# SDR 20001212SH020

- Type: Service difficulty report (as reported; unverified)
- Difficulty date: November 16, 2000
- Submitted: December 12, 2000
- Operation: Air carrier
- Make and model: Boeing 737*
- System (JASC): [2740 · Stabilizer Control System](https://openairdocs.org/jasc/2740)
- Part: Spring
- Part number: 69778551
- Condition: Broken
- Location: Horiz Stab Trim
- Component: Auxiliary Brake, Boeing
- Component part number: 654997025
- Stage of operation: IN
- How discovered: V
- Nature of condition: O
- Precautionary procedure: K
- FAA source: FAA Service Difficulty Reporting System (https://sdrs.faa.gov/)
- Page: https://openairdocs.org/sdr/20001212SH020

## Discrepancy

SPRINGS, PN 69-77855-1, ARE BROKEN IN THE AUXILIARY BRAKE SYSTEM CAUSING THE UNIT TO BIND AND JAM.  POSSIBLE CAUSE, IMPROPER HEAT-TREATING, AUSTENITE, FATIGUE AND INCREASED SPRING COIL STRESSES.  SPRINGS, PN 69-77855-1, ARE TO BE REPLACED WITH, PN 69-77855-2, SPRINGS ON ACTUATOR ASSEMBLIES MANUFACTURED PRIOR TO S/N KEO1730 PER BOEING SL 737-SL-27-090-B.  (X)

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