Originally Posted by
BobM2
As for tail icing, the trimmable tailplane seems to eliminate this as a problem.
What has eliminated tailplane icing as a safety hazard is not a specific design feature (such as trimmable tail) but rather industry acknowledgment of the risk, and designing for it, and having to certify for it.
As mentioned somewhere higher up, many types do not have tailplane anti-ice or de-ice, but have had to demonstrate, during certification, freedom from hazardous characteristics with significant ice accumulation on the tail - up to 3" of ice is the norm for most requirements. If your design can't hack it with three inches of ice, then you aren't going to get certified today, so your only choice then becomes to add something to prevent that ice forming.