Uncrewed Systems Technology 046

92 In operation | Vantis BVLOS network Pre-flight planning and set-up The development of uAvionix’s test aircraft in the lead-up to the flight trials was a short affair, taking less than a month to get in the air after concept work began, although some fine-tuning of its geometries and componentry has been carried out to improve flight performance. “We record and log every flight, and our total air time comes to around 120- 150 hours now,” Clark says. “Preparation for each flight starts about a week in advance. First, Thales provides flight test cards, which include .KMZ overlays of where we’re going to be flying, what patterns we’ll be flying in, approximate flight times and key locations of strategically placed visual observer personnel to ensure constant VLOS of the aircraft.” Matus adds, “Thales coordinates closely with the NPUASTS on the flight cards. That coordination ensures the cards are aimed at testing end-to-end system connectivity over the C2 link, such that the aircraft maintains constant comms with the network.” While some flights take place in areas generally familiar to Clark and his immediate team members, inevitably some will be in completely new locations, meaning a day or so of site surveys will be needed. Once the area’s geography is understood well enough, the team takes two vans containing the UAV and its GCS hardware. Set-up takes about 5-10 minutes for all the necessary equipment. “We then set up some local antennas on the vans,” Clark says. “They aren’t totally necessary, because the UAV should be constantly connected to the GCSs through local Thales connectivity systems – which typically they’ve installed on their radar towers or some nearby cellphone towers – but our antennas bypass all the other networks to connect to our C-band radios, for a guaranteed back-up in case of network outages. “At the same time, we go through the logbook and make sure everything checks out with all the aircraft and ground computer subsystems. That’s currently a paper logbook but we plan to upgrade to an electronic, automated system in due course, which will streamline the pre-flight stuff nicely. Effectively that will be a digital checklist and a set of equipment status logs, combined and integrated into a GCS. “It’s standard for us to go through a pretty rigorous pre-flight check, particularly close inspections of servos, hinges and joints, given that the UAV will usually have been bouncing around in the back of a van for a couple of hundred miles. It’s also checked for GNSS, for timing as per the PPS pulses, and for accelerometers and gyros.” The team will also initially test the UAV’s data links and command responses using its local antenna. That will include lifting up the aircraft on one side to see if it tries to autocorrect itself, validating that its stabilisation and computer control systems are working correctly. It will then be connected to Thales’ equipment in the network. Some safety and operational briefings follow, including reviews of weather and other environmental risk factors, and launch typically starts within 90 minutes of having arrived at the test site. Test flights Some key equipment is critical to the safety of uAvionix’s UAVs as they fly across the Vantis area. For one, the Terma Scanter radars and the core Vantis interface software (from Thales) collectively provide a ‘tracker’ functionality, which as per traditional air traffic control systems fuses all the information on nearby non-cooperative aircraft into single targets that are visible via the GCSs as moving targets and data overlays. That provides effective collision avoidance. “The core software has been developed by leveraging elements of Thales’ TopSky UAS Airspace Manager software, adapted to meet the maturity level requirements identified in the FAA Safety and Risk Management Process,” Matus says. “That, coupled with health and status monitoring for the Vantis infrastructure sites, embodies a complete ‘mission and airspace management concept’ that is critical to supporting BVLOS UAV operations.” Ramsey adds, “The TopSky-based front end is what we plan our flights October/November 2022 | Uncrewed Systems Technology Thales also uses Terma’s Scanter radars, for detecting crewed aviation, as not all flights use ADS-B (courtesy of Thales)