Funding spurs next test stages for Natilus Kona and Heart ES-36

The US Air Force's energy office is paying Natilus to take the Kona freighter towards full-scale flight testing, and the FAA's lower-energy programme is funding Heart's ES-36 turbogenerator tests.

The US Air Force has awarded Natilus $3.5 million in research, development, test and evaluation funding to take its Kona blended-wing-body freighter towards full-scale flight testing and an operationally relevant Joint Force demonstration. The money comes from Operational Energy Innovation and from the Department of the Air Force through the Assistant Secretary of the Air Force for Energy, Installations and Environment. Meanwhile, the FAA selected Heart Aerospace for a $2.9 million award under Phase IV of its Continuous Lower Energy, Emissions and Noise programme, to develop and test the turbogenerator for the ES-36 series-hybrid propulsion system. An Air Force energy office and the FAA's lower-energy technology programme are now paying for the next test stages of two aircraft built around configurations that have not yet flown at full scale.

Kona is a 3.8-ton, optionally piloted regional freighter with an 800-nautical-mile range and short-field capability. Natilus places it between the C-208 and the C-130 as a new class of sub-tactical lift, and ties the military case to the Indo-Pacific, where it says distances, distributed operating locations and constrained fuel logistics put a premium on range and efficiency. That is an energy argument, and both named funders carry energy in their titles: Operational Energy Innovation, and the Assistant Secretary of the Air Force for Energy, Installations and Environment. The award itself is development money for flight testing and a Joint Force demonstration of a design whose efficiency case Natilus rests on the blended-wing-body configuration.

Heart's award carries an equal cost share from the company, making Project HYPER a $5.8 million, 24-month R&D and demonstration project. Each of the ES-36's two nacelles is to house a megawatt-class turbogenerator producing electricity in flight, extending range beyond what the batteries alone provide. The work starts with ground testing of how the turbogenerator, batteries and electric motors behave together in different operating modes, before progressing to the pre-production aircraft, which is scheduled to make its first flight in 2028. The CLEEN money therefore funds the hybrid element of the design, the part that distinguishes the ES-36 from the battery-powered X1 demonstrator whose flight we reported in August.