What was found
ON 2ND ATTEMPT OF TAKEOFF EN ROUTE, CAPTS AIRSPEED IND SLOW TO INCREASE & 35 TO 40 KTS BELOW FO`S IND, REJECTED AT 80 KTS. MX R & R NR 1 ADIRU IAW T/C & NR 1 ADM, OPS CHK GOOD. AGAIN REJECTED T/O FOR CAPTS AIRSPEED IND 35 TO 40 KTS BELOW FO`S IND. MX R & R CAPTS PITOT PROBE IAW AMM, R & R NR 1 ADM IAW AMM DUE TO POSSIBLE CONTAM, & R & R HOSE BETWEEN PITOT PROBE & ADM. PERFORMED AIR DATA ADJUSTMENT, LEAK CHK GOOD. TEST OF ADIRU CONFIRMED FAILURE OF UNIT, REPLACED GYRO. INCOMING TEST OF ADM, NO FAULT FOUND, CALIBRATED UNIT & RETURNED TO SERVICE. AIRBUS PERFORMED FAILURE ANALYSIS OF ADM, HOSE, & PITOT PROBE. FOUND NO DEFECTS, BUT PITOT PROBE FOUND BLOCKED BY FOD. BLOCKAGE SEVERE ENOUGH TO RESTRICT AIRFLOW.