Another question, at 500 feet, were you loosing control or would it just not fly any further out?
I think 500 feet is the default geo fence. So yes the aircraft will go that far and stop if you are in SMART MODE.
In ANGLE MODE (Purple/White flashing tail light), She will do a bit better than a mile, but you will lose line of site long before that.
I usually stay 1500 feet or less away, just don't care to squint to see it.
As Eagle suggested, fly in Angle mode as much as possible. SMART MODE is also very unsafe to take off in. If you are too close, on lift off the aircraft can suddenly and very quickly fly up and away from you if it thinks you are to close. Several people have had their's crash into trees, houses, and cars because of this.
I only use Smart mode when I want to use the Watch me/Follow me modes.