Persistent trails used to be much more rare than non-persistent ones but now the situation is reversed. I think either it's from some unknown fleet of high flying aircraft utilizing the "always persistent trails" area of the Appleman chart or it's aerosols. I am ok with not knowing the answer. Maybe the fruitcakes are the ones who think they know for sure like you.

Persistent trails used to be much more rare than non-persistent ones but now they are much more common. I think either it's from some unknown fleet of high flying aircraft utilizing the "always persistent trails" area of the Appleman chart or it's aerosols. I am ok with not knowing the answer. Maybe the fruitcakes are the ones who think they know for sure like you.