As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 5257 - AFTER TAKEOFF RADAR ALTIMETER BECAME ERRATIC, FLUCTUATING FROM 300 TO 3000 FT. A TERRAIN ALERT WAS ALSO RECEIVED AT ABOUT 2000 FT. AIRCRAFT LANDED SAFELY BACK AT CVG. COULD NOT DUPLICATE ON GROUND. OHMED AND MEGGED CABLES, NO DEFECTS NOTED.