As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ELEVATOR TRIM ACTUATOR FREEZES UP AT HIGH ALTITUDES. SIGNIFICANT SNAP-BACK WITH BOTH MANUAL AND ELECTRIC TRIM INPUTS, 17,000 FT AND HIGHER. REPLACED LEFT AND RIGHT ELEVATOR TRIM ACTUATORS WITH SERVICEABLE UNITS IAW AMM 27-32-02. OPS CHECK GOOD. P/N: 5299-1.