What was found
(CAN) ON TAKEOFF AT 70 KNOTS, CREW OBSERVED AN IAS INDICATED AIRSPEED DISAGREE MESSAGE ON BOTH PRIMARY FLIGHT DISPLAYS. TAKEOFF WAS ABANDONED. MAINTENANCE PERFORMED FIM 31-62, TASK 876. FOUND RT, F/O PITOT SYS SLOW TO RESPOND AND LAGGING BY 4-6 KNOTS AT ALL SPEEDS. PERFORMED RT PITOT SYS FLUSH AND TESTED PITOT SYSTEMS SERVICEABLE IAW AMM 34-11-00. AIRSPEED SPLIT LESS THAN 2 KNOTS. RAN BOTH ENGINES AND HAD NO ANOMALIES. NO HISTORY OF PROBLEMS WITH THE SYS. ACFT WAS RELEASED FOR SERVICE AND NO FURTHER ISSUE REPORTED.