The Annual Experimental Aircraft Assn. (EAA) International Fly-In Convention and Sport Aviation Exhibition, still known to aviation aficionados as the Oshkosh Fly-in, was held at Wittman Regional Airport, July 22-29, in Oshkosh, Wis. EAA president Paul Poberezny, the son of the man who started the aviation club that became EAA in his Milwaukee basement in 1953, called it the best Fly-in ever. In the composites arena, the big news at Oshkosh was small planes, notably, a crop of new light sport aircraft (LSAs) and very light jets (VLJs).
Light sport aircraft (LSA)
The loudest noise in the LSA market has nothing to do with composites but, because of its potential impact on the market, can’t be skipped: Cessna (Wichita, Kan.) has entered the fray with a all-metal aircraft. Cessna’s 162 SkyCatcher fits all the criteria for LSA status. However, this large fish is jumping into an increasingly large pond dominated by designs that make significant use of composites.
Shortly after LSA regulations were finalized, there was an influx of LSAs from Eastern Europe (see “Related Content”, at left) — adaptations of planes previously built to Europe’s Microlight standard. These included the Sting Sport, a sharp little all-composite, low-wing LSA from the Czech Republic, imported by Sportair USA (St. Petersburg, Fla.). Sportair was back at Oshkosh this year with a high-wing model named the TL-3000 Sirius. But there was no dearth of domestic examples at Oshkosh. Cirrus Design Corp. (Duluth, Minn.) jumped in with the Cirrus SR Sport. A variant of the 1990s-era microlight, the Fk 14 Polaris from Speyer, Germany-based airframer Fk, the composite, two-seat, low-wing monoplane with distinctive winglets features an otherwise conventional design with fixed undercarriage in either tricycle or tailwheel configuration. It is available factory-built or in kit form, and first deliveries are expected in late 2008. Alan Klapmeier, Cirrus cofounder and CEO, says that since the airloads encountered at LSA speeds/weights aren’t severe enough to justify an all-carbon airframe, carbon fiber would be used in the spar caps and in a few other highly stressed areas, while S-2 and E-glass will reinforce primary structures.
The top end of the spectrum
A number of new VLJs (very light jets) and hotrod turboprops were on display. The “new kid on the block” is Epic Aircraft (Bend, Ore.), which has scored a string of successful new-plane introductions in an amazingly short period of time. Its newest, the Victory, is a single-engine four- to five-seater. Although this entry-level jet’s published speeds — maximum cruise, 320 KTAS (knots true airspeed), economy cruise, 250 — are slower than some turboprops, it’s still a capable cross-country machine. Cost will be less than $1 million USD).
Epic’s twin-jet Elite seats up to eight people, with a maximum cruise speed of 412 KTAS; economy cruise, 385; time to climb, 17 minutes to a service ceiling of 41,000 ft. It will be certified with a Williams FJ-33-4 turbofan powerplant. The Epic jets will be offered in certified, factory-built versions, but also will come as kits. Both will have carbon fiber-reinforced airframes, but with a difference: The scarcity of 3K carbon, back when these planes were designed, prompted Epic to spec 12K, usually reserved in aerospace circles for tooling. CEO Rick Schrameck elected to go with the 12K, which was in plentiful supply at the time, and reports no difficulties with this approach, as is apparent from the speed with which the company got its prototypes airborne. The first took about 16 months from design to a flying prototype, but the Victory went that distance in five months. This kind of hustle hasn’t been seen since WWII, when the P-51’s metal airframe was developed in around six months.
Epic also has developed two new turboprops in factory-built or kit configuration: the four- to five-seat Escape followed by the six-seat LT. And there’s an FAA-certified version of the LT, the Dynasty. Schrameck says jet/turboprop production is backlogged to 2010 since Epic racked-up $23 million in sales at EAA’s recent Sun & Fun fly-in at Lakeland, Fla.
