Nightingale was our 2025 UAS Challenge aircraft. The team focused on two things: reducing weight and improving aerodynamic efficiency so the aircraft could fly farther.
What changed
- V-tail: The tail layout reduced part count and weight while keeping the control surfaces the aircraft needed.
- Tool-free assembly: Custom clamps and click connections let the wings and tail fit inside the competition crate and go together quickly.
- Carbon-reinforced connections: The 3D-printed joints used carbon-reinforced filament where extra stiffness was needed.
- Smaller fuselage: A 20% reduction in size cut frontal area while leaving room for the electronics, batteries, and 1.5 kg aid package.
Aerodynamics
The aerodynamic work focused on flight at roughly 60 m altitude and 55 km/h. At this scale and speed, the wing operates at a much lower Reynolds number than a commercial aircraft, so airfoil behaviour and surface quality matter differently.
Wings
The team used XFoil and XFLR5 to compare airfoils for lift-to-drag ratio and stall behaviour. The 3.2 m wingspan was the largest that still fit the transport box without adding too much structural weight.
Fuselage
The fuselage was reduced to a compact fairing around the payload and avionics. Less frontal area meant less drag in forward flight.
Airframe
Early PVC frame concepts helped the team compare flexibility and stiffness before committing to the final structure. That frame then had to fit inside the available thickness of the wing profile.
Assembly
The click system lets the team attach the V-tail and wing sections quickly without specialised tools. It was designed around the competition’s assembly-time limit and the loads expected in flight.
Competition Story
One week before the IMechE UAS Challenge, a loose battery caused Nightingale to crash during final testing. The team rebuilt key parts and finished the aircraft after arriving in the UK, with no time left for another test flight.
High winds ruled out a safe attempt on Thursday, so the team waited until the final day. On Friday, Nightingale completed 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 as intended. With seconds to decide, the team chose to keep going rather than land safely. The tether finally snapped, the package released successfully with no damage to the drone, and Nightingale completed a second lap before landing safely just before the battery ran out.
Nightingale finished eighth overall, the team’s best relative placement and the highest VTOL score at the 2025 challenge. It also won the Best Design Award, presented by Leonardo, and Best Media & Engagement for the second year in a row.