What was found
LOST STAB AND MACH TRIM EN ROUTE. REENGAGED AS PER QRH. AFTER 10 MINUTES, THE PROBLEM OCCURRED AGAIN. REENGAGED AND SLOWED TO 250 KIAS. MAINTENANCE DIAGNOSTIC COMPUTER INDICATED HSTCU FAILED. REMOVED AND REPLACED HSTCU IAW 27-41-01.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
LOST STAB AND MACH TRIM EN ROUTE. REENGAGED AS PER QRH. AFTER 10 MINUTES, THE PROBLEM OCCURRED AGAIN. REENGAGED AND SLOWED TO 250 KIAS. MAINTENANCE DIAGNOSTIC COMPUTER INDICATED HSTCU FAILED. REMOVED AND REPLACED HSTCU IAW 27-41-01.