What was found
ON DECENT IN IMC CONDITIONS, FIRST OFFICER'S IAS BECAME INVALID, DROPPING TO APPROX 140 KTS, CAPTAIN'S & STBY WERE NORMAL. AFTER FURTHER DECENT FIRST OFFICER'S IAS STARED WORKING NORMALLY & CAPTAIN'S IAS BECAME UNRELIABLE DROPPING TO APPROX THE BOTTOM OF THE SCALE. AFTER A FEW MINUTES & FURTHER DECENT ALL IAS INDICATIONS RETURNED TO NORMAL. DRAINED FAIR AMOUNT WATER FROM CAPTAIN`S SIDE, LOTS OF WATER FROM FIRST OFFICER`S SIDE VIA QUICK DISCONNECTS. DID DUAL PITOT STATIC SYS LEAK CHECKS IAW AMM 34-13-00, ALL CHECKS WERE GOOD. BOTH ADC'S OPS CHECKED GOOD IAW 34-15-00. BOTH ADC'S & PITOT STATIC SYS ARE RVSM ELIGIBLE .