As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PDX - ON FLIGHT 2505, RETURNED TO FIELD. FO'S PFD SHOWED AMBER IAS AND INDICATED AIRSPEED WAS VARING INCORRECTLY. MAINTENANCE REMOVED AND REPLACED NR 2 DADC. PERFORMED OPERATIONAL TEST OF NR 2 DADC, OPERATIONAL TEST GOOD. AIRCRAFT RETURNED TO SERVICE.