Tuesday, July 31, 2007

Evektor SportStar: Czech Mate

Mostly metal and all fun, the Evektor SportStar brings its own formula to the LSA class

By Bill Cox
Photography By Jessica Ambats

The category is called light-sport aircraft, and one look at the Evektor SportStar suggests that it practically defines the type. A product of the Czech Republic’s largest aircraft manufacturer, Evektor-Aerotechnik of Kunovice, the SportStar is one of many products from a company with a prestigious international client list—Boeing, Mercedes, Volkswagen, Let Aircraft and others.

Evektor was established more than 35 years ago, specifically to build motorgliders and autogyros, and the company’s fortunes have since expanded to include production of a variety of aerospace components. Gross sales in 2004 topped $50 million, and the company has some 450 employees.

Like all the other LSAs, the SportStar mounts two seats and is restricted to 137 mph. Unlike many of the others, however, the airplane has the distinction of having been the first LSA certified in the United States. The Eurostar, Evektor’s European version of essentially the same airplane, has been selling overseas in 30 countries for years, and there’s a fleet of nearly 500 airplanes already in the air.

Little surprise there. The airplane is built hell-for-stout, constructed on a production line in Eastern Europe that also produces fully certified, normal-category aircraft. The SportStar isn’t an aerobatic airplane (though it looks as if it should be), but it’s nevertheless built to withstand acro G loads of +6/-3.

Evektor disdains composites, preferring to build the SportStar primarily from all-metal materials, mostly Alclad 2024 Duralumin alloys. The fuselage, wings and empennage are constructed mostly of aluminum, with the occasional use of other metals—galvanized steel on the firewall, for example. (Inevitably, the airplane does incorporate a limited amount of composites in those areas where they make sense—wheel fairings, wingtips, gear legs, etc.)

The SportStar features riveted, nearly all-metal construction, but despite its use of metal, it’s hardly a conventional machine. The engineers at Evektor were well aware that rivets tend to work and loosen over time, so surfaces and structures are attached with a combination of rivets and bonding. This holds the rivets firmly in place and helps provide a stronger airframe and wing.

The SportStar has a definite look of a sport plane with its low wing and bubble canopy. In this case, “bubble” is definitely the operative term.
The airplane’s most prominent feature on the ground is that large, bulbous expanse of Plexiglas. The canopy actually bulges as it rises from elbow height, providing additional width at shoulder level. The good news is that visibility is excellent in every direction except straight down. The not-so-good news is that the bubble is so all-encompassing that it acts like a greenhouse and heats up in summer. Fly high.

The airplane’s cabin is a surprising 46.5 inches across, wider than most other four-seat singles, much less two-seat sport planes. The glass bubble also is large enough to accommodate pilots as tall as 6’ 2”.

Gross weight is set at 1,212 pounds, and Evektor suggests a standard airplane goes out the door at an empty weight of 668 pounds. That leaves a useful load of 544 pounds. Subtract a full service of fuel, and you’re left with 358 pounds for people and stuff in the baggage area (stuff can weigh up to 50 pounds). A pair of 180-pound pilots will bring the airplane to gross. Fortunately, the SportStar’s configuration provides a CG envelope that’s wide and forgiving.

Pilot and passenger ride high in the SportStar, elevated enough to allow a clear view straight back at the vertical tail. A number of military fighters feature the same seating configuration, actually positioning the pilots above the top fuselage line to help them spot threats from their six. The large, tinted canopy hinges at the front and folds forward via two gas cylinders for entry/egress, so it can’t be opened in flight.

Looking out from the left seat, you’ll note a smooth, simple, functional wing design, nearly rectangular in shape with a single spar at center chord, no taper and no noticeable dihedral. The wing is somewhat reminiscent of a Tiger’s airfoil in appearance, if not in technical description. The wing features split flaps, so the top surface is uninterrupted during flap operation. Standard flaps are manual a la Cherokee with a center-mounted Johnson bar lever, and they provide 15, 30 or 50 degrees of deflection. Electric flaps are an option, with infinite flap positions. Deploy those huge lift enhancers, and stall drops to less than 40 knots.

