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. 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.[1][2][3] The aircraft is made from wood, 4130 steel tubing and covered in doped aircraft fabric. Its 30 ft (9.1 m) span wing employs a NACA 3413 airfoil, has an area of 125 sq ft (11.6 m2) and is supported by a single strut with a jury strut. The cockpit is 39 in (99 cm) wide and has a baggage compartment with a limit of 70 lb (32 kg), located behind the seats. The aircraft's recommended engine power range is 60 to 82 hp (45 to 61 kW) and standard engines used include the 82 hp (61 kW) 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.
