Revolutionising mobility in cities through UAVs - the airspace design challenge

The City of Hamburg has been developing Urban Air Mobility (UAM) as a strategic policy since 2017. Its strategy has been a step-by-step implementation of UAM, with an initial focus on Unmanned Aerial Vehicles (UAVs) that are already certified and permitted to fly uncrewed. A special emphasis lies on UAV uses by public authorities or the Port of Hamburg, reflecting its potential as a strategic asset to Hamburg. After all, the city is one of the world’s leading aerospace industry centres and a digital mobility frontrunner. Established in 2017, the UAM network Windrove has become a driving force behind UAV economic development in Hamburg. Windrove supports the regional UAV community with events, networking opportunities and by generating visibility to the wider public. Particularly important is its role in linking policymakers, science and industry. This has led to strong cooperation across different organisations and stakeholders; as a result, public institutions are often project partners alongside commercial operators.

This collaboration has been fundamental to the development of the UAV sector in Hamburg, driving economic growth and providing a foundation for the many small steps Hamburg has taken – and is still taking – on its way towards UAV operations in this urban space that are safe, integrated and trusted by the public.

Mobility is more than traffic. It includes infrastructure, maintenance and intelligent management of vehicles as an integral part of the smart city approach. Cities that are currently making use of UAVs are already benefiting, although the potential has not been fully realised yet.

2019 saw the launch of Medifly. This innovative project delivers a proof-of-concept for an urban delivery service by UAV of urgent medical material. A core component of Medifly is to show the potential social benefits of UAV use, be it by reducing the workload of staff, saving emissions or providing patients with faster care. Even members of the public who are sceptical of UAV use in their urban spaces react positively to medical UAV use. As such, the project team behind Medifly sees it as a first step towards a wider acceptance of civilian UAV missions. The project also involved the healthcare sector as an important supporter of urban UAV operations.

Despite numerous research efforts in using UAVs, one of the biggest challenges in Hamburg is not yet fully resolved, namely the integration of UAVs into dense and complex airspace. With two airports within the city’s boundaries, almost the entire airspace is part of a control zone (CTR). As a result, UAV flights are restricted in some cases. They have to align with the air traffic at the airport, even though they are not technically equipped for this. On the one hand, rules need to be adjusted to accommodate UAVs; on the other, UAVs need to be coordinated with general or crewed air traffic when they fly in a CTR to ensure safety.

This dilemma drove Hamburg to take on a major challenge: the design of airspace for UAVs. Enter UDVeo (“Urban Drone Traffic efficiently organised”), a pioneer project launched in 2020 before the European regulatory framework for a European coordination system for uncrewed traffic (U-space) went into effect in April 2021. The project developed an interdisciplinary approach to implement U-space regulation, added legal proposals and developed the first U-space systems. A successful cooperation between research institutes, industry and public policymakers laid the groundwork for two U-space projects in Hamburg run by consortia with a similarly broad make-up, both funded by the federal government. The first project ran for one year and examined the legal and technical challenges of U-spaces, while also tackling the issue of promoting public acceptance and enabling competition in a U-space. The second project ran for six months and tested some UAV use cases in the Port of Hamburg over a period of three months, in the first ever European U-space sandbox.

The main reason for this seems to be that the European Commission's legislation on the framework of a U-space is an important step but is only halfway to enabling the coordination of commercial UAV traffic. To complete it, the technical set-up of the new U-space system has to make the transition from a model into a real-world system. But the infrastructure set-up of a U-space is a complex undertaking. In a U-space, all required information for the UAV remote pilot has to be collected by the appropriate stakeholder. In particular, official agencies such as police, fire departments, or the air traffic control centre must format data in such a way that it can be immediately sent to the remote pilot via a digital interface. They must also have the necessary technology in place, if necessary by customised existing equipment or developing new equipment along the way. In addition, airspace management companies (U-space Service Providers) must develop a new system that can receive this information in real time and present it to the UAV remote pilot through an operator-friendly application. In order to guarantee the reservation of flight spaces in advance, these companies need to programme a coordination platform.

All in all, the new U-space systems generate and distribute information, requiring testing beforehand to prove their reliability and practicability. This becomes especially important when different and new stakeholders, both private and public, are connected. The entire management system can only work if all systems function in a stable way. If even a part of the required information is missing, the security of the system may suffer.

Hamburg has a response to this big challenge. In December 2023, the fourth interdisciplinary U-space project started in Hamburg, running for two-and-a- half years. It is funded by the federal government and aims to link the necessary U-space systems for the first time under real conditions, developing cross-interface blueprints and involving a broad section of the UAV economy.

Hamburg’s planners understand that airspace integration is not only a question of organisational structures and technology development. Just as important from a city perspective is public acceptance. The case of e-scooters banned from Paris shows that new types of mobility entering a crowded traffic system succeeds only with wide acceptance in the population. Air mobility is far more complex than ground-based mobility. The wider public are not the only people who will take some convincing; many more stakeholders need to be persuaded to share the crowded airspace and open the system to new actors. Among others, this could include helicopter emergency services, environmental organisations and city administrations, including city developers.

Another key aspect of Hamburg’s approach is to pursue a participatory approach to get all relevant stakeholders on board. Concurrently with the living lab project, Hamburg is launching a community-driven UAM strategy process in the first half of 2024.

City and business leaders are proud of Hamburg’s status as a leading UAV pioneer. However, the biggest challenges – U-space operational implementation and societal integration – are yet to come. Successful U-space management will deliver both flight safety and planning reliability for UAV operators, two decisive factors in making UAV traffic scalable. A prerequisite for this is that cities are included in the process and become active themselves, because as a new form of mobility UAV traffic will affect cityscapes across Europe. That makes it crucial that the EU and its Member States involve cities along the way to achieve harmonised European-wide UAV traffic.