Viking SF-2A Cygnet
The Viking SF-2A Cygnet, also called the Sisler SF-2A Cygnet and the HAPI SF-2A Cygnet, is an American STOL amateur-built aircraft, designed by Bert Sisler and produced by Viking Aircraft LLC. The aircraft is supplied in the form of plans for amateur construction. The Cygnet first flew in 1973.
The Cygnet plans were originally marketed by the designer through his company Sisler Aircraft of Bloomington, Minnesota and later by HAPI Engines, a supplier of Volkswagen air-cooled engines. By the 1990s Viking Aircraft of Elkhorn, Wisconsin took over supplying the aircraft plans.Design and development
The SF-2A Cygnet is a development of the earlier Sisler SF-2 Whistler introduced in 1973. The design features a strut-braced shoulder-wing, a two-seats-in-side-by-side configuration enclosed cockpit under a bubble canopy, fixed conventional landing gear and a single engine in tractor configuration.
The aircraft is made from wood, 4130 steel tubing and covered in doped aircraft fabric. Its span wing employs a NACA 3413 airfoil, has an area of and is supported by a single strut with a jury strut. The cockpit is wide and has a baggage compartment with a limit of, located behind the seats. The aircraft's recommended engine power range is and standard engines used include the Volkswagen four-stroke powerplant. Construction time from the supplied kit is estimated as 1700–1800 hours.
The Cygnet won a design award at the EAA Annual Convention and Fly-In in 1973.Operational history
By January 2003, 100 examples had been reported as completed and flown.
In July 2016 a total of 19 SF-2A Cygnets were registered in the United States with the Federal Aviation Administration, four with Transport Canada and seven with the Civil Aviation Authority in the United Kingdom.Specifications (SF-2A Cygnet)
