An EC-funded research project has unveiled its proposals for a new generation of aircraft that are intended to give Europe the edge in the civil UAV sector
Three years after its launch, the European Commission-funded CAPECON civil unmanned air vehicle design project has unveiled proposals for a new generation of aircraft intended to significantly improve UAV reliability, facilitate air-traffic integration and reduce overall acquisition costs.
Comprising four high-altitude and two medium-altitude, long-endurance (HALE and MALE) fixed-wing UAV designs, plus two rotary-wing UAVs, the designs are to be put forward for potential development as part of the new European civil UAV roadmap being prepared by the European Commission's UAVNET project.
The eight platform proposals are about to be joined by a series of designs for new-generation small civil-application UAVs, the initial concepts for which were revealed at the UAVNET 13 meeting in Eilat, Israel, in mid-May. These configurations include a concept for an electrically powered version of the Israel Aircraft Industries (IAI) I-View military UAV; a combustion engine-powered twin tail-boom version of the same aircraft; a larger version of the IAI Bird Eye mini-UAV series; and a wholly new lightweight, electrically powered mini-UAV.
The additional designs mark a major shift in CAPECON and UAVNET thinking, as both projects identify small UAVs as the most likely platform class to open up a viable civil UAV marketplace in the near term. Original project thinking had anticipated that commercial applications would be led by the HALE and MALE sectors. According to Akiva Peled, deputy preliminary design manager at IAI and CAPECON co-ordinator, when the project was launched "small-size UAVs were intentionally omitted from the study, [the assumption being] that they would not meet the safety/regulatory criteria of civil aviation.
"However, technology evolution – miniaturisation of avionics, payloads and propulsion – indicates potential viability for such configurations. Therefore a market survey and definition of mini- and small-UAV configurations similar to the three main-category UAVs defined in the original study – HALE, MALE and rotary – were added to the extended CAPECON programme."
The CAPECON designs have emerged from a unique multinational collaborative effort between some of Europe's top aerospace design organisations, along with a range of academic and industrial partners. CAPECON – officially known as the Civil UAV Applications and Economic Effectiveness of Potential Configuration Solution project – and UAVNET were funded as part of the European Commission's Fifth Framework agenda to promote competitive and sustainable growth in the aerospace sector. IAI co-ordinates both initiatives.
The CAPECON project kicked off in May 2002. Key industrial participants included Agusta, EADS, Eurocopter and Swedish Space Corporation. National research agency involvement included ONERA of France, CIRA of Italy, DLR of Germany, INTA of Spain and NLR of the Netherlands. Among academic partners were the Warsaw University of Technology (WUT), the University of Bologna, Turin Politecnico de Torino (Polito), the University of Naples (Unina) and the Israel Institute of Technology. Initial European Commission funding supported a 30-month programme, but, with the extension to enable consideration of the small civil UAV segment, the project will now end later this year.
The project initially identified and defined a broad range of potential applications in which a civil UAV could offer improved mission, and, in particular, cost-effectiveness compared with manned aircraft. Member organisations were then commissioned to develop new-generation designs that would significantly improve air vehicle reliability and safety compared with existing UAVs. They would allow easier integration into non-segregated airspace, and would be cheaper to build and operate.
The design teams were given the target of achieving a mean time between UAV loss of 100,000h, coupled with a mean time between subsystem component failure of 1,000h. Given that take-offs and landings are the most likely time for a UAV to have an accident, CAPECON also set a target of 1 million hours' mean time between air-vehicle losses from uncontrolled landings.
Technological improvement goals of 20-30% were mandated for aerodynamic and propulsion efficiency, along with the goal of a 15-25% reduction in structural weight compared with current state-of-the-art civil manned aircraft and military UAV designs. Propulsion efficiency goals were divided between reductions in propulsion system weight and savings in fuel consumption.
A common evaluation methodology was also developed, resulting in a toolset that allowed potential missions to be measured against platform capabilities and attributes. This approach was used to group potential missions by common attributes, refine the number of UAV designs progressed to an advanced stage, and to "stream" those designs to meet grouped mission needs.
Baseline configurations
Peled says the eight existing configurations developed by CAPECON, as well as the small-UAV designs now being developed, will be the "baseline configurations for UAV systems demonstrations of the roadmap and for the developed configurations in the next phase. Nevertheless, whether it will be these configurations that will continue on to the next phase, or whether further technological developments will favour more suitable configurations, the same methodology used for CAPECON will continue to be used for all required UAV configurations and systems." The four proposed HALE configurations comprise a solar/fuel-cell-powered aircraft designed by Polito; two separate twin-turbojet, blended-wing designs by ONERA and WUT; and a modular twinjet design from IAI.
Professor Giulio Romeo is head of aeroplane design and structures at Polito and leader of the CAPECON HALE working group. He says the four designs indicated a common requirement for ongoing technical development within Europe in the area of lightweight, low-cost airframes, particularly regarding wing elasticity and overall platform aerodynamic performance. He also suggests there is potentially a need for a common-core UAV command-and-control architecture that can be transferred between any type of air vehicle.
Helios lessons
Polito's Solar High Altitude Multi Payload Operation design is intended to support endurance missions of 4,000-5,000h each, using eight electrically driven propellers powered by a combination of wing-mounted solar cells and central fuselage-located fuel cells.
