Nigel Hitchman/OSHKOSH
For years homebuilt aircraft have been at the forefront of technology in general aviation, while the development of production aircraft has progressed at a slower pace. Arguably, homebuilders have travelled a smoother path to creating their 'dream machines'. Unlike established general aviation manufacturers, they have faced neither certification constraints nor astronomical payouts resulting from product liability issues.
The annual Experimental Aircraft Association AirVenture show provides a forum for both markets and, thanks to recent industry-friendly legislation enacted by US Congress and the Federal Aviation Administration's simplification of the certification process for light aircraft, the distinction between both burgeoning sectors is becoming blurred.
Dominating the news at Oshkosh this year was the Eclipse 500, one of the small personal jets under development. Albuquerque, New Mexico-based Eclipse seems to have stolen the lead and could be the first to reach certification and production. First flight of the Eclipse 500 is set for June 2002 and certification for June 2003. The first aircraft will be built on hard tooling.
Eight aircraft will be used in the test programme: three flight-test aircraft, static and fatigue test specimens and three reliability growth aircraft. The latter will be tasked with flying 5,000 representative fleet hours before first delivery. By flying the aircraft as they will be used in service, Eclipse hopes to deliver a mature and reliable aircraft with teething problems already ironed out.
Vantage point
VisionAire displayed a fuselage mock-up of its redesigned single-engined VA-10A Vantage. Technical and financial problems led to the changes and work is under way with designer Burt Rutan to complete the modifications, with first flight of the revised prototype expected later this year. Scaled Technology Works is to build the three flight-test aircraft, with the first due to fly in mid-2001. US certification is expected towards the end of 2002, with the first deliveries in the first quarter of 2003.
In the background, VisionAire is continuing work on its Spirit family of personal jets. These single-engined aircraft will be designed around a new small turbofan and the Ames, Iowa-based company is looking at both the Williams FJ33 now in development and Pratt & Whitney Canada's proposed PW6XX powerplant.
Another all-new design, Century Aerospace's CA-100 Century Jet, is targeted at the entry level business jet market, pitched below the Cessna Citation CJ1 and the Raytheon Premier I. Direct operating costs are said to be only $335/hour - well below those of most turboprop or piston twins. Powered by two 1,200lb-thrust (5.5kN) FJ33-1s, the Century Jet boasts a cruise speed of 370kt (685km/h), range of 2,775km (1,500nm) and useful load of 1,350kg (2,970lb). First flight is set for 2002, followed by certification a year later.
At the other end of the jet spectrum is the ViperJet - a fully aerobatic kitplane with a 360kt cruise which looks like a scaled-down Northrop T-38. Construction is of carbonfibre, with tandem seating for two and full dual controls. Powered by a General Electric T58 turboshaft modified to produce 1,000lb thrust, the ViperJet has a maximum gross weight of 1,450kg, giving a useful load of 545kg. Take-off distance is only 2,800ft (856m) and best climb rate up to 23m/s (4,500ft/min). Kits are available and the ViperJet is expected to be cheaper to operate than the ex-military jets now becoming popular.
Another aircraft powered by modified T58s is the Maverick four-seat twinjet. A prototype has been flying for around a year and plans call for the aircraft to be certificated and produced in Poland. As well as being offered as a personal jet, the Maverick could find a market as a trainer for people stepping up from piston twins to new small jets such as the Eclipse.
Lancair HITS
Lancair was one of the first companies to announce plans to build a certificated aircraft based on one of its kitplanes when the revised FAA certification rules were introduced in the mid-1990s. The Bend, Oregon-based company delivered its first Columbia 300 certified aircraft earlier this year. Lancair has been working closely with NASA, under the Advanced General Aviation Transport Experiments (AGATE) programme, and the list of new technologies in the Columbia 300 is impressive. They include natural laminar flow, spin-resistant wing leading edge, simplified composite manufacturing, increased crashworthiness and an advanced glass cockpit.
Lancair is developing a turbocharged version, the Columbia 400 powered by a Teledyne Continental TSIO-550, and the prototype is being used also for "Highway In The Sky" (HITS) development. Another NASA programme, HITS is an integrated avionics system with full airliner-like primary flight and navigation displays. Other functions will be added later, such as uplinked weather information. The system is fed by an air data attitude and heading reference system (ADAHRS) as well as the global positioning system (GPS). The HITS system is being developed by Avidyne (software) and Avrotech (hardware). Certification is expected in the first quarter of 2001, leading to deliveries by year-end.
Cirrus is the among the most successful of the new companies offering certificated aircraft, having delivered over 50 SR20s of 620 on order. The Duluth, Minnesota-based company started life designing and producing the VK-30 four-seat pusher kitplane, but soon changed direction to pursue its goal of the certificated SR20. Production is up to two per week and will increase to one per working day by the end of the year. Cirrus' plant is capable of producing up to 800 aircraft per year. Fuselage production is moving to the Grand Forks, North Dakota, plant where many individual parts are now produced. Wing production and aircraft final assembly will remain in Duluth.
