What was found
AFTER SWITCHING FROM AUTOPILOT A TO B, AUTOPILOT B DISENGAGED AFTER 5 SECONDS. NEITHER AUTOPILOT WOULD RE-ENGAGE IN CMD OR CWS AFTER AUTOPILOT A & B INOPERATIVE. ACFT GROUNDED. PERFORMED DFCS BITE PROCEDURE IAW FIM 22-11-TASK 801, FOUND FAULT CODE 22-11127, CHANNEL A ELEVATOR ACTUATOR PRESSURE LCL INV. PERFORMED FCC EXCHANGE IAW FIM 22-11, TASK 820, BOTH FCC INSTALLATION TEST PASSED. IAW FIM 22-13-TASK 806, FAULT DEEMED INTERMITTENT. SWAPPED FCC BACK TO ORIGINAL POSITIONS AND ALL TEST PASSED, REF AMM 22-11-33. ACFT OK FOR SERVICE.