What was found
DURING TAKE OFF, IMMEDIATELY AFTER SETTING POWER, CAPTAIN`S AIRSPEED AND ALTIMETER STARTED FLUCTUATING. RUDDER RATIO ANNUNCIATED IN EICAS AND OVERHEAD. REJECT AIRSPEED WAS ESTIMATED AT 100KTNS ON FIRST OFFICER'S INDICATOR. TROUBLESHOT IAW FIM 34-12-00-1, LT AIR DATA COMPUTER REPLACED IAW AMM 34-12-01-4. MCDP TEST 30 PERFORMED IAW AMM 22-00-02-2, NO FAULTS PRESENT. AIR DATA COMPUTING SYSTEM OPERATIONAL TEST PERFORMED IAW AMM 34-12-00-5.