UTM: Ordered skies without clipped wings
The drone industry is at a crossroads. The technology is moving rapidly from the realm of blue sky thinking to the sky above our heads, but managing this transition safely without stifling innovation is proving challenging.
At present there is no system to manage the widespread use of drones, or Unmanned Aircraft System (UAS), in low-altitude airspace below 150m (500ft) where most commercial applications are expected to play out. Traditional air traffic management (ATM) approaches aren’t feasible because they rely on constant communication with human pilots and radar detection, which struggles with small drones.
This has led to calls for UAS Traffic Management (UTM) solutions to deal with the safety, security and privacy issues entailed by the predicted explosion in airspace users. The term was coined by NASA, which has taken an undeniable lead in the field by creating a UTM research consortium of government agencies and major tech companies. But the idea is loosely defined and there is considerably uncertainty on what a fully-fledged UTM system would look like.
“UTM is still a fuzzy concept,” says Simon Johnson, curator of the UTM Day. “We wanted to create a forum for both the incumbent air traffic management community and the drone community to exchange ideas that should not only help clarify exactly what UTM means in a European context, but also let us set priorities and the groundwork for pragmatic rules.”
There is broad agreement on the central requirements of a UTM system – accurate and reliable drone tracking; solid two-way communication between UAS and the system; and access to real-time information on things like flight-planning, flight authorisation and weather. Fast and simple airspace design is also a must, so that controllers can quickly set up geofences – virtual barriers that prevent drones from entering a specified area – or re-route traffic. Most envisage a system with far more automation than current ATM, with computers determining collision-free trajectories and optimising traffic flow. Human controllers will only intervene to make strategic decisions or in emergencies.
Mobile networks appear to be in pole position to provide the backbone of future UTM. Combined with on-board GPS the technology could allow accurate and low-latency tracking and communication. Importantly the infrastructure is already in place, says Nokia’s Sebastian Babiarz, and drones constantly connected to the internet over high-bandwidth 3G and 4G networks could unlock countless novel applications.
While current networks were not built with drones in mind, Babiarz notes that future 5G standards are being specifically designed to accommodate UAS. Mobile network providers are working on Low Power Wide Area Networks that could help address concerns over gaps in coverage, but Tyler Collins, vice president of PrecisionHawk’s LATAS UTM solution, believes UTM designers can learn from traditional ATM.
“Planes go in and out of radar coverage, but there are associated risk levels with those areas and procedures in place to have fairly good idea where that aircraft is,” he says. “Based on the area, based on the risk it may not always be necessary to have 100% coverage.” As drones become increasingly automated, pre-defined flight plans will make this even easier, he adds.
Most drone operators are not aviators though, so making sure critical information reaches operators is no use unless it is easily digestible by non-experts. “Giving complex information in a format they can understand in a few seconds, that’s the key and it will drive the market,” says Marc Kegelaers, CEO at Belgium UTM start-up UniFly.
But while the technical challenges of implementing UTM are considerable, the bigger question is how to integrate it with current approaches to airspace management. The ATM community is highly conservative and safety-focused, says Muriel Preux, Remotely Piloted Aircraft System (RPAS) programme manager for France’s Directorate General for Civil Aviation, the polar opposite of the innovative drone industry. “The main problem today is to merge the aviation industry culture and the drone culture,” she says. “We have to find a balance between safety and innovation.”
There is broad agreement that drones operating in controlled airspace will be subject to the same rules as manned aircraft, but Preux says regulators must be pragmatic about what does and does not need to be managed. Rural operations are unlikely to need the same level of control as package delivery drones in cities and until higher traffic applications become a reality a light touch may be wise. “As far as we’re concerned, if the traffic is not too high the rules can be less stringent,” she adds.
ATM is already struggling to deal with current levels of traffic, says Andrew Charlton, managing director of consultants Aviation Advocacy, so applying traditional approaches to drones is neither feasible nor desirable. “The worst possible outcome is air traffic control for the currently uncontrolled airspace. We want to bring order and discipline but we don’t want control,” he says. “It isn’t an opportunity to make drones behave like manned aircraft.”
