Nat PUFFER / CO-Z DVPT. « COSY » (« COZY »)
(later known as 'Cosy Classic')




The prototype Cozy is now part of the EAA Museum collection.







The Cosy (or Cozy) can hardly disguise its Rutan Long-EZ origins.

Manufacturer:CO-Z Development (under Rutan license)

Type:  three-seater development of the Long-EZ

Powerplant: 1 x 118 hp Lycoming O-235-L2C (prototype)
                    1 x Lycoming IO-320 (typical)

Significant date: 1982

Nat Puffer was first hooked on the Rutan design when an article appeared in Popular Science on the Rutan VariEze. Nat Puffer loved everything about the VariEze he built in 1978, except the tandem seating arrangement. He wanted his wife, Shirley, beside him. After building his own VariEze, Nat heard of another VariEze kit for sale at a bargain price. Nat immediately bought the kit and hatched the idea of a side-by-side Long-EZ.

Itching to build a new canard composite aircraft in side-by-side configuration, Nat asked Burt Rutan if he had plans for another design. Though Nat was enthusiastic about modifications, Burt was wary of people modifying his designs. He told Nat about his then-current project, the Long-EZ. Nat liked what he heard but, against Burt’s advice, he redesigned the Long-EZ as a versatile three-seater. The Cozy prototype was powered by a 118 hp 0-235 L2C Lycoming engine. Its solid foam core composite design utilized a hot-wire saw construction technique and is the simplest, least expensive four-place design on the market. Like most modern canard homebuilts, it was designed to be “ stall resistant”.

Building the Cozy involved a major redesign that involved widening the fuselage to measure 38 inches at the shoulders. The wider fuselage required extra reinforcement, which was accomplished in part by adding a keel inside the entire length of the fuselage. In addition to providing extra stiffness, the keel also housed a duct for cabin heat and provided a raceway for wiring and control cables. All engine and flight controls were mounted in the center console and dual side sticks, rudder pedals, and brakes were installed to enable complete control of the airplane from either side without having to reach across the other person.

Shirley and Nat debuted the “side-by-side Long-EZ” prototype at Oshkosh ’82 to a welcoming crowd, including Burt. Powered with a Lycoming O-235-L2C, the craft boasted a cruise speed of 180 mph on 118-hp at 2800 rpm. With a large instrument panel, dual wrist-action control sticks, and a large rear bay for baggage, a third person, or both, the couple could fly their sport plane on cross-country adventures in cozy comfort. Nat did not originally intend to produce plans for the Cozy, but after the Cozy’s debut at Oshkosh, many people were requesting information and photographs.

In the wake of N22CZ's success, Burt Rutan, reassured about the quality of the Cozy design, agreed to provide Nat’s company, Co-Z Development of Mesa Arizona, with a license agreement to sell plans that use Rutan’s technology. This offered Nat and Shirley a new career, as they went to work developing plans and an information kit and answering individual letters, creating the Co-Z Development Corporation. He formed the Co-Z Development Corp., furthering design development through the Cozy Mark III and four-place Cozy Mark IV designs. Although most Cosy/Cozy homebuilts have gone for the suggested Lycoming IO-320 engine, quite a few aircraft have used an assortment of other, variously powered Lycomings such as the O-360-A1D or the O-290. Even the Continental O-200 has been used.

The Puffers donated the Cozy Serial #1 to EAA in 1994, and the pusher is now often seen parked nose-down at EAA AirVenture. Other aircraft types based on the Cozy are the Aeromet AURA optionally-piloted vehicle and the Cozyjet.


Population: 1 prototype [N22CZ]
                   about 200 homebuilts

Specs: vary greatly according to each builder's options

Crew/passengers: typically 3 (sometimes 2)

Main sources:
- EAA's AirVenture Museum
- EAA's Attic - article by Kathleen L. Witman