What was found
LEAVING FL410 FOR FL390, CAUTION MSG IAS DISAGREE WAS DISPLAYED ALONG WITH L & R ENG EEC, AILERON LOCKOUT APPEARED, & RUDDER RATIO. F/O A/S INDICATION DECREASED AS WE DESCENDED, AND PASSING FL250, THE F/O A/S INDICATION RETURNED TO NORMAL.(<P>PERFORMED PITOT HEAT TEST IAW AMM 30-31-00, NO DEFECTS NOTED. PERFORMED F/O'S PITOT SYSTEM LEAK TEST IAW AMM 34-11-00, NO DEFECTS NOTED. REMOVED AND REPLACED RIGHT ADC IAW AMM 34-12-01, OPS CHECK GOOD.<BR /></P>)