This call topic supports the development of autonomous and automatic air-to-air refuelling (A4R) capabilities to improve the endurance, reach, and efficiency of European military air operations, including operations in remote areas. Today, air-to-air refuelling is performed manually by tanker operators and receiver pilots, which imposes high workload and introduces operational constraints. While automatic A4R can already reduce crew workload and increase safety, the next step—autonomous A4R—is expected to be crucial for aerial refuelling of future manned and unmanned aircraft.

The call focuses on exploring and adapting new and existing technologies up to TRL 6, with a strong emphasis on sensor systems, sensor fusion, and interfaces that enable accurate relative navigation between the tanker, one or more receiver aircraft (manned or unmanned), and the refuelling system (probe and drogue), even in adverse conditions. Applicants are expected to analyse the maturity of relevant technologies and identify key challenges—particularly in hardware integration and sensor fusion—while also advancing improved optical sensors, advanced image processing, flight control algorithms, and supervision interfaces to increase docking/refuelling safety and time efficiency.

Proposals must address core elements such as: autonomous receiver autopilot functions for current and future manned fighter aircraft and unmanned receivers (including representative simulation models to support future integration); integration of sensor technologies, sensor fusion, and data exchange interfaces for precise relative navigation; and development of an autonomous A4R concept of operations (CONOPS) where a strategic tanker refuels multiple manned and unmanned receivers. A standardisation outline proposal for autonomous A4R is required, alongside demonstration of the technology in a flight test including at least a dry contact to enable data gathering for the technologies studied and designed.

Beyond the mandatory elements, proposals should cover tanker/receiver communication, data link and telemetry requirements for autonomous A4R, and further demonstrations including wet contact to verify study results and validate key technology designs. Demonstration of a visual tracking and processing system enabling the receiver to perform autonomous A4R operations in line with the CONOPS is also expected. Navigation sensor fusion for relative position algorithms may be included. Importantly, proposals must not address boom technology, as it is explicitly outside the topic’s scope.

The call defines eligible activity types and sets mandatory work across “integrating knowledge”, “studies”, and “design”, including: defining CONOPS for interoperability; integrating sensor systems for relative navigation in adverse conditions (including EMCON); assessing optical sensors (camera, laser) and image processing; producing a technical and functional evolutionary roadmap for autonomy improvements in tanker/receiver aircraft; and designing flight control modes/algorithms, crew interfaces/assistance and actively controlled/stabilised refuelling systems (drogue). For unmanned receivers, the design must include higher-level mission management for fully autonomous A4R including three or more aircraft, supported by test environments/procedures such as laboratory component tests, integrated simulator tests, and sub-scale and full-scale flight tests.

Expected contributions include improved reliability and safety, faster and more efficient refuelling operations, reduced crew workload and mission cancellations, and stronger standardisation and interoperability enabling manned–unmanned teaming in future air operations.

Opening: 09.12.2025
Deadline(s): 29.09.2026