Autonomous flight technology company Merlin has an agreement with the US Air Force (USAF) to work toward uncrewed operations of the Boeing KC-135 Stratotanker. 

Merlin disclosed on 13 February that it will “design, integrate, test and demonstrate” aspects of its “Merlin Pilot” system on the KC-135, with plans to conduct flight demonstrations within the year. 

The Boston-based start-up describes the multi-year partnership with Air Mobility Command and Air Force Materiel Command as “a stepwise approach, starting with reducing crew workload, then proceeding to reduced-crew operations”. 

“As the system gains experience and trust, it will pave the way for autonomous uncrewed operations of the KC-135,” Merlin says. 

USAF KC-135

Source: US Air Force

The USAF still operates 378 KC-135s, the oldest of which first flew in 1957

An upcoming series of flight demonstrations conducted with the USAF will include basic refuelling operations, Merlin says. The programme will inform the service’s planned Next Generation Air-refuelling System, and comes amid the USAF’s broad push for rapid development of autonomous flight technologies. 

Merlin did not indicate where the demonstrations would take place. 

“Integrating onto one of the most abundant and important military aircraft in the USAF’s fleet allows Merlin to materially evolve our advanced automation systems, which includes enabling autonomous close formation flying for the KC-135,” says Matt George, Merlin’s co-founder and chief executive. 

Air Mobility Command manages a fleet of nearly 400 KC-135s. Efforts are underway to modernise and replace the USAF’s ageing air tankers, which average more than 60 years old, according to Cirium fleets data. 

But a requirement included in the 2024 defence spending bill prevents the retirement of any KC-135s and bars the USAF from deciding on how to replace the ageing refueller – until it produces a plan to procure a next-generation stealth tanker. 

The KC-135 would be the sixth aircraft to be equipped with Merlin Pilot, along with the Beechcraft King Air, De Havilland Canada Twin Otter, Cessna Caravan, Rutan Long-EZ and Cozy Mark IV.

Last year, Merlin conducted a flight-test programme in Alaska in collaboration with Everts Air Cargo and the University of Alaska Fairbanks, which operates an uncrewed aircraft systems test site. 

The programme involved autonomous flights from Fairbanks to Fort Yukon, Galena, Prudhoe Bay, Huslia and Tanana, with pilots on board to monitor the experimental flight-control system. 

Merlin is developing autonomous flight technologies along with competitors Reliable Robotics and Xwing, a pair of California Bay Area start-ups that have also been involved in recent flight-testing with the USAF.