Descending wingtip vortex ?
In avoiding wake turbulence I've always been told the wing tip vortex spreads out and descends behind the airplane due to the fact that the vortex is using up its energy.
Does anybody know whether there's a formula or a rule of thumb to determine a safe distance behind a Heavy should you fly at a lower altitude?
A while ago I was flying right-seat in a Pa-28 with radar-vectors over Miami Int. when I spotted a Heavy at my 2o'clock.And about 2000' higher.
By the time we crossed behind it was about 5mi to our left.I was kinda worried about it but didn't do anything besides thinking of the question.
Anybody?