As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE FLIGHT CREW REPORTED THAT THE HEADING AND ATTITUDE ON PDF2 FAILED ON CLIMB OUT FROM AIRPORT. SELECTED HDG&ATT REV. AUTOPILOT WOULD NOT ENGAGE DUE TO LACK OF AHRS INPUT. THE BASE MAINTENANCE TEAM TROUBLESHOT AND FOUND THE NO2 AHRS HAD FAILED. IT WAS REMOVED AND REPLACED WITH A SERVICEABLE UNIT. OPS CHECKS WERE SATISFACTORY AND THE AIRCRAFT WAS RETURNED TO SERVICE.