Issue 40 Unmanned Systems Technology October/November 2021 ANYbotics ANYmal D l AI systems focus l Aquatic Drones Phoenix 5 l Space vehicles insight l Sky Eye Rapier X-25 l FlyingBasket FB3 l GCS focus l AUVSI Xponential 2021

97 AUVSI Xponential 2021 | Report The two-stroke 24 bhp engine is now being used in Martin UAV’s new V-Bat 128 ( UST 15, August/September 2017) among other unmanned aircraft, and recently passed the US FAA’s Federal Acquisition Regulation 33.49 endurance test run, a key milestone towards certification. As Bob Schmidt told us, “Suter’s facility in Turbenthal [in Switzerland] has a test cell dedicated to UAV engine cycling, in which we can run the engine on a dyno or via a propeller test. “The testing confirmed the TOA288’s maintenance interval hardware change- out, so we only expect to change standard service parts such as spark plugs, air filters and fuel filters prior to an overhaul, and no mechanical hardware will need to be replaced during the interim maintenance.” The TOA288 typically powers Group 3 UAVs, but can use a reduction drive (such as those typically found on manned aircraft) to propel larger aircraft. These solutions use larger propellers at lower revs to increase thrust and reduce noise compared with using a higher horsepower engine to spin a smaller propeller. Future plans by CAE include the development of water-cooled and heavy- fuel versions of the TOA288. “NATO has a one-fuel policy that eliminates gasoline use in UAVs for safety reasons, and requires them to run on jet fuel because it has lower volatility,” Schmidt explained. A water-cooled version of the TOA288 is expected to boost power output to 27 bhp without upping specific fuel consumption through improved thermodynamics and therefore more stable internal temperature-holding than in an air-cooled system. It could also be easier to install and use, as a UAV manufacturer would not need to design for cooling airflow during hover stages. TOA stands for Twin-Opposed Air-cooled so the new water-cooled variant will be TOW, or Twin-Opposed Water-cooled. Domo Tactical Communications (DTC) showcased its software-defined radio (SDR), the SOL8SDR2x1W-P, which has been designed to provide high- speed, long-range, encrypted data links at a size, weight and power low enough for unmanned platforms. “The SOL8SDR2x1W-P joins DTC’s family of IP mesh and point-to-point COFDM radios,” commented Rob Garth. “Based on DTC’s SOL8 SDR, the SOL8SDR2x1W-P can operate as a Mobile Adhoc Network [MANET] IP mesh node, a point-to-point COFDM transmitter or a point-to-point receiver to a tablet PC. “Also, every DTC SDR and NetNode system can host our MeshUltra waveform, enabling commonalty of mesh networking across all deployed radios. MeshUltra was developed for spectrally efficient, high-bandwidth comms in challenging, dynamic, non-line-of-sight environments and BVLOS for airborne ISR platforms.” The MeshUltra waveform can operate at various RF channel bandwidths from 1.25-1.5 MHz, 1.75 MHz, 2.5 MHz and up to 20 MHz. With adaptive modulation up to the 64QAM standard, MeshUltra also supports data rates of up to 87 Mbit/s. The SOL8SDR2x1W-P typically consumes 10 W during operation and includes native Ethernet, dual USB and serial among its interface options, as well as an audio headset socket. “DTC has also developed a new MeshUltra-X waveform, offering optimised performance for large networks consisting of up to 144 radios, and operating in channels as narrow as 1.25 MHz, and on a single frequency,” Garth added. “We anticipate that this will meet the needs of large UAV swarms, and other applications where a large number of radios need to operate efficiently in a limited spectrum.” Unmanned Systems Technology | October/November 2021 The TOA288 from Suter recently reached a key stage towards FAA certification