Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Human-Machine Interface
Aircraft Equipment Problem Critical; Inflight Event / Encounter Weather / Turbulence
Aircraft Equipment Problem Dissipated; General Declared Emergency
Weather; Aircraft
The First Officer was flying at FL360 in IMC when we got an IAS speed flag and noticed my side had a discrepency. We referenced the QRH; selected ADC1 and descended to FL240 to get out of RVSM airspace. While descending the First Officer's airspeed bled off; so we deemed unreliable and used the standby airspeed indicator. We declared an emergency and contacted the company for alternates but all suitable airports had low visibilities and ceilings. Once at FL240; however; all airspeed indicators began to match up with the standby. We reviewed all weather options and decided to continue to our destination because weather was improving and I felt it was a safe and practical decision.I felt we worked very well together. I invited his thoughts and opinions on what was going on so that I would have not just my own view but would get someone elses take as well. I felt our teamwork produced the safest and most practical decision making for the scenario.
When their airspeed indicators became unusable due to frozen moisture in the pitot system lines the flight crew of an EMB-145 descended out of IMC and below RVSM airspace where the blockage dissipated and they were able to continue to their destination.