Nodd, that is a copy of the Polaris which is a great airplane. I have built 2 polaris so far, one is heavy and one is light. You want to keep it light. It flys soooooo much better light. The most we usually put on the bottom of our Polaris is clear duct tape, and only from the step forward. It is durable and does not add much weight. On my light one I have only put colored packing tape on it and I really enjoy flying the light one compaired to the heavy one. It has held up quite nicely and I fly off grass alot. Don't get me wrong, a heavy Polaris will still fly well, the design is just that way, it just won't fly great. If you want some reading information on this type of airplane, look up the Polaris thread over on RCGroups.com. The designer of the model started the thread with a free design for the do it yourselfer, later a company got the rights to make a kit of the plans and then designed an arf that was later copied by other countries. There are over 1500 pages and 23000 posts and thats not a typo. It is everything you need to know about that planform and all modifications that will make it fly well. You can even learn how to build one yourself if you want to save a few bucks over the hobbyking price.