# SDR AALA202603026988

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: February 27, 2026
- Submitted: March 3, 2026
- Operation: Air carrier
- Aircraft: [N921AN](https://openairdocs.org/aircraft/N921AN), registered now
- Make and model: Boeing 737823
- Aircraft serial: 29522
- Aircraft time: 71,104 hours, 29,653 cycles
- System (JASC): [2150 · Cabin Cooling System](https://openairdocs.org/jasc/2150)
- Part: Control Valve
- Condition: Faulty
- Location: Zone 100
- Stage of operation: CR
- 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/AALA202603026988

## Discrepancy

AIRCRAFT WAS GROUNDED: ON ALL 3 LEGS WHEN STARTING NUMBER 2 ENGINE WE GET A VERY STRONG FUEL AND EXHAUST ODOR IN THE CABIN AND FLIGHT DECK AS SOON AS FUEL IS INTRODUCED. THE ODOR CONTINUES THROUGH ENGINE START UNTIL RIGHT PACK IS TURNED ON, THEN THE ODOR DISSIPATES QUICKLY. WE NOTICED THAT AROUND 22% N2 THE ENGINE SEEMS TO STRUGGLETO GET TO 25% WHERE FUEL IS INTRODUCED, FOLLOWED BY THE STRONG ODOR. REMOVED AND REPLACED PACK FLOW CONTROL VALVE. PER AMM 21-51-00.

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