I've got the 40 size... do a search on it... lots of good threads...I acctually flew mine for the first time today and it's a sweet plane. The YS .63 gives it Unlimited vertical , and it's still has less than a gallon of fuel thru it, and I fly at 5000 ft ASL.... So amazingly light, well constucted and great flyer. Do the search and you'll get the skinny on it