Since light aircraft are being used more and more frequently in the IFR environment, icing is becoming a greater operational problem. This paper reviews the icing problem for light aircraft. Design criteria and flight testing techniques are discussed. The discussion is limited to general aviation aircraft whose maximum takeoff gross weight is less than 6000 lb. Both theoretical and flight test data are reviewed.Data are included which describe the increase in instrument-rated pilots and IFR flying activity in recent years. Flight profiles of a typical light aircraft are compared with larger aircraft. Performance penalties due to ice accumulations are presented for light aircraft, based on flight test experience to date at the Commercial Aircraft Div. of Cessna Aircraft Co.