of 37 ### Page 32 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 Page 32 of 37 REVISION: C - April 6, 2020 ### Page 33 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 REVISION: C - April 6, 2020 Page 33 of 37 TABLE I AIRCRAFT S/N SB COMPLIANCE DATE: P/N 6F6730V00331 TRA S/N A/C FH at SB COMPLIANCE DATE: TRA FH at SB COMPLIANCE DATE A/C LANDINGS at SB COMPLIANCE DATE: ACTION Required Obtained PART I CASTELLATED NUT paint mark check NO ROTATION BETWEEN PARTS ### Page 34 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 Page 34 of 37 REVISION: C - April 6, 2020 TABLE II AIRCRAFT S/N SB COMPLIANCE DATE: P/N 4F6430V00551 TR DUPLEX BEARING S/N A/C FH at SB COMPLIANCE DATE: TR DUPLEX BEARING FH at SB COMPLIANCE DATE A/C LANDINGS at SB COMPLIANCE DATE: ACTION Required Obtained PART II TR DUPLEX BEARING wear and damages check NO FINDINGS TR SPIDER axial play check ABSENCE of AXIAL PLAY TR DUPLEX BEARING roughness check FREE AND EASY ROTATION TR DUPLEX BEARING breakaway torque check – Arm blue, clockwise direction 2 N thru 10 N TR DUPLEX BEARING breakaway torque check – Arm yellow, clockwise direction 2 N thru 10 N TR DUPLEX BEARING breakaway torque check – Arm red, clockwise direction 2 N thru 10 N TR DUPLEX BEARING breakaway torque check – Arm white, clockwise direction 2 N thru 10 N TR DUPLEX BEARING breakaway torque check – Arm blue, counterclockwise direction 2 N thru 10 N TR DUPLEX BEARING breakaway torque check – Arm yellow, counterclockwise direction 2 N thru 10 N TR DUPLEX BEARING breakaway torque check – Arm red, counterclockwise direction 2 N thru 10 N TR DUPLEX BEARING breakaway torque check – Arm white, counterclockwise direction 2 N thru 10 N ### Page 35 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 REVISION: C - April 6, 2020 Page 35 of 37 T ABLE III AIRCRAFT S/N SB COMPLIANCE DATE: P/N 4F6430V00551 TR DUPLEX BEARING S/N A/C FH at SB COMPLIANCE DATE: TR DUPLEX BEARING FH at SB COMPLIANCE DATE A/C LANDINGS at SB COMPLIANCE DATE: ACTION Required Obtained PART IV THERMAL STRIP Temperature check TEMPERATURE SHALL NOT R EACH A VALUE EQUAL TO OR ABOVE 121°C. ### Page 36 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 Page 36 of 37 REVISION: C - April 6, 2020 TABLE IV AIRCRAFT S/N SB COMPLIANCE DATE: P/N 4F6430V00551 TR DUPLEX BEARING S/N A/C FH at SB COMPLIANCE DATE: TR DUPLEX BEARING FH at SB COMPLIANCE DATE A/C LANDINGS at SB COMPLIANCE DATE: ACTION Required Obtained PART V TR DUPLEX BEARING Particles check ABSENCE of ANY PARTICLES TR DUPLEX BEARING Grease leakage check ABSENCE of METALLIC PARTICLES ### Page 37 S.B. N°189-237 EMERGENCY ALERT DATE: May 29, 2019 REVISION: C - April 6, 2020 Page 37 of 37 TABLE V AIRCRAFT S/N SB COMPLIANCE DATE: P/N 4F6430V00551 TR DUPLEX BEARING S/N A/C FH at SB COMPLIANCE DATE: TR DUPLEX BEARING FH at SB COMPLIANCE DATE A/C LANDINGS at SB COMPLIANCE DATE: ACTION Required Obtained PART VI TR DUPLEX BEARING Roughness check by fingers FREE AND EASY ROTATION TR DUPLEX BEARING wear, damages and particles check on the inboard side of the bearing NO FINDINGS ### Page 38 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.