With European and Canadian certification of the SR20 now in progress, Cirrus has begun development flying with a derivative dubbed the SR22. This is a more powerful, higher weight aircraft. Power comes from a 230kW (310hp) Continental IO-550, and gross weight is increased to around 1,540kg. Wingspan is increased 0.64m (25in) to handle the extra weight, and also contain extra fuel, by an extension of the wingtips. Certification of the SR22 is expected at the end of this year.
Formal announcement of price and specification is due within three months. Cirrus believes the SR22 will be the first piston-engined aircraft to be certificated for instrument flight rules (IFR) operation with no vacuum system. It will be all-electric, with dual alternators and battery system with a fail-operational/fail-safe design. This level of redundancy in the electrical system paves the way for full-authority engine controls as they become available for piston-powered aircraft.
Swiss to watch
One of the most exciting aircraft on show at Oshkosh was the Aeris 200 from Aceair, a new Swiss company with a revolutionary design featuring three lifting surfaces - wing, canard and horizontal tail. The sleek fuselage is a step away from conventional light aircraft and reflects the automotive market criteria of maximum comfort and "quality of life" for the occupants.
The aircraft has been designed to comply with European JAR 23 certification rules and has been computer-crafted using computational fluid dynamics and finite element structural analysis design tools. Construction is of lightweight composites. All moulds and jigs for construction have been made using computer numerical control machinery, ensuring all parts are produced accurately. The Aeris 200 will be supplied initially as a kit but, as it is already designed to JAR 23 and will meet tough Swiss kitbuilt aircraft certification rules, it may be fully certificated at a later date.
The aircraft's power comes from an 80kW Mid-West AE110 rotary engine driving a three blade, constant-speed MT propeller via a carbonfibre driveshaft. The rotary engine offers smooth performance and is located behind the passenger cabin, with two scoop inlets under the wing roots for cooling. An empty weight of only 300kg and a maximum take-off weight of 580kg gives room for a 200kg payload with 110 litres (24gal) of fuel. The light weight and sleek design supports claims of outstanding performance, with a cruise speed of 180kt and stall speed of only 61kt. Take-off distance to 50ft is only 450m and range at max cruise power is 1,600km. A ballistic recovery parachute is offered as an option.
Two radio-controlled scale models of the Aeris 200 have undergone extensive flight testing, and another model has gone through aerodynamic testing in a windtunnel in Zurich. Construction of the proof-of-concept aircraft began in February, and the first flight has been set for January.
Power plays
A key to aircraft development is the availability of modern engines, and in the airliner and business jet world, airframe development has paralleled engine advances, resulting in today's quiet, efficient aircraft. In the light aircraft area, however, certificated engines designed before the Second World War are still being used - with few changes. In the homebuilt arena, attempts to produce a good aircraft powerplant by converting car engines have generally proved unsuccessful. The exception has been the use of Volkswagen engines in very low-powered aircraft. The few successful new engines that have cropped up, such as Bombardier's Rotax range and now the Jabiru engine from Australia, have been at the low-power end of the market. Electronic ignition has been borrowed from car engines with some success, although most aircraft still have old magneto ignition systems.
NASA's General Aviation Propulsion (GAP) programme has spurred Williams' development of a new engine for small jet aircraft and its other big success looks to be in producing a diesel engine for general aviation aircraft. Continental is testing its 150kW water-cooled GAP engine, with the goal of reducing fuel consumption by 25% and purchase cost by 50% and increasing time between overhauls by 75%, when compared to today's equivalent engines. Using Jet A1 fuel also overcomes the lack of availability of aviation gasoline in some countries and it is also much cheaper in Europe.
Leading the way in diesel engine development is a Snecma-Renault venture with its SR305 Jet A1-powered piston engine. Certification is due in Europe at the end of this year and by mid-2001in the USA. A partnership has been formed with EADS(European Aeronautic Defence and Space), Snecma and Renault Sport to continue the development, certification and production of the engine.
The SR305 will give much reduced operating costs, with lower consumption of cheaper fuel. Maintenance costs are set to be reduced by half, with the lack of magnetos and spark plugs, the use of direct fuel injection and integrated computer diagnostics combining to give an impressive time between overhauls of 3,000h. Single- lever control will also make flying easier.
Not all new
New designs do not necessarily reflect all that is new (or relatively new) on the market, however. For instance, Waco Classic of Battle Creek, Michigan, has just delivered its 91st YMF-5C aircraft in over 10 years' production. Little has changed from the day the original Waco YMF-5 which first flew in 1935.
But Florida-based Micco Aircraft, meanwhile, has clinched certification of its SP20, an updated version of the Meyers 145 first produced in the late 1940s. And American Champion Aircraft came to Oshkosh touting the prototype of its new Jabiru 2200-powered 7ACA Champ - the ancestry of which dates back to the Aeronca 7AC Champ.
Despite the general aviation industry's revitalisation, this year's Oshkosh confirms the major growth continues to be in the kitbuiltsector, where everything from the smallest, slowest ultralight to the most modern, super-slick speed machine is on offer.
Source: Flight International
