What was found
ELECTRIC TRIM FAILED IN FLIGHT. NOTHING WAS INDICATED ON ANY OF THE SCREENS THAT THE TRIM WAS NOT WORKING. AUTOPILOT STILL WORKED NORMALLY. DURING APPROACH, WHEN FLAPS WERE SELECTED TO 15 DEGREES OR GREATER, THE ELECTRIC TRIM WOULD START TO WORK NORMAL AGAIN. WHILE TAXING IN, WHEN THE FLAPS WERE SELECTED TO 0, THE TRIM WOULD NOT WORK AGAIN. EVERY TIME WE SELECTED THE FLAPS BACK TO 15 DEGREES, THE TRIM WOULD WORK AGAIN. R & R ELEVATOR TRIM SERVO. OPS CHECKED SATISFACTORY.