The above discussions about ice on aircraft from the various respondents , shows a basic misunderstanding about the problem. The previous accidents were all about take off related icing problems...ie ice forming on the aircraft while on the ground and then being ingested by the engines after take off. This is guarded against by de-icing before take off and observing hold over times relevent to the weather conditions. The F 70 being an aircraft with a super critical wing (No leading edge devices too) the hold over times and a clean wing BEFORE take off is vital.
This accident today though was not during this phase of flight , and in no way related to these type of problems. The F70 de-ice / anti ice systems work perfectly well in all ice conditions that I've encountered...as long as they are turned on and operating normally.