As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STAB CHANNEL 1 HSTCU DISENGAGED DURING FLIGHT, UNABLE TO RE-ENGAGE. MACH TRIM FAILURE INFLIGHT DESCENDING FROM 11000 MSL AND SLOWING FROM 280 KIAS, ABLE TO RE-ENGAGE VIA QRH. REMOVED & REPLACED HSTA IAW MM 27-42-01. REMOVED & REPLACED MCU IAW 27-42-05. OPS CHECKS GOOD IAW 27-41-00. P/N OFF/ON 7062-3, S/N OFF 606, S/N ON 734.