# SDR C77A2018120300001

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: December 3, 2018
- Submitted: December 3, 2018
- Operation: Air carrier
- Aircraft: N637CZ
- Make and model: Emb ERJ 170-100 LR
- Registry model: [EMB ERJ 170-100 LR](https://openairdocs.org/model/embraer-erj-170-100-lr) (OpenAirDocs)
- Aircraft serial: 17000256
- Aircraft time: 26,972 hours, 16,204 cycles
- System (JASC): [5511 · Horizontal Stabilizer, Spar/Rib](https://openairdocs.org/jasc/5511)
- Part: Rib
- Part number: 17062642002
- Condition: Cracked
- Location: Horizontal Stab
- Component: Horizontal Stab, Emb
- Component part number: 17062000473
- 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/C77A2018120300001

## Discrepancy

THIS EO PROVIDES INSTRUCTIONS TO COMPLY WITH THE INSTRUCTIONS THAT ARE SPECIFIC TO THE RH HORIZONTAL STABILIZER FROM
SB 170-55-0014, WHICH ACCOMPLISHES A STRUCTURAL MODIFICATION THAT CONSISTS OF REPLACING HORIZONTAL STABILIZER RIBS
10A, 11A, AND 12A WITH NEW, REINFORCED RIBS. THIS MODIFICATION IS DESIGNED TO HELP PREVENT POSSIBLE CRACKS ON THE
HORIZONTAL STABILIZER CENTER BOX RIBS AND TO REACH THE AIRCRAFT ECONOMICAL FATIGUE LIFE. COMPASS ENGINEERING HAS
CLASSIFIED THIS MODIFICATION AS A MAJOR ALTERATION. ONE OR MORE OF THE RIBS THAT ARE BEING REPLACED AS PART OF THE
SERVICE BULLETIN WERE FOUND CRACKED DURING AN INSPECTION WHILE AT BASIC CHECK. BY ACCOMPLISHING SB 170-55-0014,
THIS EO ALSO PROVIDES A REPAIR BY REPLACEMENT OF THE AFFECTED RIB(S). COMPASS ENGINEERING HAS CLASSIFIED THIS REPAIR
AS A MAJOR REPAIR. THIS EO IS BEING MADE EFFECTIVE TO ALL DELTA AIRCRAFT FOR WHICH SB 170-55-0014 IS APPLICABLE, BUT
A MAXIMO EVENT WILL ONLY BE GENERATED FOR AN AIRCRAFT WHEN ONE OR MORE RIBS ARE FOUND CRACKED. THE
ACCOMPLISHMENT INSTRUCTIONS OF THIS EO WERE DERIVED FROM EMBRAER SERVICE BULLETIN 170-55-0014; THEREFORE, A COPY
OF THIS SB IS NOT NEEDED TO ACCOMPLISH THIS EO.

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