 | GEnx-1B SERVICE BULLETIN - 72-0108 R00 | Revised: 11/12/2012 |
| SB 72-0108 R00 ENGINE - Combustor Diffuser Assembly (72-41-00) - Introduction of New 0.375 inch (9.53 mm) Diameter Screw Insert | Issued: 11/12/2012 | |
| GEnx-1B SERVICE BULLETIN - 72-0108 R00 | Revised: 11/12/2012 |
| SB 72-0108 R00 ENGINE - Combustor Diffuser Assembly (72-41-00) - Introduction of New 0.375 inch (9.53 mm) Diameter Screw Insert | Issued: 11/12/2012 | |
| 1. | PLANNING INFORMATION |
| A. | Effectivity |
|
| This Service Bulletin is applicable to these GEnx-1B engines: |
| • |
|
| This Service Bulletin has been introduced in production to these GEnx-1B engines: |
| • |
|
| These serial numbers are the best available data. |
| The screw 0.375 inch (9.53 mm) diameter insert P/N 1693M83P11 and the locking ring P/N 1689M74P05 are affected by this Service Bulletin. |
| B. | Description |
| This Service Bulletin introduces a new 0.375 inch (9.53 mm) diameter screw insert and locking ring to the combustion case to improve the case durability. The new insert P/N 1693M83P14 and locking ring P/N 1689M74P09 apply only to the 0.375 inch (9.53 mm) diameter insert locations on the case. |
| By this document it is recommended that early engines defined herein, with prior inserts and lock rings, be revised to install the new inserts and lock rings at first opportunity. |
| C. | Compliance |
| Category 5 |
| GE recommends that you do this Service Bulletin as soon as the combustion case is removed from the engine and exposed at the piece part level. |
| This Service Bulletin is offered to improve the reliability or performance of your GE product, or to help prevent the occurrence of the event or condition described in this Service Bulletin. If the operator elects not to participate in the bulletin, that decision will be taken into consideration by GE in evaluating future product performance issues that may arise in the operators fleet. |
| D. | Concurrent Requirements |
| None. |
| E. | Reason |
| (1) | Objective: |
| To introduce new parts, improve reliability, improve maintainability, and remove parts from service. |
| (2) | Condition: |
| The current screw insert and locking ring designs are subject to damage during maintenance and their replacement on wing is more difficult. All combustor cases P/N 2303M23G01, 2417M03G01, 2417M02G01, 2405M02G01, 2303M23G11, and 2303M23G19 that have the early inserts and locking rings need to be replaced with the new parts to improve their reliability and maintainability. The new insert and locking ring need to be released to the EIPC to support replacement. |
| (3) | Cause: |
| The current screw insert length is insufficient, resulting in seizing of the bolt due to exposure to high temperatures within the case. Also, the engagement between the insert serration and the locking ring serration is insufficient. |
| (4) | Improvement: |
| The new screw insert and locking ring designs have improved engagement at the interface. The new insert design is longer to make sure the bolt threads do not protrude beyond the insert end, includes an improved counterbore at the top of the insert to eliminate a thin wall condition that occurs at disassembly, and has an associated locking ring change that improves fit-up and allows swaging with the new counterbore. All these changes will reduce on wing replacement caused by damage during maintenance. |
| (5) | Substantiation: |
| Substantiation is by test. |
| F. | Approval |
| This Service Bulletin has been reviewed by the FAA and the repair(s) and modification(s) herein comply with the applicable Federal Aviation Regulations and are FAA APPROVED for installation in the model(s) listed in this Service Bulletin. |
| G. | Manpower |
| After you get access to the combustion case, you will need approximately 2 man-hours to do the replacement portion of this Service Bulletin. |
| H. | Weight and Balance |
| The complete compliance with this Service Bulletin increases weight by 0.100 lb (0.045 kg). |
| I. | References (Use the latest version of these documents) |
| GEK 112862, GEnx-1B Cleaning, Inspection, and Repair Manual (CIR) |
| GEK 112864, GEnx-1B Engine Illustrated Parts Catalog (EIPC) |
| NOTE: |
|
| J. | Publications Affected |
| GEK 112862, GEnx-1B Cleaning, Inspection, and Repair Manual (CIR) |
| GEK 112864, GEnx-1B Engine Illustrated Parts Catalog (EIPC) |
| K. | Interchangeability |
| Interchangeable as a set. Replace all 0.375 inch (9.53 mm) diameter inserts on the combustion case at this time. |
| L. | Software Accomplishment Summary |
| Not applicable. |
| 2. | MATERIAL INFORMATION |
| A. | Material - Price and Availability |
| (1) | Parts necessary to do this Service Bulletin: |
|
| NOTE: |
|
| (2) | Other Spare Parts: |
| None. |
| (3) | Consumables: |
| None. |
| B. | Industry Support Information |
| None. |
| C. | Configuration Chart |
|
| Operation Codes RE=Replace RM=Remains |
| Change Code 4=Interchangeable as a set. |
| Support Code A=Old parts will no longer be supplied. |
| D. | Parts Disposition |
| Use old parts for on wing maintenance support on engines that have not been modified. |
| E. | Tooling - Price and Availability |
| None. |
| 3. | ACCOMPLISHMENT INSTRUCTIONS |
| A. | General |
| (1) | Removal and installation instructions of the screw insert and locking ring have not changed. Refer to the GEnx-1B CIR, 72-41-01, REPAIR 001 for instructions to replace the 0.375 inch (9.53 mm) diameter inserts. |