Text Box: The Formula-1 GT class combines easy to fly Formula-1 aircraft, with the reliable, user friendly, and affordable Zenoah GT-80.  The engine must remain stock, and contestants must use race-provided gas and propeller.  There are many F-1 aircraft kits available with prices beginning at $850. Text Box: About the USRA:  The Unlimited Scale Racing Association is the official rules body for the USRA World Championship series of Giant Scale Races.  It is committed to the development and growth of Giant Scale racing through increased safety, standardized rules and procedures, and fair and honest officiating.  Text Box: Big Racers = Big Fun!