Use Cases

DAEDALUS validates altitude-enhanced airspace layering through six representative use cases. Each one places a drone in a realistic very-low-level (VLL) situation — sharing airspace with another drone, with crewed aviation, or facing a sudden loss of navigation quality — and shows how the system keeps flights safely separated in the vertical dimension without closing the airspace down.

Three building blocks recur across every case. The Common Altitude Reference System (CARS) gives every airspace user a shared, unambiguous way to express altitude. The Dynamic Airspace Layering (DAL) engine turns that common reference into assigned vertical layers and a vertical separation minimum (VSM) — the buffer that must sit between users — derived from an explicit Target Level of Safety. When navigation accuracy or conformance degrades, DAL widens that buffer in real time to hold the safety target. The use cases below show these mechanisms at work.

Use Case 1 — Layering with a specific altitude need

Two drones operated by different operators need to cross the same volume. One of them — an inspection flight — has a firm altitude requirement: it must hold a precise height above the surface to do its job. The other is free to fly higher or lower. Without coordination, their paths conflict in the vertical plane.

This is the everyday case for mixed drone traffic where one user cannot move and the other can.

DAEDALUS resolves the conflict at authorisation time. DAL respects the inspection drone's altitude need and assigns the second operator a separate vertical layer above it, applying the required VSM between them. Both operators keep flying their missions; the system simply tells each one which layer to occupy and notifies them of the resulting airspace structure.

Use Case 2 — Layering with no specific altitude need

Now both operators are flying point-to-point deliveries, and neither has a particular altitude requirement — they just need to get from A to B. The vertical dimension is fully available to optimise.

This is the high-capacity case: many flexible flights wanting to share a finite volume efficiently.

Because neither operator is constrained, DAL is free to assign optimal layers to both, maximising how many flights the volume can hold while keeping the VSM between them. The result is more throughput from the same airspace, with conflicts resolved before either drone takes off.

Use Case 3 — Shared airspace with commercial aviation

A drone operates in a volume that also sees commercial air traffic above it. Crewed aviation references its altitude barometrically (QNH); the drone references its altitude geometrically. The two systems describe height in fundamentally different ways, so "safe separation" is only meaningful once those references are reconciled.

This is the interoperability case — where U-space has to speak the same vertical language as traditional ATM.

DAEDALUS uses CARS to convert between barometric and geometric references, so DAL can compute a vertical separation that is valid for both worlds and assign the drone a layer safely clear of the crewed traffic. Interoperability with ATC is exercised through the CIS interface, ensuring the separation holds across both domains.

Use Case 4 — Drones and General Aviation near the U-space ceiling

A VFR General Aviation aircraft is flying just above the U-space ceiling — typically around 500 ft, though a State may declare a higher limit — while a drone operates just below it. The vertical gap between them is small and the GA aircraft is not part of the U-space system, so the drone has to give way.

This is the edge case at the top of VLL airspace, where uncontrolled crewed traffic and drones come closest.

DAL calculates the vertical buffer the drone must keep below the ceiling and assigns its authorisation accordingly, holding a safe distance beneath crewed aircraft. The drone descends into its assigned layer to pass clear, then is free to resume — separation maintained without relying on the GA pilot to act.

Use Case 5 — Recalculation under GNSS degradation

A drone is flying within its nominal layer when the infrastructure monitoring service detects GNSS signal degradation — jamming, spoofing, or a natural loss of accuracy. The drone's ability to hold its declared altitude has just become less trustworthy, so the separation that was safe a moment ago may no longer be enough.

This is the resilience case: safety has to degrade gracefully, not cliff-edge, when navigation quality drops.

On the alert, DAL recalculates the separation minima and widens the buffer from its nominal value to an increased VSM that accounts for the larger position uncertainty. Tactical deconfliction maintains safety throughout, and the buffer returns to nominal once integrity is restored — the airspace tightens and loosens with the actual navigation performance.

Use Case 6 — Recalculation on loss of vertical conformance

Here the trigger is behavioural rather than environmental: the USSP's conformance monitoring service detects that a drone has drifted out of its assigned vertical layer. The navigation signal is fine, but the aircraft is no longer where the authorisation said it would be.

This is the conformance case — the system responding to a flight that has stopped matching its plan.

DAEDALUS treats the deviation as a live risk and has DAL widen the VSM around the affected flight, expanding the buffer from nominal to increased until the situation is corrected. Conformance monitoring and the corrective layer assignment work together to contain the deviation before it becomes a conflict.