Zephyros is our 2026 fixed-wing VTOL tricopter for autonomous humanitarian aid missions. The name comes from Zephyrus, the Greek god of the west wind.
Three motors, two modes of flight
Two front motors tilt between vertical and forward flight, while a third motor completes the tricopter layout. Changing the thrust direction of the front motors also controls yaw, so the aircraft does not need another propulsion unit.
Carbon structure
For the first time, the team manufactured its own carbon-fibre tubes. The prepreg tubes cure at 100°C and form part of a frame weighing just under one kilogram.
Autonomous systems
The flight stack uses a Pixhawk controller running ArduPilot, with Mission Planner for setup and mission control. LiDAR and airspeed sensors provide data for autonomous take-off, transition, payload delivery, and landing.
Aerodynamics and propulsion
The wing uses a CH10 airfoil with a lifting-body fuselage and V-tail. Ground tests measured up to 7.9 kg of thrust per motor. The motors carry the aircraft vertically, then the wing takes over in cruise.
Humanitarian payload
Zephyros carries a custom water tank with internal baffles, a wax-treated waterproof shell, and a servo-operated valve. It can release three litres of water in under 3.5 seconds. The team also developed a solar-wing concept that could recharge the 12-cell battery system in about 2 hours and 45 minutes in sunny conditions.
Competition result
At the 2026 IMechE UAS Challenge, Drone Team Twente received the Rebuild Award and recorded a total score of 356 points.