# SDR CALA2026042715737

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: April 23, 2026
- Submitted: April 27, 2026
- Operation: Air carrier
- Aircraft: [N37298](https://openairdocs.org/aircraft/N37298), registered now
- Make and model: Boeing 737824
- Aircraft serial: 34004
- Aircraft time: 59,162 hours, 22,165 cycles
- System (JASC): [2740 · Stabilizer Control System](https://openairdocs.org/jasc/2740)
- Part: Computer
- Part number: 8221604101
- Part serial: 18C2VD
- Condition: Failed
- Location: Fcc B
- Part time: 39,612 hours, 15,188 cycles
- Stage of operation: DE
- How discovered: O
- Nature of condition: F
- Precautionary procedure: O
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/CALA2026042715737

## Discrepancy

RA FLAG AND AUTOPILOT DISCONNECT. FO SIDE  NOT ABLE TO USE NOSE UP TRIM.F/O STAB TRIM SWITCHES NOSE UP TRIM INOP.  ACCOMPLISHED BASIC GVI OF VISIBLE CONTROL CABLES IN FWD&AFT E&E BAYS, WHEEL WELL, AND JACKSCREW COMPARTMENT, NO DEFECTS NOTED.  FOUND EXCESSIVE MOISTURE ON STAB TRIM ACTUATOR BUT NO OTHER OBVIOUS DEFECTS ADD EMP:U348947 NOTED.  FOUND NO CBS POPPED IN COCKPIT OR E&E BAY.  FURTHER T/S REQUIRED. LOOKED AT THE AFCS FAULT HISTORY AND FOUND 3 IN FLIGHT FAULTS #2 RAD ALT. ON CHANNEL B, NONE FOR CHANNEL A. SEE PHOTOS. REMOVED FCC B AND FCC A IN REFERENCE TO AMM 22-11-33-000-801 TO FOM. REM OVED #2 RAD ALT IN REFERENCE TO 34-33-21-000-801 TO FOM. CHECK W IRING FOR CONNECTOR D10137B PIN B4 AND A4 TO CONNECTOR D3669B PI N B2 TO B3. WIRING CHECKED GOOD, NO SHORTS OR OPENS. SUGGEST REP LACING FCC B DUE TO CORROSION ON THE BACK SIDE OF LRU. PHOTOS SSM 34-33-21-104 USED FOR RING OUTS. INSTALLED #2 RAD ALT IN REFERENCE TO B737 AMM 34-33-21-400-801. INSTALLED FCC A IN REFERENCE TO 22-11-33-400-801. CAT REQUIRED FOR OPS CHECK PERFORMED LOW RANGE RADIO ALTIMETER (LRRA) SYSTEM - OPERATIONAL TESTREFERENCE: TASK 34-33-00-710-801. TEST PASSED. PERFORMED BITE ON BOTH R/TS. NO FAULTS. SEE LP 8653356 FOR OPS CHECK OF STABILIZER TRIM FUNCTIONS. REMOVED AND REPLACED.

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