# Embraer Temporary Revision 12-3: No revision named - Rights: © Embraer S.A. Filed by the FAA in regulations.gov docket FAA-2017-0697, the docket of AD 2017-21-09. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Embraer Temporary Revision 12-3](https://openairdocs.org/service-documents/embraer/tr-12-3.md) - Title as filed: TR 12-3_Model 170 and 175_Task 53-10-001-0005 MRB1621 - Pages: 6 - PDF: https://openairdocs.org/files/sha256/14/bf/14bf0fc5cd2610e4c069d85ad509d1aafb90f2d79f5226d3ba606bf3a1c4317c - Page: https://openairdocs.org/service-documents/embraer/tr-12-3/file/14bf0fc5cd26 ## Text Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 Embraer 170/175 - MRB-1621 TR12-3 - Sep 19/16 Page 1 of 6 Copyright © by Embraer S.A. All rights reserved – See title page for details. TEMPORARY REVISION MRB - TEMPORARY REVISION No. 12-3 TO: HOLDERS OF PUBLICATION No. MRB-1621 - "MAINTENANCE REVIEW BOARD REPORT", APPLICABLE TO EMBRAER ERJ 170-100 AND ERJ 170-200 AIRCRAFT MODELS. This Temporary Revision (TR) is to address technical changes on MRB Report 1621 Revision 12 - Appendix A - Part 2 - Airworthine ss Limitation Inspections (ALI), including additional information to TR 12-1 already published. REASON: M RB- 1621 Appendix A - Part 2 - Airworthiness Limitation Inspections (ALI) - Structures is being revised in order to comply wit h requirements RBAC §26.21 (Amendment 01) and Title 14 CFR §26.21 (Amendment 26-6) making available the defined ISP and SMP. FILLING INSTRUCTIONS: Inse rt MRB TR 12-3 pages 1 and 2, facing MRB-1621 Appendix A - Part 2 - Airworthiness Limitation Inspections (ALI) - Structures, Introduction, on page 1 of 2. This TR includes additional information to the Item "2.Limit of Validity (LOV) and Widespread Fatigue Damage (WFD)" published in TR 12-1. NEW ITEM: 2. Limit of Validity (LOV) and Widespread Fatigue Damage (WFD) This item follows the requirements of RBAC §26.21 (Emenda 01) and Title 14 CFR §26.21 (Amendment 26-6) in order to provide the Limit of Validity of the engineering data that supports the structural maintenance program (LOV). These regulations define the need of a Limit of Validity corresponding to the period of time, stated as a number of total accum ulated flight cycles or flight hours or both, during which it is demonstrated that Widespread Fatigue Damage (WFD) will not occur in the airplane. The LOV listed below supports the operator for complying with current applicable RBAC 121 and 129 as well as Title 14 CFR Part 121 and 129 requirements. NOTE: The Limit of Validity is applicable only for aircraft operating under ANAC or FAA regulations. Model Limit of Validity (LOV) EMBRAER 170 ALL 80,000 FC or 106,400 FH whichever occurs first EMBRAER 175 ALL 80,000 FC or 106,400 FH whichever occurs first ### Page 2 Embraer 170/175 - MRB-1621 TR12-3 - Sep 19/16 Page 2 of 6 Copyright © by Embraer S.A. All rights reserved – See title page for details. TEMPORARY REVISION There are maintenance actions mandatory to support the LOV. The maintenance actions include structural inspections and/or struc tural modifications. (a) Structural Inspections: Tasks with note "WFD" (Widespread Fatigue Damage) are the Structural Inspections defined to ensure the compliance with RBAC §26 .21 (E menda 01) and Title 14 CFR §26.21 (Amendment 26-6). These Structural Inspections were developed in order to preclude the Wide spread Fatigue Damage in the airplane. "Inspection Start Point (ISP) - The point in time when special inspections of the fleet are initiated because of a specific pro bab ility of having a multiple site damage/multiple element damage condition. For tasks with note WFD, the ISP is the threshold, or the first In terval for tasks with no threshold. (b) Structural modifications: The structural modifications are available through Service Bulletins. The SMP represents the maximum point in time that the Service B ulletins must be accomplished. Table 