# SDR C77A2019091300007

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: September 13, 2019
- Submitted: September 13, 2019
- Operation: Air carrier
- Aircraft: [N613CZ](https://openairdocs.org/aircraft/N613CZ), registered now
- Make and model: Emb ERJ 170-200 LR
- Registry model: [EMB ERJ 170-200 LR](https://openairdocs.org/model/embraer-s-a-erj-170-200-lr) (OpenAirDocs)
- Aircraft serial: 17000203
- Aircraft time: 31,713 hours, 19,483 cycles
- System (JASC): [5330 · Fuselage Main, Plate/Skin](https://openairdocs.org/jasc/5330)
- Part: Doubler
- Part number: 17066931001
- Condition: Corroded
- Location: Fuselage
- Stage of operation: IN
- How discovered: V
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/C77A2019091300007

## Discrepancy

DURING BASIC CHECK, CORROSION DAMAGE WAS DISCOVERED DURING INSPECTION ON THE CENTER FUSELAGE III WASTE BOX SKIN DOUBLER, P/N 170-66931-001, ALONG THE INNER EDGES OF THE DOUBLER (REFERENCE PHOTO 1 FOR DETAILS).  THE CORROSION DAMAGE WAS BLENDED WITH THE DEEPEST POST-BLENDOUT AREA MEASURING APPROXIMATELY 
2.561 INCHES X 0.842 INCHES TO A MAXIMUM DEPTH OF 0.029 INCHES. THREE BLENDED AREAS EXCEED THE ALLOWABLE DAMAGE LIMITS PROVIDED IN SRM PART II 53-23-60/AD01.  
THIS EO IS BEING ISSUED TO PROVIDE INSTRUCTIONS TO ACCOMPLISH THE PERMANENT REPAIR OF THE CORRODED CENTER FUSELAGE III WASTE BOX SKIN DOUBLER, P/N 170-66931-001, BY REMOVING AND REPLACING THE CORRODED PART.  PART REPLACEMENT WILL BE ACCOMPLISHED IN ACCORDANCE WITH THE DRAWINGS LISTED IN TABLE 2 AND SRM CHAPTER 51 STANDARD PRACTICES.  SUPPLEMENTAL FOLLOW-ON INSPECTIONS ARE NOT REQUIRED FOR DIRECT REPLACEMENT OF THE CENTER FUSELAGE III WASTE BOX SKIN DOUBLER.  BECAUSE THE CENTER FUSELAGE III WASTE BOX SKIN DOUBLER IS A PSE, ACCOMPLISHMENT OF THIS EO HAS BEEN CLASSIFIED BY ENGINEERING AS A MAJOR REPAIR DUE TO THE COMPLEXITY OF ITS REPLACEMENT.  EO E175-53MR-447 IS BEING ACCOMPLISHED BY WO 2719873.

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