My drake flies over the four foot pasture fence occasionally. And at least several times a week he'll fly one giant arc around the lower part of the yard where the chicken/duck pens are: I'd say at least 50 feet long and as high as 8 feet up. (Though it is on a hill so the ground is dropping below him). I'm sure he could fly further if he had the inclination, but it's kind of the edge of the natural boundaries of my yard, with a shed and a tree line. He often does this if my Pekin drakes are harassing him, but sometimes I think he just feels like flying. He always starts walking back up as soon as he lands, never flying. He usually comes to me when I call him.
I've had him since he was a few days old, so he knows where home is and wants to stay. Free range time is generally supervised because I don't want to take chances with predators. All animal owners have to decide their acceptable balance of freedom vs security. My personal opinion is better safe than sorry and so my birds don't get as much exploring time/space. I had my female's wings trimmed when I got her at almost a year old. She learned where home is and doesn't stray far. She can fly up enough to get away from the naughty Pekin boys
