UK regulators have set out the steps needed to open the country’s airspace for widespread operation of uncrewed air systems (UAS) by 2027 to “maximise [their] economic and social benefits”.
In its latest policy document, the Civil Aviation Authority (CAA) identifies the key regulatory changes and technologies required to enable beyond visual line of sight (BVLOS) operation of UAS to be “a routine part of aviation – ‘business as usual’ – across the UK”, it says.
Tests of BVLOS operations have to date been conducted in segregated airspace “due to the unmitigated risk of mid-air collision with other aircraft”.
That airspace is typically provided through the establishment of a ‘temporary danger area’ (TDA) – blocks of restricted airspace in place for no more than 90 days – but these are not a “practical long-term solution for a sustainable BVLOS business model” due to their inherent limitations, the CAA says.
Safety remains the priority, the agency says, so that “all airspace users are sufficiently protected, and the risk to people and property on the ground is reduced to acceptable levels”.
It sees the requirement for a “technical and operational solution” using detect-and-avoid (DAA) technologies to remove the need for TDAs and to enable “UAS operations within airspace that is safely shared with other aircraft”.
Taking a “technology-agnostic approach”, it sees the solution as a “combination of several components that are interoperable”, including: electronic conspicuity via ADS-B, an “assured” remote pilot station, robust command and control links, and DAA capabilities.
The DAA technology, it notes, “should be a capability that is at least equivalent to the ‘see-and-avoid’ principle used in manned aviation to avoid collision with other aircraft and obstacles”.
On top of which an air traffic management (ATM) system should be implemented in low-level airspace that includes “specific services for UAS as well as other value-added services for existing airspace users and other new vehicles such as electric vertical take-off and landing (eVTOL) aircraft”.
Operations in urban environments “where ground risk must be recognised and mitigated”, presents a further challenge, the CAA adds.
Overall, the changes to permit BVLOS operations are “intrinsically interconnected with and dependent on” the UK’s airspace modernisation strategy, the document adds.
“The CAA is already working with operators, aerospace industry, training organisations and service providers to enable them to develop multiple ways of solving each one of these technical challenges, and we welcome their innovation.”
It sees four primary workstreams: operational authorisations, vehicle flightworthiness, pilot competency, and airspace integration, all built on “foundation elements” of environmental impact, safety, physical security, and cybersecurity.
Vehicle flightworthiness “needs to be assessed and validated to form a part of the mitigation for ground risk”, it says, adding: “This assessment will review evidence relating to the design, build and testing of the UAS, helping to ensure that it is safe to fly the proposed operation.”
Under the Specific Operation Risk Assessment to be adopted by the CAA from 2025, features, particularly a robust DAA system, will allow a vehicle to access significantly larger amounts of airspace.
Pilot training will also be a key component, it adds; the CAA is proposing to introduce two new certification levels “to support a wider range of future operational scenarios”. Additionally, it proposes that in the initial phase of widespread BVLOS operations, one remote pilot controls only one UAS.
The CAA’s roadmap runs through three phases: demonstrate, scale, sustain.
Initial demonstration efforts are scheduled to commence this year and “will inform how the operations can be extended to enable routine operations by 2027.”
A glimpse into how successful airspace integration might look, and the hurdles to overcome, has been provided by a project called ALIAS – agile and integrated airspace system – carried out under the UK’s Future Flight Challenge programme.
Led by Volant Autonomy – a University of Bath spin-out – and running from 2022, the £3.7 million ($4.9 million) project culminated earlier this summer with a series of flight trials in Jersey in the Channel Islands.
“The overall objective of the project was to design, develop and demonstrate a viable integrated traffic management [ITM] system where crewed and uncrewed aircraft could operate in the same airspace, under the same operating principles.”
During the tests, a pair of SkyLift V-23 vertical take-off and landing fixed-wing UASs were flown from Jersey’s airport to demonstrate integration with existing airspace infrastructure.
In addition, ALIAS used a Diamond Aircraft DA-42 supplied by Draken Europe to test the interaction of crewed and uncrewed assets within the ITM system. Aircraft were equipped with Volant’s Traject ACAS sXu DAA system for the trials.
“The live crewed-uncrewed DAA demonstrated how new technologies can be adopted into the exiting airspace system under existing and exacting standards of assurance,” says Volant, noting that the testing is “believed to be the first of its kind in Europe”.
“Volant took up this challenge to develop a prototype ITM which was designed to demonstrate how, by adapting uncrewed technologies to existing airspace principles, commercial uncrewed operations are both viable and scalable,” it adds.
“Developing an ITM system is not just about adopting new technology and new regulations, but is as much about learning to operationally deploy new capabilities in order to solve real-world problems.”
