Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Aircraft Equipment Problem Critical; Deviation - Speed All Types; Inflight Event / Encounter Weather / Turbulence
Flight Crew Overcame Equipment Problem
Weather; Aircraft
While on our flight from ZZZ to ZZZ1; ATC (Air Traffic Control) advised us of an area of weather about 100 miles in front of us. We were advised to let them know if we wanted to deviate. The weather radar was used to scan the area of concern. Once within approximately 50 miles of the weather; we decided it would be best to deviate to the right/north. ATC gave us permission to deviate as much as needed; which we turned approximately 25 degrees towards the north. We were also given a discretionary descent down to FL240; as we were still at cruise altitude and about 120 miles from ZZZ1. We identified an area of weather that was giving a very weak return; along with a large gap. We turned towards ZZZ1 to utilize the gap in weather; which kept us around 30 miles north of the main area of concern (strong radar returns). We were IMC (Instrument Meteorological Conditions) at this time with light turbulence; and I elected to pull the speed back to 220kias. I then noticed an IAS (Indicated Airspeed) flag followed shortly by ALT and a CAS message. It was at this point we realized we had encountered high altitude icing and unreliable airspeed. Although my side seemed to be accurate; the First Officer side airspeed indicator was reading well below normal; before dropping off completely. We notified ATC; and began our discretionary descent. The appropriate QRH (Quick Reference Handbook) procedure was followed and we descended normally into ZZZ1. Once in the clear and at lower altitudes; the first officers PFD (Primary Flight Display) began giving normal indications again. The major threat was unreliable airspeed; while in IMC; at altitude. Per the QRH procedure; the aircraft was hand flown with no auto pilot; flight director; or yaw damper. While descending to FL240 we were given a further descent to 11;000. Correct and normal indications returned before reaching 11;000; and a normal approach was flown into ZZZ1.We both felt that the sim training we recently received on this was tremendously accurate. The aircraft indications along with the pace of deterioration was exactly like the sim scenario training we had done. We already knew which QRH procedure to find and utilize; which worked well.
Flight Crew reported erroneous Airspeed Indicator readings due to icing.