28 degrees, thick fog, right at sunrise, I was hoping to get some spectacular shots and video breaking above the fog. Flew low at first then ascended considerably to try to get above the fog. No break in sight so time to come down. Descending, my P3P seemed a little louder than normal. As I finally got it to about 300' and stopped when I saw it, it started to yaw. Obviously gave my heart a race thinking it would crash or take off. It did it 2 or 3 times when I would stop the descent. Scary! The good news is that I was right over head. As I descended slowly, I did a hand catch as always and then noticed the icing on all 4 props! No wonder it was acting weird! In almost 2yrs of flying Phantoms, even in sub zero temps, this is the first time I have "iced." Just another experience, I'm glad I got a good landing out of.