If you are proficient at landing you can go 6 inches, thats where I found the plane to fly 3D best for me and still be manageable for landing. If you still struggle with landings I would say no more than 5" or so. Mine was a little tricky to land at 6". It wanted to approach nose high and pretty much landed from a harrier position. I have heard as far back as 7" but I personally wouldnt go that far back.