I have built 4 runways in an old field. They are all about 200 feet long, and 25 feet wide. What I did was cut the grass to 1 3/4 inches for the the runways, and 2 3/4 inches for the rest of the fields. I roll the whole thing every time I cut the grass. That really helped flatten it out and make it smooth. (Used to be very rough old cow pasture). This is more than long enough to launch and recover my 2 .40 powered planes. The best part is the hedgerows and the trees at all the edges to make it so that you practice being precise when you line up to land. I made a fair copy of the field for Realflight G2, and you could download it from their website. Just look for Bingo Field. Practice moving the wind around, and change the places that you stand. That's how I practiced. The first picture is what it looked like before I started. The second picture is from about 2 weeks ago. I use painted milk jugs half filled with water so they don't blow around to mark the ends of the runways so I have an easier time lining up on them. Make sure you push them back as far as you can if you use this , I found out the hard way that striking one with the nose gear will rip a firewall right out of the fuselage.........