Living in Cannington, i daily watch the incoming jumbo jets fly low over my house preparing to land.
Funny i have not yet seen any trail EVER from one of these planes.
Of course,the atmosphere or something in Perth is never conducive for the formation of these trails

In the UK, as the aluminium/assorted trails spread out, it blocks the passage of sunshine,can't have the Poms getting their daily intake of vitamin D now can we