Another approach to turboprops was the Envoy series exhibited by Sreya Aviation (Santa Maria, Calif.). The series features a four-seat low-wing and a high- or low-wing six-seater, each available with fixed or retractable landing gear. The most notable feature is the advantageous “flattened” fuselage (top photo). Its low profile minimizes the wetted area, thus reducing drag. The Envoy airframe’s construction is fairly straightforward: fiberglass laminate shells for the skin, stiffened with foam-cored carbon fiber hat sections, patterned much like the stringers and formers in an aluminum structure. The wing is all-carbon except for the ribs. There are two spars, an I-beam forward and a rear box beam that transitions to an I-beam in the wing. When skinned, the I-beams form a large box beam.
Previously a kit plane source, Comp Air Inc. (Merritt Island, Fla.) unveiled the Comp Air 12. This 10-seat, low-wing turboprop has a get-up-and-walk-around cabin and won’t be offered as a kit. Intended to compete with Unlimited-class aircraft, it’s fronted by an unusually powerful 1,650-hp engine that will move passengers and baggage 310 KTAS at an altitude of 30,000 ft. Also on offer was the slightly smaller Comp Air 9, which seats eight and has a 1,000-hp powerplant.
Since most flight testing is finished on these two, Comp Air is directing effort to its Comp Air Jet. Powered by a single Honeywell TFE 731 turbofan, it can seat eight and cruise for 1,600 miles at 350 knots.
Comp Air relies primarily on solid laminates. Sandwich structure, with honeycomb, syntactic or board foam and sometimes end-grain balsa, are used only in small areas. This prevents water (and therefore, weight) accumulation — a serious consideration because many of these planes will be configured as amphibians.
Cirrus is pursuing a single-engine jet of its own called, simply, The Jet. Its pressurized cabin will seat seven (two on jumpseats) and it’s designed for single-pilot IFR (Instrument Flight Rules) use, with a 300-knot cruising speed and 1,000-mile range with reserve fuel. Although little was revealed about the materials (only a subscale model was on display), it’s likely to have a good deal of carbon aboard.
Finally, Diamond Aircraft Industries Inc. (London, Ontario, Canada and Wiener Neustadt, Austria) displayed a cabin mock-up for its forthcoming five-passenger D-JET, which the aircraft manufacturer is grooming for the VLJ market. Powered by a Williams FJ 33-4 jet engine, the 35-ft-long craft has a 37-ft wingspan. The light composite airframe on the overall 5,110-lb craft will give it a range of 1,350 nautical miles and permit operation on runways as short as 2,500 ft.
And points in between
In the midsized turboprop arena, Lancair (Bend, Ore.) has begun shipping kits for the ES-P, a pressurized version of its ES, with an all-carbon fuselage. The ES-P is designed for economy cruise at 270 mph at 17,500 ft, the maximum altitude for Visual Flight Rules (VFR), with a top speed of 293 knots (ES is 200) at 24,000 ft. The basic idea is to get the plane up into the thinner air to negate some of the fixed gear drag penalty. Lancair’s biggest splash, however, was the Evolution, a mock-up turboprop four-seater with a 30-ft-long (37-ft wingspan) contoured carbon composite airframe that doesn’t appear to have a straight line on it. It’s able to take off and land on runways as short as 1,000 ft and has a range of 1,290 nautical miles (maximum cruise, 338 knots). Three years in development, it’s built to Federal Aircraft Regulation (FAR) Part 23 standards. Five kits will be ready by year’s end, and the company says four are already sold.
Seawind (Kimberton, Pa.) is now delivering a certified version of its composite amphibian. The Seawind 300C, at 27 ft long with a 35-ft wingspan, is a four-seater that, at only 2,400-lb empty weight, can get off the ground or water fairly quickly, requiring only 1,175 ft of runway or 1,400 ft of calm sea. The company says it has 90 orders for the plane and expects to be capable of producing 200 per year by the end of 2009
Have we covered everything? Not even close. Suffice it to say, a lot of composites will be used in general aviation, with carbon use growing. It’s good to know the world’s carbon fiber suppliers are adding new capacity.