the series, the Sikorsky S-434, was released in 2008. Helicopter products offered by the company in February 2009 included the 300C, 300CBi, and 333. In 2011 and 2012 Sikorsky Aircraft Corporation laid off all the workers and closed the plant. After the sale of the company, helicopter production was restarted in Fort Worth, Texas in 2018. Sailplanes Schweizer is known for its popular line of gliders (sailplanes), the earliest of which (the model SGP 1-1) was produced in 1930. Although very few of the early gliders were built, later models gained popularity, such as the SGS 2-8 and 2-12, which were adopted by the U.S. Army Air Corps for training as the TG-2 and TG-3, respectively. The Schweizer SGS 1-23 was a world class competition and record setting glider between its first flight in 1948 and the end of its production in 1967. In the 1950s and 1960s the Schweizer Aircraft Corporation designed and manufactured the very popular SGS 1-26 and SGS 2-33 gliders. In the 1970s the single place SGS 1-34 (and 1-34R retractable gear version) was introduced. They are easy to fly, with simple construction, and are quite rugged and forgiving. Later in the 1970s and 1980s the higher performance t-tail SGS 1-35 and SGS 1-36 Sprite were introduced. A powered light aircraft, the Schweizer SA 1-30 was tested, but did not go into production. The 2-33 was adopted by the United States Air Force Academy as the TG-4, for use in introductory airmanship training. The Academy used over a dozen such gliders until 2002 when they were replaced by more modern sailplanes. The Royal Canadian Air Cadets continue to operate a fleet of over seventy 2-33As. The popular Schweizer gliders the single-seat SGS 1-26, the two-seat 2-33, and the two or three-seat SGS 2-32 can still be found at many gliding clubs across the U.S. Ag Cat Schweizer produced the Grumman G-164 Ag Cat, a single-engine biplane agricultural aircraft originally developed by Grumman in the 1950s. Under the contract with Grumman the airplane was built almost continuously between 1957 and 1981. During this period of time Schweizer built 2,455 of the airplanes. In 1981 Schweizer bought the rights to the design and continued production under the name Schweizer Ag Cat. In 1995 Schweizer sold the rights to the Ag Cat to Ag-Cat Corp. of Malden, Texas. In February 2001 the design was sold to Allied Ag-Cat Productions