744 wing icing
I noticed an odd looking thing a while back, when standing above the wing of a 744 that had just come in from a 1hr30 min sector. It had a fair layer of visible icing on the upper wing surface,but only betwee the two engines. in other words the wing inboard and outboard of the area between the engines was free of ice.
What could have caused this? something to do with the way the anti-ice system is positioned?