Autonomous flight technology start-up Merlin says it has launched flight testing on its proprietary pilot system, using a Boeing KC-135 tanker.

The Boston-based company on 16 August said it has completed three sorties aboard a US Air National Guard Stratotanker in Pittsburgh, Pennsylvania, with the first flight taking place on 22 July.

USAF KC-135

Source: US Air Force

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

Those flights were made under an agreement with the US Air Force (USAF) Air Mobility Command to design, integrate, test and demonstrate aspects of the system, known as Merlin Pilot, on the KC-135. The initial sorties served as an opportunity for Merlin to collect data on system integration and flight control tuning, the company says.

“We’ve achieved important milestones on the KC-135 that allow us to strengthen the relationship between the pilot and the aircraft as well as enhance safety and operational efficiency aboard a vital military aircraft,” says Matt George, founder and chief executive at Merlin.

Merlin hopes to complete an in-flight demonstration of Merlin Pilot aboard a KC-135 sometime in 2025.

In February, Merlin told FlightGlobal the eventual flight demonstrations would include basic refuelling operations. The programme will help inform the USAF’s planned Next Generation Air-refuelling System, and comes amid the service’s broad push for rapid development of autonomous flight technologies.

Separately, Merlin is also exploring aircrew reduction technologies for the Lockheed Martin MC-130J special mission transport in conjunction with US Special Operations Command.

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.

In addition to the KC-135, Merlin Pilot has also been equipped in the Beechcraft King Air, De Havilland Canada Twin Otter, Cessna Caravan, Rutan Long-EZ and Cozy Mark IV.

Additional reporting by Howard Hardee