I checked my email today and Bird Tricks sent me this post, "How we teach parrots to fly outside". I have seen so many posts about how easy it is to free fly your bird and so many are pictured where there are NO trees, not even a bush and it's a no brainer that your bird is going to land on the highest thing around!
I have a hard time with this kind of training. I'm no professional but in my experience your bird better be bonded to you, if not, you are taking a bigger chance, a huge risk of losing your bird. I agree with recall training, to me it means a bonding experience and that is safer than anything, in my opinion.