The trapezoidal empennage is relatively conventional in design and construction. One Evektor option is a tow mechanism directly beneath the tailcone that allows glider or banner towing.

Out on the pointy end of the airplane, the propeller is a two- or three-blade tractor, ground adjustable for cruise, climb or any setting in between. The SportStar’s motive force is a four-cylinder, four-stroke Rotax 912ULS, cranking out 100 hp at the max-rated 5,800 rpm and spinning the prop through a reduction gearing system. METO power (maximum except takeoff) after five minutes is 5,500 rpm, and cruise is recommended at 4,800 rpm, generating about 71 hp. Redline for takeoff is 2,700 prop rpm, and cruise is recommended at 2,150. The Rotax’s cylinder heads are water-cooled, while the cylinders themselves utilize more-conventional air-cooling. TBO is 1,500 hours.

(Incidentally, the SportStar is also available with an 80 hp version of the same engine. Only climb suffers with the derated engine, as it’s approved for operation at the same max cruise setting of 4,800 rpm, again worth 71 hp.)

The aircraft’s ground handling is excellent, with a turn radius of less than 30 feet. If you can drive a Cherokee or Skyhawk around the ramp, you should be right at home in the SportStar.

With its current gross weight of 1,212 pounds and the “big” engine, the SportStar boasts a climb rate of 840 fpm. That’s a reasonable number for only 100 hp. Better still, service ceiling tops 13,000 feet. This is no ultralight. Sometime down the road, SportStar may opt for a higher gross weight, as the LSA limit is 1,320 pounds, still more than 100 pounds away.

Choose to cruise at a typical 6,500 to 7,500 feet, and you’ll see reasonably good speed. Evektor recognizes that cruise is conditional upon a dozen factors that aren’t always controllable, and for that reason, they set the max cruise number at a variable 100 to 110 knots. Economy cruise is pegged at 95 knots.

The SportStar isn’t strictly about speed, however. The cabin is large and comfortable, vibration is minimal, and the noise level is reasonable, so the airplane should make a good platform for cross-country transport. Fuel capacity is 31.5 gallons. Burn is about 5 gph, so you could reasonably plan four- to five-hour trips without stretching reserves. In no-wind conditions, that means you could fly cross-country legs as long as 550 nm—Los Angeles to Albuquerque, Dallas to Denver or Chicago to Atlanta—in one hop.

In-flight handling characteristics are pleasant without being super quick. Roll rate is on the order of 40 degrees per second, and pitch authority is well harmonized. Unlike some other LSAs, the SportStar manifests a reasonable amount of adverse yaw. That means you’ll need to relearn the use of rudder to coordinate turns greater than 10 degrees of bank.

Power-off glide at 50 knots results in a sink rate under 500 fpm. If the Rotax stops unexpectedly and you’re 7,500 feet above near-sea-level terrain, you’ll have about 15 minutes to find an appropriate parking spot. Stalls are fairly benign, with little tendency to spin. Published dirty stall is 39 knots, and in combination with effective brakes, that translates to good short-field characteristics, well under 700 feet for both takeoff and landing.

Landing characteristics don’t present any special challenge. It’s easy to rotate the nose to a comfortable, high angle of attack for touchdown on the mains, then lower the nosewheel to the asphalt. Braking is with standard toe brakes.

The airplane I flew was out of Sport Planes West [www.sport planeswest.com, (951) 765-5020] in Hemet, Calif., one of five American dealers. The folks in Hemet’s suggested base price for the standard SportStar is $104,950 with an operational stack of VFR radios and instruments. Add most of the options the majority of pilots would normally select (including an autopilot), and you’ll have a fully operational cross-country machine for about $113,000.

Light-sport aircraft have become a force in general aviation in the last two years, and as the first certified LSA, Evektor’s SportStar is one of the leaders of the pack. It’s a little more expensive than some other models, but if you’re looking for a big cabin, good performance and economical operation, the SportStar may be an ideal ticket to ride.

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