Madrid, España / La Selva Beach, California. Parallel Flight Technologies, Inc., a developer of next-generation unmanned aircraft systems, and Alpha Unmanned Systems, a European leader in fuel-powered helicopter UAVs, February 11 announced a collaboration to advance heavy-fuel propulsion technologies for unmanned aviation in support of the US Office of Naval Research (ONR).
Under an ONR programme, Parallel Flight is adapting its Firefly UAS to operate on heavy fuel, enabling long-endurance, heavy-lift unmanned aircraft capable of sustained operations in demanding naval and expeditionary environments. The contract builds on Firefly’s exceptional hybrid electric architecture and is designed to extend Firefly’s operational reach into maritime and other mission profiles requiring aviation-grade fuel.
“We are very pleased to work with Alpha Unmanned Systems,” said Craig Stevens, CEO of Parallel Flight Technologies. “Alpha’s real-world experience with heavy-fuel propulsion has been directly applicable to our development objectives, helping us refine and validate our hybrid architecture to meet the unique demands of naval and expeditionary missions.”
Alpha Unmanned Systems brings more than a decade of expertise in designing, integrating, and operating heavy-fuel helicopter UAVs for defence, maritime, and security applications. Working closely with Parallel Flight’s engineering team, Alpha is helping accelerate the conversion of Parallel Flight’s proprietary Parallel Hybrid Electric Multirotor (PHEM) propulsion systems to heavy-fuel compatibility, a key enabler for fielding unmanned aircraft that align with existing military logistics and fuel infrastructures.
“The use of heavy-fuel engines is essential for unmanned aircraft deployed in challenging defence and maritime operating environments,” said Álvaro Escarpenter, CTO of Alpha Unmanned Systems. “We are proud to support Parallel Flight’s efforts and contribute our expertise in heavy-fuel UAV propulsion to this important programme.”
Parallel Flight’s NDAA-compliant Firefly is a Group 3 UAS, produced in the USA and widely regarded as a heavy-lift workhorse. A two-person-portable quadcopter that fits in the back of a pickup truck, Firefly is optimised for expeditionary defence and industrial missions. Its patented Parallel Hybrid Electric Multirotor (PHEM) propulsion system enables payloads up to 100 lb (45kg) and endurance 10x greater than all-electric UAS, while also supplying 2 kW of continuous in-flight power to payloads. The platform is protected by five patents and supported by DIU, USDA, NASA, and NSF.
The collaboration reflects a shared focus on propulsion technologies that enhance operational flexibility, reduce logistical burden, and improve safety and endurance for unmanned systems operating in austere and high-tempo environments.
