SDR 20000406SH007

Service difficulty report · Spring · Boeing 737*

Difficulty date: January 31, 2000
Submitted: April 6, 2000
Operation: General aviation
Make and model: Boeing 737*
System (JASC): 2742 · Stabilizer Actuator
Part: Spring
Part number: 69778551
Condition: Cracked
Location: Trim Actuator
Part time: 50,559 hours
Component: Horiz Stab Trim Act · Boeing
Component part number: 65C347512
Stage of operation: IN
How discovered: O
Nature of condition: O
Precautionary procedure: K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

SPRINGS, PN 69-77855-1, ARE BROKEN IN THE AUXILIARY BRAKE SYSTEM. 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)