symmetrical airfoil. S-1S Aerotek-built certified S-1C for competition aerobatics, round airfoil section, four ailerons, and powered by a 180 hp (134 kW) Lycoming AEIO-360-B4A; 61 built. This model is also available from Aviat Aircraft as a plans-built aircraft. S-1SS Similar to the certified S-1S "Roundwing". 180–200+ hp (134–149 kW), single-seat, homebuilt, symmetrical wing, four symmetrical "Super-Stinker" style ailerons, 300 degree/s roll rate, fixed-pitch propeller. This model is available in plans and components form from Steen Aero Lab. S-1T Aerotek-built S-1C with a 200 hp (149 kW) Lycoming AEIO-360-A1E and minor changes; 64 built. Four-aileron, single-seat, factory-built, symmetrical wing, symmetrical ailerons, constant speed two- or three-blade Hartzell propeller. The top wing was moved forward compared to the S-1S for weight and balance. This model was in production in 2008 from Aviat Aircraft as an "on-demand" manufacture product. S-1-11B Known as Model 11 "Super Stinker", 300+ hp (220 kW) Lycoming, four-aileron, single-seat, experimental-plans or factory-built and factory component parts, symmetrical airfoil, three-blade constant speed prop, rolls better than 300 degree/s, climbs better than 3,000 ft/min (15.3 m/s). S-2 Scaled up S-1 with tandem two-seat fuselage and powered by a 200 hp (149 kW) Lycoming AEIO-360-B4A piston engine. S-2A Aerotek-built S-2A with a 200 hp (149 kW) Lycoming AEIO-360-A1A or -A1E piston engine, constant speed propeller, later builds have a longer landing gear and a front cockpit; 259 built. S-2B Aerotek-built S-2A with a 260 hp (194 kW) Lycoming AEIO-540-D4A5 engine, upper wing auxiliary fuel tank, the landing gear and upper wings were moved forward six inches; 196 built. The aircraft is out of production but is supported by Aviat Aircraft. S-2C Four aileron, two-seat, factory-built, symmetric airfoil, 260 hp (194 kW) Lycoming driving constant speed three-blade propeller, current production model. This was an evolution of the S-2B model, with improved ailerons and rudder, flat bottom fuselage, lower profile bungee gear, better inverted handling, and certified for +6 -5g. It is in production in 2008 by Aviat Aircraft. S-2E Amateur-built S-2A from factory-produced kits. S-2S Aerotek-built S-2B with a single cockpit and a twin tank fuel system. The fuselage is shortened by 14 inches (35 cm) forward of the cockpit to allow the installation of the heavier 260 hp (194 kW) Lycoming AEIO-540-D4A5. The wingspan is 20 ft, 0 inches (6.10 m); 17 built. This model is currently out of production, but supported by Aviat Aircraft. S-2SE Amateur-built S-2S from factory-produced kits. Operators