As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: DURING CLIMB IAS DISAGREE MESSAGE. FIRST OFFICERS AIRSPEED INDICATED 130 KNOTS SLOW AT ALTITUDE. DURING DESCENT THROUGH 20,000 AIRSPEED RETURNED TO NORMAL THROUGH THE REST OF THE FLIGHT. MAINTENANCE FOUND FAULT MESSAGES ON AIR DATA INERTIAL REFERENCE UNIT NR 2 (ADIRU) AND REPLACED IT IAW AMM 34-21-00. SATISFACTORY OPERATIONAL CHECKS WERE ACCOMPLISHED.