What was found
AT CRUISE ALTITUDE 290 EICAS MSG IAS DISAGREE FOUND FO AIRSPEED 10KTS DIFFERENT THAN CAPTS AND ALT AND FO ALTIMETER OFF 250 FROM CAPT€™S AND ALT SELECTED ALT AIRDATA ON FO€™S SIDE AND ALL INDICATIONS T/S W/REF TO FIM 34-12 STEPS 1 AND 2 . FOUND RIGHT ADC FAULTED , CHANGED RIGHT ADC W/REF TO AMM 34-12-01. MCDP CURRENT FAULT ADC RIGHT COMPUTER CLEARED AND OPERATIONAL TESTS PASS. EEC FAULTS VERIFIED CAUSE BY ADC RIGHT FAILURE BY LEFT EEC D6 FAULT CODE REF AMM 73-21-00. ALL WORK PERFORMED BY CAT QUAILIFIED MECH. SYSYTEMS OK FOR SERVICE