# SDR SIMA202608031003

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: July 31, 2026
- Submitted: August 3, 2026
- Operation: Air carrier
- Aircraft: [N254NN](https://openairdocs.org/aircraft/N254NN), 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: 17000650
- Aircraft time: 23,756 hours, 16,022 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: A/C Pack
- Condition: Failed
- Location: Nr 1
- Stage of operation: DE
- How discovered: O
- Nature of condition: B
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/SIMA202608031003

## Discrepancy

THROUGH FL 210 FIRECRACKER SMELL AND THIN VISIBLE SMOKE. SMOKE WENT AWAY AFTER 30 SECONDS BUT ODOR REMAINED. SAME CONDITIONS IN PAX CABIN AS REPORTED BY FLIGHT ATTENDANTS. GOT XBLEED SWITCH OFF MESSAGE DURING DESCENT. BRIEFLY GOT NAV 1 FAIL ON MCDU. PAX AND FA REPORTED A VIBRATION & AN UNIDENTIFIED SOUND FROM THE CLOSET AREA. DURING DESCENT ALSO GOT THE HISSING SOUND FROM THE CA DV WINDOW THAT WENT AWAY ABOUT 100 FT. ON THE GROUND AFTER APU START & ENG 2 SHUT DOWN , THE XBLEED SWITCH OFF MESSAGE RETURNED. CONFIGURATION WAS NORMAL FOR THE PHASE OF FLIGHT. CLIMB 1, APU OFF. IN ORDER TO COMPLY WITH TRIAD WORK, PERFORMED FIM TASK 21-20-00-810-801-A & FOUND PACK 1 FAILED ON EICAS, DURING COMPLIANCE. FOLLOWED ASSOCIATED FIM TASK 21-51-00-810-833-A. DURING COMPLETION OF THE FIM, CONDUCTED OPS TEST OF COOLING PACKS IAW AMM 21-00-00/200 AND FOUND VIOLENT BANG IN PACK 1 SYSTEM IN FWD SECTION OF ACM. AFTER DEACTIVATING PACK 1 FOR TROUBLESHOOTING PURPOSES, CONTINUED TO RUN ACFT ON PACK 2 FOUND SMOKE DISSIPATED & NO ABNORMAL NOISE HEARD. MEL 21-44 WAS ISSUED TO DEACTIVATE PACK 1.  REF AML 107202210 FOR DEFERRAL OF PACK 1. REF AML PAGE 107202218 FOR ACTION TAKEN OF THE CA DV WINDOW HISSING NOISE.

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