What was found
AIRCRAFT 1802, ATB RETURNED TO ATL DUE TO LOSS OF CAPTAIN'S AIRSPEED INDICATION, (FO AIRSPEED NORMAL), AND EICAS MSGS: R ENG EEC MODE, L ENG EEC MODE, RUDDER RATIO, AILERON LOCKOUT APPEARED. CORRECTIVE ACTION: FOUND DIRT CLOGGED CAPTAIN'S UPPER LEFT PITOT PROBE AND REPLACED. LP 6931708