Citation Excel (C560XL)
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Situational Awareness; Troubleshooting
Aircraft Equipment Problem Less Severe; Inflight Event / Encounter Weather / Turbulence
Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Overcame Equipment Problem; General Maintenance Action
Aircraft; Weather
At FL370; we were about 20 minutes from ZZZ; we noticed we had a mis-compare between the ADC 1 and 2 readout. We notified ATC about the problem and requested a descent to find warmer air suspecting we had freezing moisture in our static lines. We worked with ATC the whole way into ZZZ advising them of our misleading altitudes and speeds. We crossed traffic and received a traffic advisory but not an RA. ATC did not mention any issues. We landed and had mx look at the static system. The problem was a large amount of moisture in the static lines. We are working with maintenance to find a static port cover for the plane. We've also mentioned to the plane owner that we could start hangaring the plane to reduce this chances of this problem again.
A Cessna Citation Excel Captain reported an anomaly with the pitot static system; suspected to be due to icing; which affected the air data computers.