The Icing on the Cake Wing

When I was a kid I used to protest when the grownups would knock all the beautiful icicles off the building overhangs. They were so shiny and magical in their elaborately overlapping patterns. But the grownups said they were dangerous, because they could fall on someone and hurt them. Grudgingly I had to agree that I would not want a giant icicle to fall on me, but I still liked to look at them. To me, a frozen waterfall is one of the most beautiful things in nature. All that power crystallized for the winter.

I have to admit to secretly admiring airframe icing. It's like a tiger: deadly dangerous, yet exotically beautiful. John, Sam and Shawn have recently blogged on the dangers of ice. Shawn has a great picture of leading edge ice. (More icing porn, please Shawn.) So in the wake of learned, cautionary posts by some of my blogging colleagues, I have the audacity to say "but ooh, isn't it pretty?"

I think it's fascinating the way, despite the rush of air past the wing, that rime icing develops forward into elaborate shapes. If the departure airport was above freezing, during the climb the fuel is still warm and warms the wings around the fuel tanks, so that ice forms first on the areas between the tanks. During descent, the fuel has been chilled to the temperature of the cruising altitude, and ice forms where befoer there were gaps. I like to watch the ice patches shrink to nothing as we descend into warmer air.

I feel terribly guilty admitting this, as ice causes so many accidents. I almost deleted it instead of posting it. I know the effect of ice on performance, and respond promptly to icing conditions, but I can admire the sleek beauty of the tiger even as I chase it away from the village, can't I?