# SDR AALA202601128379

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: January 9, 2026
- Submitted: January 13, 2026
- Operation: Air carrier
- Aircraft: [N917NN](https://openairdocs.org/aircraft/N917NN), registered now
- Make and model: Boeing 737823
- Aircraft serial: 29572
- Aircraft time: 37,996 hours, 16,384 cycles
- System (JASC): [2751 · Trailing Flap Position Indicating System](https://openairdocs.org/jasc/2751)
- Part: Bypass Valve
- Part number: AV13J5144
- Part serial: T61694
- Condition: Failed
- Location: Flap Sys
- Part time: 5,081 hours, 2,492 cycles
- Stage of operation: AP
- How discovered: O
- Nature of condition: F, J
- Precautionary procedure: A
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/AALA202601128379

## Discrepancy

AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED DUE TO: DURING APPROACH, THE FLAPS DID NOT EXTEND PAST 5; AIRCRAFT EMERGENCY LANDED SAFELY AT BOS. REMOVE AND REPLACED LEFT FLAP POSITION TRANSMITTER (AALA202601126925), PER J/C 08C00027012. ALSO, REMOVE AND REPLACED TRAILING EDGE BYPASS VALVE (AALA202601128379), PER AMM 27-51-02. OPERATIONAL TESTS GOOD.

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