The Cozy III is a 3-seat, single engine, homebuilt light aircraft designed by Nat Puffer. The aircraft is built from plans using basic raw materials. It is not a kit aircraft, though many small parts are available prefabricated. The Cozy is similar in design and construction to the 2-seat Rutan Long-EZ, from which it is derived, with approval from Burt Rutan.
The Cozy utilizes foam and fiberglass sandwich construction, with foam suited to the usage, fiberglass oriented for the stresses, and epoxy to bond them together.
Nat Puffer designed the aircraft as a high speed cross-country VFR aircraft, although many builders equip their planes with IFR capabilities.
The aircraft is constructed primarily of fiberglass, foam, and epoxy. Urethane foam is used to form highly curved, hand-carved shapes such as the nose and wing tips. Blue rigid styrofoam is cut with a hot wire saw to form the wing cores. Thin PVC foam sheets are used to form bulkheads and the fuselage sides. Two types of woven fiberglass are used to provide the surface strength of the composite sandwich. The builder does not need pre-fabricated items to finish the aircraft except for the landing gear bow and nose gear strut which require forms and an oven for post curing, but suppliers exist for these parts, such as Featherlite of Ukiah CA.
The recommended engine is the 1200NaN0 Lycoming O-235, but a variety of powerplants from 160to have been used.
http://stargazer2006.online.fr/derivatives/pages/cosy.htm
http://www.airventuremuseum.org/collection/aircraft/5Puffer%20Cozy%20CO-Z.asp