As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RT SIDE ITT INDICATOR FELL ABOUT 300 DEGREES APPROXIMATELY 20 MIN AFTER DEPARTURE SHOWING AT 530 VS 830. ALL OTHER ENGINE PARAMETERS WERE NORMAL BOTH ANALOG AND DIGITAL SHOWED THE DROP. AC RETURNED TO DEPARTURE, MAINTENANCE PERFORMED ITT CAL CHECK OF RT ENG FOUND ITT GAGE GIVING ERRATIC READINGS REMOVED AND REPLACED ITT GAUGE ALL CHECKS GOOD.