What was found
FLT 386 - DTW - AUTOPILOT WILL NOT STAY ENGAGED, TRIPS OFF EVERY 2-3 MINUTES, DFGS NR 1 OR NR 2, ALT TRIM OK. FOUND ELEVATOR POWER SERVO FAIL IN FLIGHT FAULT REVIEW. REMOVED AND REPLACED ELEVATOR SERVO IAW MM 21-12-01, PERFORMED AUTO PILOT CHECK AND RTS. OPS CHECK GOOD IAW MM 22-10-00 AND 22-01-01. (M)