What was found
ELEVATOR FEEL CAUTION LIGHT ILLUMIINATED AT TOP OF CLIMB AT FL250. IAS WAS NOT MISMATCHED. RETURNED TO FIELD. LANDING UNEVENTFUL. R & R THE NR 1 AIR DATA COMPUTER (ADC) AS A PRECAUTIONARY MEASURE IAW AMM TASK 6341101. OPS CHECKED GOOD. PERFORMED A PITOT/STATIC SYS LEAK CHECK IAW MX 6341102. CHECKED GOOD. CDS INDICATED ADC FAILURE, ALSO PILOTS PFD SHOWED ATT/HDG/IAS FAIL MSG. C/W FIM 34-11-00-810-873 & 27-30-00-810-802. R2 NR 1 ADU. OPS CHECKED GOOD. ALL FAULTS & CAUTION LIGHTS CLEARED.