The Rutan VariEze is a
composite
Composite or compositing may refer to:
Materials
* Composite material, a material that is made from several different substances
** Metal matrix composite, composed of metal and other parts
** Cermet, a composite of ceramic and metallic materials
...
,
canard aircraft designed by
Burt Rutan
Elbert Leander "Burt" Rutan (; born June 17, 1943) is a retired American aerospace engineer and entrepreneur noted for his originality in designing light, strong, unusual-looking, and energy-efficient air and space craft. He designed the recor ...
. It is a high-performance
homebuilt aircraft
Homebuilt aircraft, also known as amateur-built aircraft or kit planes, are constructed by persons for whom this is not a professional activity. These aircraft may be constructed from "scratch", from plans, or from assembly kits.Armstrong, Kenn ...
, hundreds of which have been constructed. The design later evolved into the
Long-EZ
The Rutan Model 61 Long-EZ is a tandem 2-seater homebuilt aircraft designed by Burt Rutan's Rutan Aircraft Factory. The Long-EZ has a canard layout, a swept wing with wingtip rudders, and a pusher engine and propeller. The tricycle landing g ...
and other, larger cabin canard aircraft. The VariEze is notable for popularizing the canard configuration and moldless
glass cloth
Glass cloth is a textile material woven from fiberglass yarn.
Home and garden
Glass cloth was originally developed to be used in greenhouse paneling, allowing sunlight's ultraviolet rays to be filtered out, while still allowing visible light thr ...
composite construction for homebuilt aircraft.
Overview
Work on the VariEze design, which grew out of Rutan's experience designing and building the
VariViggen, began in 1974. The first prototype, designated Model 31 and registered N7EZ, first flew on May 21, 1975 after four months of construction. This aircraft used a
Volkswagen engine conversion. Three months later it was shown at
Oshkosh where
Dick Rutan
Richard Glenn Rutan (born July 1, 1938) is a retired United States Air Force officer and fighter pilot, test pilot, and record-breaking aviator who in 1986 piloted the Voyager aircraft on the first non-stop, non-refueled around-the-world flight w ...
piloted it to an under 500 kg class distance record of . Rutan believed that by engaging in a program of breaking class records he could further fine-tune the design.
The aircraft was so popular at Oshkosh that Rutan redesigned the aircraft so that it could be sold as a set of plans. A second prototype, the Model 33, N4EZ, built using a larger wing, a
Continental O-200
The Continental C90 and O-200 are a family of air-cooled, horizontally opposed, four-cylinder, direct-drive aircraft engines of 201 in³ (3.29 L) displacement, producing between 90 and 100 horsepower (67 and 75 kW).''Federal Aviation Admini ...
engine, and many other detail changes, was shown at Oshkosh in July 1976 and plans were offered for sale. Approximately 2000 aircraft were under construction by 1980, with about 300 flying by late 1980. Ultimately more VariEzes and Long-EZs (a derivative, slightly larger design) were constructed than any other homebuilt type of the time. The sale of plans ceased in 1985.
Rutan's stated goals for the design included reduced susceptibility to
departure/spin and efficient long range cruise; these goals were achieved. The use of a canard configuration allowed a stall-resistant design, at the price of somewhat increased takeoff and landing speeds and distances relative to a similar conventional design with effective
flaps. The holder of the
CAFE
A coffeehouse, coffee shop, or café is an establishment that primarily serves coffee of various types, notably espresso, latte, and cappuccino. Some coffeehouses may serve cold drinks, such as iced coffee and iced tea, as well as other non-caf ...
Challenge aircraft efficiency prize briefly was Gary Hertzler, set using a VariEze.
The prototypes flew originally with
elevons
Elevons or tailerons are aircraft control surfaces that combine the functions of the elevator (used for pitch control) and the aileron (used for roll control), hence the name. They are frequently used on tailless aircraft such as flying wings. A ...
on the canard for both
pitch and
roll
Roll or Rolls may refer to:
Movement about the longitudinal axis
* Roll angle (or roll rotation), one of the 3 angular degrees of freedom of any stiff body (for example a vehicle), describing motion about the longitudinal axis
** Roll (aviation), ...
control but the design was changed to pitch control with the canard elevators and roll control with mid span wing
ailerons
An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in Flight dynamics, roll (or ...
after a few aircraft were built.
While the airplane was resistant to pitch
departures, a few builders discovered a potential for a novel lateral departure mode resulting from one winglet stalling at large
sideslip angle
A slip is an aerodynamic state where an aircraft is moving ''somewhat'' sideways as well as forward relative to the oncoming airflow or relative wind. In other words, for a conventional aircraft, the nose will be pointing in the opposite directio ...
s. An outer wing leading edge droop (and later
vortilon
Vortilons are fixed aerodynamic devices on aircraft wings used to improve handling at low speeds.
The vortilon was invented by aerodynamicists working at Douglas Aircraft who had previously developed the engine pylons for the Douglas DC-8. The or ...
s on some examples) was added to alleviate this problem and rudder travel was reduced.
The design's stall resistance did not appear to translate to a lower accident rate than for other homebuilts; a review of the NTSB database from 1976 to 2005 shows 130 total accidents and 46 fatal accidents out of a fleet of about 800 (691 registered in 2005). Precise comparisons are difficult, however, because of the haphazard nature of data collection and analysis for accidents involving homebuilt airplanes.
The VariEze is subject to a 2.5g positive, 1.5g negative, maximum load factor limit applied after the discovery of problems with some VariEze wings.
[.]
In lieu of a parking brake, the
nosewheel retracts and the nose rests on the ground. Referred to as kneeling, this eases access to the cockpit. Resting the nose on the ground also prevents the plane from tipping onto its rear when the pilot's seat is unoccupied.
Specifications
See also
Notes
References
* "Flying the VariEze", ''Air Progress'', April 1978.
National Air and Space Museum VariEze history
National Air and Space Museum VariEze Kit Components
*
Taylor, John W. R. ''Jane's All The World's Aircraft 1982–83''. London:Jane's Yearbooks, 1982. .
Getting 45 MPG at 207 MPH''Flight International'' 1976
External links
{{Scaled Composites
1970s United States sport aircraft
Canard aircraft
Homebuilt aircraft
VariEze
The Rutan VariEze is a composite, canard aircraft designed by Burt Rutan. It is a high-performance homebuilt aircraft, hundreds of which have been constructed. The design later evolved into the Long-EZ and other, larger cabin canard aircraft ...
Mid-wing aircraft
Single-engined pusher aircraft
Aircraft first flown in 1975