| VariEze | |
|---|---|
 | |
| General information | |
| Type | Homebuilt aircraft |
| National origin | United States of America |
| Manufacturer | Rutan Aircraft Factory (plans supplier) |
| Designer | |
| Number built | 400+ (1982)[1] |
| History | |
| First flight | May 21, 1975[1] |
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TheRutan VariEze is acomposite,canard aircraft designed byBurt Rutan. It is a high-performancehomebuilt aircraft, hundreds of which have been constructed. The design later evolved into theLong-EZ and other, larger cabin canard aircraft. The VariEze is notable for popularizing the canard configuration and moldlessglass cloth composite construction for homebuilt aircraft.
Work on the VariEze design, which grew out of Rutan's experience designing and building theVariViggen, 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 aVolkswagen engine conversion. Three months later it was shown atOshkosh whereDick Rutan piloted it.
The aircraft was so popular at Oshkosh that Rutan redesigned the aircraft so that it could be sold as a set of plans.[2] A second prototype, the Model 33, N4EZ, built using a larger wing, aContinental O-200 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 todeparture/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 effectiveflaps. The holder of theCAFE Challenge aircraft efficiency prize briefly was Gary Hertzler, set using a VariEze.[3]
The prototypes flew originally withelevons on the canard for bothpitch androll control but the design was changed to pitch control with the canard elevators and roll control with mid span wingailerons after a few aircraft were built.
While the airplane was resistant to pitchdepartures, a few builders discovered a potential for a novel lateral departure mode resulting from one winglet stalling at largesideslip angles. An outer wing leading edge droop (and latervortilons 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[4] 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.[5]
In lieu of a parking brake, thenosewheel 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.
Data fromJane's All The World's Aircraft 1982–83.[1]
General characteristics
Performance
Related development
Media related toRutan VariEze at Wikimedia Commons