Actual I have noticed in recent years less contrails for whatever reason, I suspect improved engine technology with better fuel economy and less pollution. > One only needs look at films of B-17 bombers > flying at 20+ thousand feet during WWII to see that this is not a a new > phenomenon. > > Vic > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist