many homebuilt aircraft were built in the 1960s, earning the S-1 a reputation as an excellent aerobatic aircraft, Pitts worked on the design of a two-seat aerobatic trainer version, the S-2, which first flew in 1967 and gained its type certificate in 1971. Factory-built aircraft produced by the Aerotek company at Afton, Wyoming were joined in production by the single-seat S-1S in 1973. In 1972, the US Aerobatic Team won the World Championships flying only Pitts biplanes. In 1977 Curtis Pitts sold his interests in the Pitts S-1 & S-2 to Doyle Child. Child later sold the rights in 1981 to Frank Christensen, who continued production at the Afton plant under the guise of Christen Industries. The rights for homebuilt versions of the Pitts were sold in 1994 to Steen Aero Lab, with the Afton factory and production rights being transferred to Aviat. Curtis Pitts died in 2005 at age 89. At the time of his death, he was working with Steen on the prototype of the new Pitts Model 14, a brand new, two-seat biplane designed for unlimited aerobatics powered by the 400 horsepower Vedeneyev M14P radial engine. The rights to the Pitts name is currently owned by Aviat which also owns the similar model to the Pitts in the Christen Eagle. The current inverted flat spin world record is 98 set on March 20, 2016 by air show performer Spencer Suderman over Yuma, Arizona. Suderman flew the Sunbird S-1x, a Lycoming IO-540-powered experimental variant of the Pitts S1. The maneuver began from 24,500' over the Yuma Proving Grounds and was recovered at 2,000' AGL. The previous world record for the number of consecutive turns in a flat spin was 81 also set by Spencer Suderman on March 13, 2014 in a Pitts S-2B from 23,000 ft altitude over the Naval Air Facility El Centro. Variants S-1 Basic single-seat Pitts aerobatic biplane with a flat M6 aerofoil section and lower wing ailerons only, fitted with a variety of engines. Two were built, the first named Special and the second Li'l Stinker. S-1C Amateur-built S-1 single-seat aircraft, flat bottom wing with ailerons on lower wing only, designed for 100–180 hp (75–134 kW) engines. First flown in 1960, the S-1 is currently available as a plans-built aircraft from Steen Aero Lab. S-1D Amateur-built S-1C with ailerons on all four wings, generally similar to S-1S. S-1E Amateur-built S-1C using factory-produced kits. Uses