Nightingale was our 2025 aircraft. The team had two goals: cut weight, and improve the aerodynamics so it could fly further.
What changed
- A V-tail, which needs fewer parts and weighs less but keeps the control surfaces the aircraft needs.
- Tool-free assembly. Custom clamps and click connectors let the wings and tail fit in the competition crate and go together quickly.
- Carbon-reinforced filament for the printed joints that needed extra stiffness.
- A fuselage 20% smaller, with less frontal area but still room for the electronics, the batteries and the 1.5 kg aid package.
Aerodynamics
We designed for flight at about 60 m altitude and 55 km/h. At that size and speed the wing works at a much lower Reynolds number than a full-size aircraft, so airfoil behaviour and surface finish matter in different ways.
Wings
We used XFoil and XFLR5 to compare airfoils on lift-to-drag ratio and stall behaviour. The 3.2 m span was the biggest that still fit the transport box without adding too much structural weight.
Fuselage
The fuselage shrank to a compact fairing around the payload and the avionics. Less frontal area means less drag in cruise.
Airframe
Before committing to the final structure, the team built early PVC frame concepts to compare flexibility and stiffness. The frame then had to fit inside the thickness of the wing profile.
Assembly
The click system lets us attach the V-tail and wing sections quickly without special tools. It was designed around the competition’s assembly time limit and the loads in flight.
The competition
A week before the IMechE UAS Challenge, a loose battery caused Nightingale to crash in final testing. The team rebuilt the damaged parts and finished the aircraft after arriving in the UK, with no time left for another test flight.
High winds on Thursday ruled out a safe attempt, so we waited for the last day. On Friday Nightingale flew Drone Team Twente’s first full autonomous flight at the UAS Challenge: take-off, transition and a complete lap.
During the package release the tether didn’t snap like it was supposed to. We had seconds to decide, and kept flying instead of landing. The tether did snap, the package came down without damaging the drone, and Nightingale flew a second lap before landing just before the battery ran out.
It finished eighth overall, our best relative result, with the highest VTOL score of the 2025 challenge. It also won the Best Design Award, presented by Leonardo, and Best Media & Engagement for the second year in a row.