Hex Appeal

Sikorsky, the storied rotorcraft builder and Lockheed-Martin subsidiary, announced on 14 March 2023 that it is building a fully autonomous hybrid-eVTOL which will serve as a flying testbed by dint of which the company will evaluate new designs and vet novel propulsion systems for future, longer-range aircraft.

The hybrid-electric demonstrator, to be ascribed the delightfully pagan moniker Hex, will have an ample maximum gross weight of seven-thousand-pounds (3,175-kilograms). The unmanned contraption will be used, also, to test flight-control architectures conducive to sustained hover and mission ranges greater than five-hundred-nautical-miles (925-kilometers).

The turboshaft engine by which Hex is to be powered is GE Aerospace’s 1,625-shaft-horsepower CT7. GE Aerospace will also supply the machine’s one-megawatt (1MW) class generator and associated drivetrain electronics. An inveterate developer of hybrid-electric technologies, GE Aerospace has previously built similar propulsion systems for NASA and the U.S. Army.

Sikorsky president Paul Lemmo stated: “Sikorsky’s Hex aircraft will provide critical insights into the possibilities of electric systems in VTOL aircraft. Ultimately, we want to show the potential of large, advanced air mobility vehicles to perform utility missions for the US military and transport passengers between cities.”

GE Aerospace president and CEO of defense and systems Amy Gowder remarked: “Bringing innovative technology is a top priority for GE Aerospace. We are committed to developing hybrid electric propulsion systems that save fuel and optimize performance for the military and commercial applications. We are thrilled to build off our existing work with NASA and the Army to offer to power Sikorsky’s Hex aircraft and bolster the future of flight.”

The Hex program will be spear-headed by the Sikorsky Innovations rapid prototyping group and its director, Igor Cherepinsky. Sikorsky’s Innovations team will design, build, and integrate the HEX airframe and electric motors with the company’s Matrix autonomous flight control system. Subject system, which will control the Hex aircraft in flight, has been developed and tested over the past decade in low-altitude and obstacle-rich scenarios.

During the U.S. Army’s 2022 Project Convergence exercise, an unmanned, Matrix-controlled Black Hawk helicopter successfully demonstrated optionally-piloted resupply missions.

Sikorsky believes the Hex program could engender a family of eVTOL vehicles scaled to carry passengers and payloads in both military and commercial operations.

FMI: www.lockheedmartin.com/en-us/capabilities/sikorsky.html