Tuesday, May 25, 2010
Evolution Of An Original
The Lycoming-powered Evolution turns in turboprop performance on a piston budget
The new Evolution was intended specifically for certification, so the airplane was designed to comply with all the standard parameters and flight tests required for Part 23 approval. The vision for the project came from Lancair owner and CEO Joe Bartels, who knew that standing by tradition means letting everyone else pass you by. Bartels knew his company needed a new product for the 21st century. The Lancair IV’s performance was spectacular, but that airplane was designed in the late 1980s. Bartels felt it was time for something new.
The Evolution is most emphatically “something new.” From spinner to tailcone, the design literally shouts speed and efficiency. The semicircular, swept, carbon-fiber fuselage also suggests pressurization, and that’s another important part of the design. This airplane specifically targets speed and comfort.
A 21st Century Design
By any measure, the Evolution’s carbon-fiber fuselage is an ecstatic shape, as smooth as Murano glass. The airplane looks like something Luke Skywalker would fly, full of consonant lines and completed ideas, like a good piece of music. The wing is a beautiful, quarter-elliptical design, an arcing, graceful planform unlike anything most pilots have seen before. In fact, it’s actually a combination of four distinct airfoils configured by aerodynamicist Greg Cole of Windward Aviation in Bend, Ore.
Cole’s credentials include a master’s degree in aerospace engineering from Notre Dame, plus design work at McCauley Propeller Systems, where prop designs nearly always incorporate multiple airfoils. In addition, Cole has participated in a variety of sailplane and other experimental aircraft projects. The engineer has been working with Lancair on development of everything from the two-seat Legacy to the Columbia 300/350 (back when the companies were combined—the airplane is now known as the Cessna Corvalis). Cole is considered especially adept at designing airfoils with low Reynolds numbers (read “laminar flow wings”).
Lancair General Manager Tim Ong was the ramrod on the Evolution project, and Ong deserves the lion’s share of credit for keeping the Evolution on track and driving it through to completion. According to Bowen, Ong is an expert designer and outstanding airframe stress engineer. Part of his job was weight reduction, generally regarded as the toughest mission in aviation, whether you’re building an airliner or an LSA. By a combination of black magic and collusion with the devil, Ong maintained the Evolution’s basic empty weight at 2,500 pounds against a gross weight of 4,300 pounds. With a standard 144 gallons of fuel on board, this means the basic payload remains well over 900 pounds.
It’s inevitable that the Evolution will be compared to the Lancair IVP, the company’s premier homebuilt product, but there’s very little similarity between the two airplanes other than carbon-fiber construction, side sticks and the nameplate.
In fact, the Evolution is an all-new, clean-sheet airplane deliberately intended to correct those features of the Lancair IVP that some owner/builders suggested needed revision. The Evolution’s pressurization system pumps up the cabin to a 6.0 psi differential compared to 5.0 psi on the IVP. The new model offers a 6,000-foot cabin at 25,000 feet and 8,500-foot atmosphere at the airplane’s 28,000-foot maximum approved altitude. Another benefit of the Evolution is that the baggage compartment is an integral part of the pressure vessel, so anything you store there will enjoy the same low-altitude benefits that you do. (In other words, no more exploding toothpaste.)
The Evolution’s fuselage is four inches wider and taller than the Lancair IVP’s cabin, a cylinder roughly 50 inches in diameter. Optimum build time on the Evolution is only 1,200 hours compared to a typical 3,500 to 4,000 hours for the IVP. Payload is 350 to 400 pounds more generous on the Evolution than on the IVP. Finally, the Evolution has conventional flight characteristics, whereas the IVP is a fully optimized experimental airplane, designed specifically for maximum speed, and that translates directly to a higher stall speed and higher approach speeds.
Twenty years ago, when I flew the Lancair IV for the first time with designer Lance Neibauer, I asked him what would be required to certify the IV. He laughed and commented, “There’s absolutely no way you could ever certify the Lancair IV. I designed it specifically as a high-performance homebuilt with speed as the primary goal. It’s not a dangerous airplane to fly, but the wing is optimized for cruise, and that means the stall is far too quick for certification.”
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