Francis Schubert, deputy CEO at skyguide the Swiss air navigation service provider (ANSP), agrees. “This is the biggest risk – setting up a UTM trying to emulate the infrastructure system you have in the classical ATM system,” he says. Despite that, the drone community can learn from the ATM community’s experience in designing robust safety management processes. Similarly, ATM can tap into the innovation of UTM, particularly in regards to automation. “It can serve as a lab to test processes, tools and functions that can’t be developed easily in the classical ATM world,” says Schubert.
The tension between the ATM and drone communities also raises the question of who will be responsible for implementing future UTM. New technology brings with it opportunities for innovative new models for regulating airspace. Mobile networks could not only provide the backbone of future UTM, but also a blueprint for their operation, says UTM Day’s Johnson. Just as a mobile phone owner chooses their network provider, drone operators could choose from a range of UTM providers competing on cost and services.
A common architecture and regulations could allow these providers to coordinate with each other and traditional ATM in a federated way, says Charlton, allowing seamless integration without hierarchy. Craig Marcinkowski, who is leading Gryphon Sensors work on UTM as part of the NASA consortium, thinks some kind of multiple provider model is likely to prevail in the US, with the Federal Aviation Authority (FAA) likely to support performance based standards that would allow multiple UTM providers. “That would be a nice competitive, open approach to allow people to bring solutions to market,” he adds.
However, skyguide’s Schubert says the enthusiasm of the drone community may come up against the two guiding principles of European aviation – sovereignty and safety. He thinks governments will want a core UTM provider at the heart of the system to reduce interfaces with the legacy ATM system, though he does see many functions of a UTM being delegated to third parties. In Europe almost all ANSPs design, produce and implement their own systems, a model Schubert says belongs to past. As a test case skyguide is trying to change Swiss law so they can get their flight data services from a third party provider. The move is not motivated by considerations of drone integration, but he says it could well serve as a model for future UTM.
PrecisionHawk’s Collins agrees the core of a UTM system is likely to be centralised, but he thinks a plurality of UTM service providers feeding into this will be essential – a delivery company will have very different needs to a precision agriculture firm. UTM firms need to find their niche today though, he says. “You need a product that can be developed towards a UTM system, but serves a market today so that the company can go out and start growing,” he says.
Central to what shape UTM services take will be the jurisdiction they are responsible for. Work to harmonise ATM across Europe has been ongoing for some time, but progress has been slow. Some see the blank page of UTM regulations as an opportunity to bypass the headache of synchronising approaches after the fact. The European Aviation Safety Agency (EASA) has already started the process of coming up with UTM guidelines and Aviation Advocacy’s Charlton believes there should be a concerted push for a pan-European solution before national regulators diverge. He thinks EASA’s proposals look solid and believes the process could see results in as little as two years.
Schubert agrees the proposals appear well-thought-out, in particular the suggestion of three risk-based categories of drones with different levels of management. “But Europe being what it is, it’s going to take longer,” he says. EASA and the Single European Sky ATM Research project are making efforts to tackle the problem, but he thinks a five to ten year horizon is more likely.
In the meantime national regulators are likely to push ahead with their own solutions, he says, and harmonisation will happen further down the line. According to Nokia’s Babiarz, this is no bad thing. “Each country can take a different initiative. That makes getting started easier and when one has success the other countries can copy,” he says.
Taking this kind of fragmented approach to UTM development does have its downsides though. NASA’s well-funded and collaborative approach to the problem, led by the charismatic Parimal Kopardeker and backed by some of the country’s most influential tech firms, threatens to leave Europe’s efforts to shape the future of UTM in the dust.
Whether that matters or not is up for debate. “If the NASA approach appears to make sense then hopefully the model could be exported to other countries,” says skyguide’s Schubert. “At the moment there’s no indication their design doesn’t make sense.” But surrendering the chance to influence the design of a future piece of critical infrastructure could turn out to be short-sighted, particularly when much of the prevarication is motivated by safety and security concerns.