1 brings all structural modifications and their respective SMP. "Structural modification point (SMP) - The point in time when a structural area must be modified to preclude WFD. Table 1 - STRUCTURAL MODIFICATION POINT Structural modification Structural modification point SB 170-53-0051 38,931 FC ### Page 3 Embraer 170/175 - MRB-1621 TR12-3 - Sep 19/16 Page 3 of 6 Copyright © by Embraer S.A. All rights reserved – See title page for details. TEMPORARY REVISION MRB - TEMPORARY REVISION No. 12-3 TO: HOLDERS OF PUBLICATION No. MRB-1621 - "MAINTENANCE REVIEW BOARD REPORT", APPLICABLE TO EMBRAER ERJ 170-100 AND ERJ 170-200 AIRCRAFT MODELS. This Temporary Revision (TR) is to address technical changes on MRB Report 1621 Revision 12 - Appendix A - Part 2 - Airworthine ss Limitation Inspections (ALI) REASON: M RB- 1621 Appendix A - Part 2 - Airworthiness Limitation Inspections (ALI) - Structures is being revised in order to comply wit h requirements RBAC §26.21 (Amendment 01) and Title 14 CFR §26.21 (Amendment 26-6) making available the defined ISP and SMP. FILLING INSTRUCTIONS:Insert MRB TR 12-3 pages 3 and 4, facing MRB 1621 Appendix A - Part 2 - Airworthiness Limitation Inspections (ALI) - Structures, chapter 53 page 1 of 25. FROM: TO: MRBR Task Number Type Category Title Description Applicability T: Threshold I: Interval 53-10-001-0003 SDI FORWARD PRESSURE BULKHEAD AT FORWARD FUSEL AGE - INTERNAL Special Detailed Inspection (Eddy Current) of Forward Pr essure Bulkhead Web Aft Face, around of the Vertical and Transversal Beams attachments - Internal Side of Fuselage. PRE-MOD SB 170-53-0051 T: 30000 FC I: 25833 FC MRBR Task Number Type Category Title Description Applicability T: Threshold I: Interval 53-10-001-0003 SDI FORWARD PRESSURE BULKHEAD AT FO RWARD FUSELAGE - INTERNAL Special Detailed Inspection (Eddy Current) of Forward Pres sure Bulkhead Web Aft Face, around of the Vertical and Transversal Beams attachments - Internal Side of Fuselage. ON ACFT PRE-MOD SB 170- 53-0051 AND OPERATING UNDER EASA OR TCCA CERTIFICATION T: 30000 FC I: 25833 FC ### Page 4 Embraer 170/175 - MRB-1621 TR12-3 - Sep 19/16 Page 4 of 6 Copyright © by Embraer S.A. All rights reserved – See title page for details. TEMPORARY REVISION THIS PAGE INTENTIONALLY LEFT BLANK ### Page 5 Embraer 170/175 - MRB-1621 TR12-3 - Sep 19/16 Page 5 of 6 Copyright © by Embraer S.A. All rights reserved – See title page for details. TEMPORARY REVISION MRB - TEMPORARY REVISION No. 12-3 TO: HOLDERS OF PUBLICATION No. MRB-1621 - "MAINTENANCE REVIEW BOARD REPORT", APPLICABLE TO EMBRAER ERJ 170-100 AND ERJ 170-200 AIRCRAFT MODELS. This Temporary Revision (TR) is to address technical changes on MRB Report 1621 Revision 12 - Appendix A - Part 2 - Airworthine ss Limitation Inspections (ALI) REASON: M RB- 1621 Appendix A - Part 2 - Airworthiness Limitation Inspections (ALI) - Structures is being revised in order to comply wit h requirements RBAC §26.21 (Amendment 01) and Title 14 CFR §26.21 (Amendment 26-6) making available the defined ISP and SMP. FILLING INSTRUCTIONS:Insert MRB TR 12-3 pages 3 and 4, facing MRB 1621 Appendix A - Part 2 - Airworthiness Limitation Inspections (ALI) - Structures, chapter 53 page 1 of 25. NEW TASK: MRBR Task Number Type Category Title Description Applicability T: Threshold I: Interval 53-10-001-0005 DET FORWARD PRESSURE BULKHEAD AT FORWARD FUSE LAGE - INTERNAL Detailed Inspection of Forward Pressure Bulkhead Web Aft F ace, around of the Vertical and Transversal Beams attachments - Internal Side of Fuselage. NOTE: WFD. ON ACFT PRE-MOD SB 170- 53-0051 AND OPERATING UNDER ANAC OR FAA CERTIFICATION T: 25954 FC I: 6489 F C ### Page 6 Embraer 170/175 - MRB-1621 TR12-3 - Sep 19/16 Page 6 of 6 Copyright © by Embraer S.A. All rights reserved – See title page for details. TEMPORARY REVISION THIS PAGE INTENTIONALLY LEFT BLANK --- 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.