The Sonerai is a small, VW-powered homebuilt aircraft, designed by John Monnett. The Sonerai began to compete as a single seat mid-wing Formula-V racer class formed in 1972. The Sonerai soon evolved into a two-seat model called the Sonerai II. Later versions included a low wing Sonerai IIL, a tricycle gear Sonerai IILT and finally the stretched Sonerai IILS and IILTS. John Monnett came up with the name Sonerai from a combination of the wordsSonic and Cosmic-Ray Many Sonerais have been built and it remains a very popular design for people seeking a low-cost experimental aircraft with good speed and maneuverability. The airframe cost to build in 1974 was estimated at $2,500. The 2010 airframe cost is approximately $6,000 and the total cost is approximately $15,000 with the addition of hardware, instrumentation, engine and other required items. The time to build is between 800 and 1000 hours.
Design
The Sonerai I design and construction started in 1970 with the goal of a flying aircraft to be demonstrated at the 1971 EAA airshow. The aircraft was to meet the new Formula V rules. Inspired by the Spitfire, an elliptical tail profile was incorporated. Elliptical wingtips and a low-wing configuration were dropped, but a low-wing Sonerai II variant was released later. The Sonerai I was designed to use a direct drive 1,600cc VW engine and the Sonerai II was designed to use the 1700cc VW engine. The wings were designed to fold alongside the fuselage for towing without a trailer and compact storage. The Sonerai II was designed to be soloed from the rear seat. The aircraft is built around a fabric covered steel tube fuselage with all aluminum wings and a fiberglass cowl. The plans cost $50 and $57 in 1974. Great Plains Aircraft Supply Company held the rights to the Sonerai series of aircraft until 2015. Sonerai Works LLC purchased the rights to Sonerai plans and parts from Great Plains in 2015. In December 2019 the design was acquired by Sonex Aircraft. The aircraft is not available as a kit, and is built using plans, although some parts are available.
Brian Dempsey built a Sonerai I that set a world record. The C-1a/0 Speed over a straight 15/25 km course of 292.15 km/h on February 19, 1989. Dempsey's record stood for 20 years. Robin Austin of Australia built a Sonerai IIL with a 100 hp Rotax engine. The aircraft has set the following FAI records for C-1a/0.
