# SDR SWAA2021112227903

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: October 7, 2021
- Submitted: November 22, 2021
- Operation: Air carrier
- Aircraft: N450WN
- Make and model: Boeing 737*
- Aircraft serial: 32470
- Aircraft time: 58,641 hours, 34,716 cycles
- System (JASC): [5320 · Fuselage Miscellaneous Structure](https://openairdocs.org/jasc/5320)
- Part: Intercostal
- Condition: Corroded
- Location: Fuselage
- Stage of operation: IN
- How discovered: 9
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/SWAA2021112227903

## Discrepancy

CORROSION ON INTERCOSTAL AT AFT CARGO BAY BS771 RBL6 WL154. ; / [01] EVALUATED CORROSION; FOUND TO BE OUT OF LIMITS DUE TO NO LIMITS IN THE SRM AND REQUIRES REPLACEMENT PER SRM 51-10-02-0G-0; [02] REMOVED OLD INTERCOSTAL PER SRM 51-40-02-0G-0; [03] VERIFIED EVALUATED CORROSION; FOUND TO BE OUT OF LIMITS DUE TO NO LIMITS IN THE SRM AND REQUIRES REPLACEMENT PER SRM 51-10-02-0G-0; [04] RECEIVED INTERCOSTAL FROM FORM AND HEAT TREAT PO#841173; [05] LOCATED AND DRILLED NEW INTERCOSTAL AT ACB BS767 - BS787 RBL6 WL154 PER SRM 51-40-05-0G-0 AND DWG 146A8130. APPLIED CHEMICAL CONVERSION COATING AND PRIMER TO NEW INTERCOSTAL PER AMM 51-21-41-370-802; AMM 51-21-72-370-804. OK TO INSTALL; [06] VERIFIED CORRECTIVE ACTION STEPS 4 AND 5. OKAY TO INSTALL; [07] INSTALLED NEW INTERCOSTAL AT ACB BS767 - BS787; RBL16; WL154 PER SRM 51-40-02-0G-0 AND DWG 146A8130; [08] VERIFIED CORRECTIVE ACTION 7.; [09] VERIFIED REPLACEMENT OF INTERCOSTAL. ALL WORK ACCOMPLISHED.

---
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.