Ukraine has begun operational testing of a hydrogen-electric version of the Raybird reconnaissance UAV, developed by local firm Skyeton and reportedly flown in active combat conditions. Rather than chasing maximum endurance, the hydrogen Raybird prioritises reduced acoustic and thermal signatures, using fuel cells to generate electricity for quiet electric propulsion. With an endurance currently stated at around 12 hours, a service ceiling near 5,500 metres, and modular ISR payloads, the platform is positioned for deep surveillance missions in contested airspace where detectability matters as much as range. While hydrogen drones are not new in concept, Skyeton’s claim centres on real-world combat use, raising questions about scalability, logistics, and whether hydrogen propulsion can move beyond niche roles in wartime UAV operations.