What was found
IAS DISAGREE MESSAGE SHOWS ON AIRPSEED DISPLAY FIRST OFFICER''S A/S DISAGREE ILLVM FL370 F/O A/S UNRELIABLE WENT TO OVERSPEED TH EN DROPPED TO 45 IN DESC. PER FIM TASK 31-62-810-876, PERFORMED INITIAL EVALUATION, ADIRS FIM TASK 34-21-00, NO OTHER FAULTS NOTED DURING INITIAL EVALUATION, REMOVED AND REPLACED #2 ADIRU AS A PRECAUTION, PERFORMED ADIRS OPS TEST AND LAND VERIFY TEST IAW AMM 22-11-00.