BVLOS for UAVs: Technical and regulatory pieces start to come together at TTP workshop
TTP’s 2023 “Talk to the Eye in the Sky” workshop, co-organised with Cambridge Wireless, showed how the drone industry and regulators are making progress towards enabling routine Beyond Visual Line of Sight (BVLOS) operations.
Beyond Visual Line of Sight (BVLOS) has long been a key topic in the drone industry because, commercially speaking, it’s what will allow the industry to take off. Possible applications range from much talked about last-mile delivery, to more near-term infrastructure inspection and medical delivery in remote areas.
BVLOS will massively improve the scalability of UAV operations and enable several commercial use cases. But existing regulations do not accommodate routine BVLOS operations. In the UK, for example, BVLOS permits are currently time-limited in segregated airspace, and regulators are working to develop new rules to accommodate the commercial opportunity.
At TTP, we are taking a keen interest in this regulatory evolution, because it will play a large part in defining the capabilities of the technologies that will eventually enable autonomous drone operations at scale. We, therefore, began our workshop with a presentation by a regulator.
Edward Fitzpatrick, Regulatory Innovation Specialist, spoke about the importance of the UK’s Civil Aviation Authority (CAA) accords to BVLOS as a regulatory priority. He explained how the Authority works with the industry through its Innovation Advisory Services and Regulatory Sandbox.
“We are on a pathway to BVLOS Integration,” he said outlining the Authority’s current work to develop regulatory frameworks to enable “specific category” BVLOS operations in non-segregated airspace – meaning operations other than those that present the lowest risk to third parties.
The CAA is currently finalising a policy concept for an “Accommodation” phase leading from the segregation to the integration of UAV with conventional aircraft operations, he said.
Is there a schedule to move through all three stages from segregation, through accommodation, to the eventual integration of UAVs? Fitzpatrick was tight-lipped — but a regulatory sandbox for the BVLOS accommodation airspace policy concept was published shortly after the workshop.
From Electronic Conspicuity to Detect-and-Avoid
Gavin Goudie’s presentation about the BVLOS trials Blue Bear Systems Research Ltd undertakes at their facility near Bedford and the National BVLOS Experimentation Centre (NBEC), which runs from there to Cranfield Airport, included some memorable examples of the variety of airspace users, from military aircraft to student pilots, and the unpredictability of the air traffic UAVs will have to contend with during BVLOS operations.
Electronic Conspicuity (EC) will definitely be required, although we don’t know yet how effective this can be in mitigating collision risks, he said. But in aviation it’s difficult to guarantee that everybody will comply with Electronic Conspicuity mandates at all times (not to mention birds), so Detect and Avoid (DAA) capability will be inevitably required for last-resort tactical airspace deconfliction.
Radar can be part of the solution to detect airspace users that do not use EC. In automotive Advanced Driver Assistance Systems (ADAS), radar already has a track record as an obstacle detection technology. As Steve Clark’s presentation for Cambridge Sensoriis showed, the technology is mature enough to miniaturise radar-based DAA solutions to determine the location and relative velocity of obstacles in the flight path of UAVs. As a localisation technology, he also demonstrated how ground-based secondary radars can enable drone landing with inch-perfect precision.
Command and Control
Further presentations pieced together the multiple layers of communications required for 99.999% available Command and Control (C2), through terrestrial, satellite, peer-to-peer links, or high-altitude platform stations (HAPS).
Neal Unitt-Jones from Stratospheric Platforms Ltd Platforms described their HAPS platform in development and the potential connectivity gaps it can fill when it becomes commercially available. Although HAPS have not seen widespread adoption so far, Neal made the case that this would change with the power density of liquid hydrogen being key to their techno-commercial success.
Dave Pankhurst described how, in the last few years, drones have become a key area of focus for BT Group. This is clear from the involvement in the Future Flight Challenge and investment in leading UTM providers such as Altitude Angel. Ofcom’s announcement to enable 4G and 5G to be used for drones has given a boost to this, and BT has launched a drone e-sim on the back of this to tackle the key issues of base station interference and coverage.
Jon Holmes from Inmarsat talked about the role of satellite communications for both C2 and payload communications. He talked about the technology journey of miniaturisation from early large satellite terminals installed on general aviation to the innovative low SWaP-C hybrid UAV terminal being developed with TTP.
Steve Hutt rounded off the talks with a presentation on uAvionix Corporation’s low SWaP-C UAS C2 systems, which demonstrate the benefits of integrating L-band SATCOM, terrestrial C-band, and 4G connectivity. Built on these, the C2 Communication Service Provider (C2CSP) model provides simple access to resilient multi-datalink C2.
The US state of North Dakota, through its Vantis programme, is developing C2CSP infrastructure and business models to offer a “state service” that BVLOS drone operators can subscribe to, instead of each having to buy, build and operate their own dedicated C2 ground infrastructure.
Will BVLOS fly?
Much of the discussion during the day focused on commercial applications and the challenges inconspicuous and uncooperative airspace users present to BVLOS operations.
If not last-mile delivery to your front door – owing to the safety challenges presented by, never mind by aircraft, but by inconspicuous and uncooperative humans – what will be the first commercial use cases for BVLOS?
Another recurring question was: Until fully capable DAA solutions exist and have the backing of regulators, what will be the role of Electronic Conspicuity and airspace licensing in enabling BVLOS?
“If we can unlock regulation to enable BVLOS in time, we could see tens of thousands of commercial drones in markets such as long linear inspection, agriculture, or uncrewed long-distance cargo delivery”, said Vidhya Sridhar, TTP plc’s Autonomous Technology Lead. “That is why it is important for the industry to work with regulators to influence and put in place the right set of enablers.”