I suspect it is more to do with making them "aviation grade" rather than anything else. I also suspect that it would require a lot more than 20amps to deice an airframe especically when can be looking at outside tems in the -40c region.
Despite a lack of icing systems there are not many days that actually cause icing problems. A guy in the US teaches the FA IR year round in a non iced single and has never had to cancel yet and his courses go al the way to alaska. a lot of the IR training organisations in the UK do not have de-ice. The twins I did my JAA IR in were de-iced and I never used them in anger. In fact I have only used the de-ice on the senecca once after spending an hour in the icing layer after not getting my filed level. I could have insisted on the climb or taken a descent but the ice was not bad and I wanted to test the systems.
Most of the time it is easy to climb on top of the icing layer and once clear of it the ice will melt quickly. In the winter the ice layer is low but then so are the cloud tops. In the summer it is the other way around and it is easy enough to fly above the cloud or below the freezing layer but above the MSA. Most performance singles will punch through it very quickly.
I get more worried about CB's than ice.
Last edited by S-Works; 23rd October 2006 at 10:43.