What was found
WHEN STARTING DESCENT FL380 BOTH PFD'S UNRELIABLE AIRSPEED. ISI APPEARED NORMAL. RAN QRH 13-10. UNRELIABLE AIRSPEED APPEARED WHILE IN IMC(IN THE CLOUDS). BOTH AIRSPEED INDICATORS ON PFD'S DISAPPEARED WITH IAS FLAGS. AT APPROX F240 OUT OF CLOUDS CA AISPEED ON PFD REAPPEARED AND FLAG DISSAPPEARED. A FEW MINUTES LATER FO AIRSPEED REAPPEARED. BOTH APPEARED NORMAL FOR REMAINER OF FLIGHT. UPON INITIAL INSPECTION, FOUND WATER IN P2 DRAIN COLLECTOR TUBE ON ADC 2. REF 983213-1 NWRC FOR T/S AND WORK PERFORMED. R+R ADC2 PER REF. 34-13-01-400-801. OPS CHECK GOOD NO DEFECTS NOTED AT THIS TIME. ADC P/N OFF/ON 822-0372-697 S/N OFF 2NJCT S/N ON 33HVJ. SEE AML 4155124-1 AND 4155124-2 FOR CATII AND RVSM RELEASE.