Romeo says the design was heavily influenced by preliminary lessons from the loss of NASA's Aerovironment Helios solar-powered UAV off Hawaii in mid-2003, resulting in considerable work being devoted to wing flexing and airframe stability issues. The primary missions would be wide-area communications relay and earth observation.
ONERA's OBW-02 blended-wing HALE is intended to support fast-reaction observation missions over 24h. It would be capable of reaching altitudes of 50,000ft (15,240m) in 20min. The design has a wingspan of 30.4m and a maximum take-off weight of 5,400kg (11,900lb).
The Warsaw University of Technology's PW114 HALE design has a span of 28.5m and a maximum take-off weight of 6,350kg. Maximum payload capacity is 700kg and, according to Professor Zdobyslaw Goraj, head of WUT's aircraft and helicopters department, a production-ready PW114 would potentially cost about ?5.3 million ($6.65 million) per aircraft, including payloads.
IAI's modular HALE system is the heaviest of the three jet designs, with a maximum take-off weight of 8,000kg, but it is intended to support as broad a range of mission applications as possible. The modular approach includes wing and fuselage sections, as well as the design of the payload bay, which would be able to support a maximum load of 500kg. While developed under the auspices of CAPECON, the design may be progressed further by IAI as its launch platform in the HALE sector, under the designation HA50. Shlomo Tsach, director of flight sciences at IAI, said at the Eilat meeting that the company is looking for industrial partners and potential customers to progress the design to full-scale development.
All three CAPECON jet-powered HALE designs would use existing versions of the Williams International FJ44 turbojet family. Romeo says a potential high-value area of future enabling technology for UAVs would be a common European co-operation project with Williams to optimise the FJ44-4 variant for HALE applications.
MALE concepts
The two MALE concepts were developed by Unina and WUT. The Unina concept is for a 30h endurance platform powered by a Pratt & Whitney Canada PT6 turbo-prop with a pusher propeller. The UAV would have a maximum take-off weight of 2,720kg with a span of 24.5m. The design would be capable of remaining on station at 1,000km (540nm) range with a 500kg payload for 24h.
WUT's MALE proposal, designated PW103, is based around a Thielert TAE 125 diesel engine and five-blade pusher propeller mounted in a twin tail-boom configuration airframe. The UAV would have an endurance of around 16h with a payload of 217kg and a maximum take-off weight of 930kg.
The all-composite design, which would have a span of 12.6m, also includes options for a secondary emergency propulsion system, comprising a nose-mounted Wankel AAI AHF-12 engine with a two-blade folding propeller covered by a disposable cowling. In the event of main engine failure, the secondary system would automatically be activated and would enable the aircraft to fly an additional 50km to a safe landing site. Goraj says a production-ready PW103 would have a unit cost of around ?1.8 million, including payloads.
CAPECON's two rotary-wing designs were based on the extrapolation of two core sets of missions. The first of these – for a vertical take-off and landing UAV to perform local area surveillance roles – saw AgustaWestland develop designs for a 260kg maximum take-off weight classical helicopter configuration with a 4.2m rotor diameter. The aircraft would be powered by a Rotax 912ULS engine and have a ceiling of 6,000m and a maximum speed of 86kt (160km/h). The UAV would have a radius of operations of 25km.
The second set of VTOL missions called for the UAV to perform a variety of surveillance and monitoring roles, such as powerline inspections and area searches. Eurocopter's proposed solution is a coaxial rotor design with teetering hubs and a 2.55m rotor diameter. Power would be provided by a Thielert Centurion 1.7 diesel engine, with maximum take-off weight projected at 550kg. Maximum speed would be 97kt and maximum altitude 14,100ft. Eurocopter suggests the cost of developing the UAV to production standard, with this including construction and testing of three prototypes, would be in the order of €39 million.
Small UAV
IAI heads the CAPECON small-UAV design effort, and initial concepts focus on a low-cost system comprising two UAVs as well as a small van to house the ground-control station. The van would also support a fold-down, roof-mounted rail launcher. Recovery options include runway and parafoil with parachute as an emergency back-up.
The proposed K70E6 electric-powered version of the existing IAI I-View K50 UAV would have a maximum take-off weight of around 70kg with battery-weight projected at 28kg. The engine would produce 6hp (4.5kW) and provide a maximum speed of 87kt. The UAV would have a span of 6.4m and endurance of 3h for the basic model, or up to 5h for future versions.
IAI's proposed K70T is a twin-boom I-View derivative with a span of 4.6m and a payload of 13kg. The UAV would have a maximum take-off weight of 75kg and an endurance of 8h; maximum ceiling is 20,000ft. IAI has investigated a variety of configurations for the design, including separate-set V-, L- and H-tails, plus low-slung and high fuselages.
The new K10 small-UAV concept is based on a twin-engine, twin-tail above wing-pod fuselage arrangement. The electrically powered aircraft would have an endurance of 3h and would be capable of carrying a payload of up to 2kg. The UAV would have a 3m span and use a parafoil recovery system.
The baseline modified IAI Bird Eye 500, designated Bird Eye 500M, would see an increase of the existing UAV's wingspan from 2m to 2.4m and the introduction of a parachute landing system. The existing Bird Eye 500 forward fuselage would receive a small extension plug, with maximum weight rising from 3.65 to 5.6kg.
Another version, designated Bird Eye 500D, would incorporate the same forward fuselage extension, but would use deep-stall landing techniques. The 500D would also feature the 2.4m wingspan, but maximum weight is projected at 4.9kg.
PETER LA FRANCHI/EILAT
Source: Flight International
