Taking the best out of a petrol engine powered rotary UAS and an electric motor powered one, in order to provide its customers with a highly flexible solution. This is what Steadicopter Ltd. of Israel, established in 2005 and that has since specialised in rotary wing unmanned air systems (RUAS), did with its Black Eagle 50 system, the new Black Eagle 50H being unveiled at the Singapore Air Show.
“We kept the air vehicle of the electric version, with some minor structural changing to be able to host the new hybrid powerpack that we took off the shelf,” Noam Lidor, VP Sales, Marketing & Business Development, tells EDR On-Line. The Black Eagle 50H adopts a serial hybrid configuration, in which the 120 cm3 2-stroke, liquid-cooled, boxer petrol engine is linked to a 7.5 kW generator that provides current to the electric motor as well as to the battery pack via a controller. The hybrid package has a weight of around 8 kg, which brings the dry weight of the air vehicle at less than 30 kg.
As said, dimensions remain those of the Black Eagle 50E, with a main rotor diameter of 2.8 meters, a total length of 3.1 meters, maximum take-off weight being also 50 kg. The same applies to speed performances, 70 knots maximum and 45 knots cruise, the airframe being able to operate in take-off and landing operations with winds up to 25 knots. Of course control laws remained similar, as well as the data link, the latter ensuring a range of 150 km.
Where things chance consistently is when we come to payload and endurance, the hybrid powerplant giving inherent flexibility to the airframe. “Here we listen first of all to our customers’ needs, in order to tailor the solution to provide them maximum endurance performances,” Noam Lidor explains. Steadicopter has in its catalogue two different fuel tanks, with respective capacity of 20 and 10 litres, while the battery bay can be tailored to the amount of elements the customer wants, depending on the electric-only endurance required, the third element being of course the sensor suite. “Our first customer required us to install a 3.5 kg sensor payload, the 20 litres fuel tank, and a battery package topping up the total payload, which gives him the opportunity to fully exploit the 150 km range of the data-link,” the company VP Sales and Marketing tells us. Depending on requirements, Steadicopter adopts either Lithium-Ion or Lithium-Polymer batteries. Of course much depends also on the mission profile.
Looking at average data provided by Steadicopter in its family brochure the 50H has a 5 hours endurance compared to the 2 hours endurance of the 50E (the petrol version having a 4 hours endurance, but this one is in fact a different airframe, with smaller dimensions and a 35 kg MTOW), while the hovering endurance is increased from 75 minutes of the 50E to 3.5 hours of the 50H, and here the mission profile comes into play. That said, when on target the Black Eagle 50H will go all-electric, in order to be as stealthy as possible, a standard battery package providing it around 30 minutes endurance; however it can eventually move out of the critical area, switch on the petrol engine, reload batteries and go back on target for a further 30 minutes run. Should persistent surveillance be needed, more than one airframe would ensure it, battery reloading taking less than 10 minutes once the engine is switched on. Steadicopter worked with Simplex to integrate the FlightOps drone control technology that allows to operate multiple drones, hence a multiple UAV operation on the same target is definitely feasible.
As said the sensor package is the other variable; according to the brochure the “E” version has a 15 kg payload capacity while the “H” version has 3 kg less, however what counts is the greater flexibility of the latter, which also has a slightly lower service ceiling, 16,500 ft versus the 18,000 ft of the all-electric. “That figure is the one provided by the hybrid powerpack vendor, and we have still to test it in real, however even if we would demonstrate a slightly lower capacity that would be plenty enough,” Noam Lidor states, underlining on the other side the importance of the water-cooling system adopted on the engine, which ensures good operational capabilities even in hot areas, the temperature limits declared for the Black Eagle 50H being –20°C and +50°C.
Steadicopter is proposing the hybrid version of its Black Eagle 50H for both military, security and civilian applications. The system is ready for production at the company facility in Migdal HaEmek, some 30 km southeast of Haifa. As EDR On-Line understood this should have already started for a first customer, more potential customers having already expressed interest for the new RUAS.
Photos courtesy J. Roukoz