What was found
IAS DISAGREE EICAS AT CRUISE. QRH ACCOMPLISHED DETERMINED RIGHT SIDE INCORRECTCREW REPORTS F/O AIRSPEED FLUCTUATES FROM 6-20 KNOTS DIFFERENCE FROM CAPTAIN , STANDBY INST AIRSPEED AGREES WITH CAPTAIN , WHEN F/O SWITCHES TO ALTN AIR DATA , INFO IS CORRECT AND CAPT AND F/O AIRSPEEDS MATCH, SUSPECT F/O PITOT HEAT INOP LEADING TO CLOGGED TUBE, OR AIRDATA MODULE FAIL , OR POSSIBLE SYSTEM LEAK PERFORMED FLUSH OF THE FO PITOT SYSTEM IAW AMM 34-11-00-173-009. SMALL AMOUNT OF DEBRIS CAME OUT OF THE SYSTEM. WILL REQUIRE LEAK CHECK IAW AMM TASK 34-11-00-795-180 DUE TO THE DRAIN LINE BEING DISCONNECTED AND RECONNECTED DUE TO THE FLUSH. QD FOR FO PITOT ADM RECONNECTED. PERFORMED PITOT/STATIC PROBE HEATER RESISTANCE CHECK IAW TASK 30-31-00-200-807 RESISTANCE OF FO PITOT HEATER WITHIN LIMITS. CONFIGURED CAPT AND FO PITOT SYSTEMS FOR LEAK TEST UP TO STEP G. OF IAW AMM TASK 34-11-00-795-180. WHEN TESTING FO SIDE (PER STEP. I) IN ISOLATION VIA THE MANIFOLD, LEAK RATE IS WITHIN ACCEPTABLE LIMITS & AIRSPEED IS APPROX 5 KNOTS BELOW THE TARGET. WHEN TESTING IT IN CONJUNCTION WITH THE CAPT SIDE BOTH AIRSPEEDS ARE 12 KNOTS BELOW TARGET. CAPT SIDE IN ISOLATION SHOWS AN EXCESSIVE LEAK. FURTHER T/S REQUIRED TO RULE OUT THAT THERE IS A LEAK ON THE CAPT SIDE. CONFIRMED NO LEAKS IN CAPT'S AND FO'S PITOT SYSTEM. BOTH CAPT'S AND FO'S AIRSPEED AGREE. ACCURACY AND LEAK CHECKS LEAK CHECKS GOOD REF MM34-11-00-795-180. PREVIOUS UPDATE REFERRES TO LEAK IN CAPT'S PITOTNOTICED.