Cozy MK IV

Cozy MK IV
Cozy MK IV
Role	Homebuilt aircraft
National origin	United States
Manufacturer	Home Built
Designer	Nat Puffer
Primary user	Private
Developed from	Rutan Long-EZ

The Cozy Mark IV is a 4-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. It is a derivative of that aircraft, designed with approval from Burt Rutan. The Cozy Mark IV 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.

Construction

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. RA7715 fiberglass is almost entirely unidirectional in its fiber orientation. RA7725 has an equal portion of perpendicular fiberglass strands. Epoxy systems used include EZ-Poxy, Safe-T-Poxy, MGS L285 and L335, and West Systems. 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 several suppliers exist for these parts.

Previous Versions and Related Aircraft

Like the Long-EZ, the design includes a retractable nose gear and fixed main gear. With both front seats unoccupied, the center of gravity with the aircraft level is aft of the main gear. Thus, like the Long-EZ, the Cozy is parked with the nose resting on the ground, sometimes called "grazing". The nose-down position is very stable. The aircraft can withstand high winds as the wings are beyond a flying angle of attack. Some Cozy builders modify the design to include retractable main gear. This modification increases the maximum speed by a few knots. Maximum fuel tank capacity is reduced to accommodate the retracted gear.

The Cozy III was a 3-seat aircraft and the predecessor of the 4-seat Cozy Mark IV. Also designed by Nat Puffer, the Cozy III was initially referred to as simply "The Cozy". When the 4-place was announced, the qualification of the Cozy III name was required.

The Cosy Classic is the European version of Cozy III, changed to a forward opening canopy and other modifications. The forward opening canopy design is available from Uli Wolter, the designer of the Cosy Classic modifications.

Engine Types

The plans call for a Lycoming O-360 engine (180 hp) or O-320 (150-160 HP). There are Cozys flying with several different engine types:

• Lycoming IO-360,
• Superior Air Parts and ECI O-360 clones
• Mazda 13B rotary
• Subaru 2.5 and 3.3
• T-58 turbine (one example, "The Cozy Jet")

Specifications (Cozy MK IV)

^[1] General characteristics

• Crew: one
• Capacity: three passengers
• Length: 16 ft 10.8 in (5.151 m)
• Wingspan: 28 ft 1.2 in (8.565 m)
• Height: 7 ft 10.8 in (2.408 m)
• Wing area: 88.3 sq ft (8.20 m²)
• Empty weight: 1,050 lb (476 kg)
• Gross weight: 2,050 lb (930 kg)
• Powerplant: 1 × Lycoming O-360 , 180 hp (130 kW)
• Propellers: 2-bladed

Performance

• Cruise speed: 190 kn; 350 km/h (220 mph) @ 75% power
• Range: 1,000 nmi (1,200 mi; 1,900 km) At 75% power
• Service ceiling: 20,000 ft (6,100 m)
• Rate of climb: ²⁰⁰⁰⁄₁₂₀₀ ft/min (0.00847 m/s) Solo/Gross

See also

• Rutan Long-EZ
• Rutan VariEze
• Rutan Defiant
• Berkut aircraft
• Velocity SE
• Velocity XL
• Steve Wright Stagger-Ez
• Canard
• Pusher configuration

External links

• Cozy Aircraft Company
• The unofficial Cozy builders web site
• Canard aviation forum
• Canard zone forums
• Canard builders forum
• EzJet
• The Canard Aviation Wiki
• RJ.03 IBIS Canard
• Aircraft spruce - Cozy Mark IV plans
• AeroCad - the kit version of the Cozy Mark IV
• Wicks Aircraft Supply - Cozy Kit components

1. ^ . Cozy Aircraft Official Website. Aug 19th, 2011 http://www.cozyaircraft.com/