What was found
WHILE AT FC 360 IN ICING CONDITIONS WE RECEIVED IAS MSG ON BOTH PFD'S. IT APPEARED THAT THE CAPTAIN`S SIDE & STANDBY WERE IN AGREEMENT. WE CONCLUDED THE FIRST OFFICER'S SIDE WAS INACCURATE. AT ONE POINT DURING A DESCENT CAPTAIN`S SIDE SPEED INCREASED NORMALLY WHILE FIRST OFFICER`S SIDE DECREASED SPEEDS INDICATING AT THAT TIME. CA-245 KNOTS FO 219 KNOTS. FIRST OFFICER`S SPEED RETURNED TO NORMAL UPON EXITING ICING CONDITIONS & USING ALL MODE POSITION FOR THE ICE DETECTION OVERRIDE. WE ALSO SAW GPS 2 NOT NAV ON FMS SPS ADVANCE IN AMBER, NO BLUE SPS SPEEDS MSG. PERFORMED PITOT STATIC SERVICING, FOUND WATER IN TUBES. PERFORMED ADC OPERATIONAL TEST CHECKS OK IAW AMM 34-13-00 & 34-15-00. ACFT IS COMPLIANT FOR CAT II & RVSM OPERATIONS.