Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Less Severe
Aircraft Equipment Problem Dissipated; General Maintenance Action; General Declared Emergency
Aircraft
When given descent [from FL370] noticed airspeed indicators (all three) were giving false readings. SAT at this altitude was -49 degrees. We could hear airspeed increasing as descent began; but airspeed indicators were indicating decreasing speed. The indications decreased at the same rate on all three indicators (CA; FO and Stby). The Stby was the first to clear itself followed by the CA at approx FL290; then finally the FO at approx FL250. When noticed condition used AOM volume 1 and looked up unreliable airspeed charts for EMJ 145 idle descent. Before putting charts to use airspeed indications started to return to normal. Charts were kept handy and used to verify readings during remainder of descent. Declared an emergency with ATC. Continued descent to destination. Weather was VFR for landing. Landed runway 18 uneventfully and notified dispatch and maintenance.
[Report narrative contained no additional information.]
The flight crew of an EMB-145 suffered the temporary loss of all three airspeed indicators while at FL370.  During the subsequent descent all three returned to normal operation.