As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 4295 - DURING CLIMB-OUT FROM DFW-JAX, THE STABILIZER AND MACH TRIMS DISENGAGED AT APPROXIMATELY 400 FEET. QRH PROCEDURES WERE COMPLIED WITH AND AN EMERGENCY WAS DECLARED. THE AIRCRAFT RETURNED TO DFW AND LANDED SAFELY. MAINTENANCE REMOVED AND REPLACED THE HORIZONTAL STABILIZER TRIM CONTROL UNIT. OPERATIONAL CHECKS GOOD. AIRCRAFT OK FOR SERVICE. (M)