Sikorsky is producing HEX, a hybrid-electric demonstrator of a fully-autonomous hybrid-electric vertical-take-off-and-landing (eVTOL) prototype. With a maximum gross weight of more than 7,000-pounds, the uncrewed aircraft will serve as a flying test-bed to evaluate large aircraft design, novel propulsion systems and control architectures for sustained hover and ranges greater than 500 nm.

“As Sikorsky celebrates 100 years of flight innovations, it's fitting to highlight our continued commitment to safe and sustainable transformative flight,” says company president Paul Lemmo. “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.”

For the HEX project, GE Aerospace will offer a CT7 turboshaft engine combined with a 1MW-class generator and associated power electronics, building on hybrid electric propulsion systems being developed by GE Aerospace for both NASA and the US Army.

“Bringing innovative technology is a top priority for GE Aerospace,” notes Amy Gowder, president and CEO of defence and systems at GE Aerospace. “We are committed to developing hybrid electric propulsion systems that save fuel and optimise 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 Sikorsky innovations rapid prototyping group will lead the HEX programme. Led by its director, Igor Cherepinsky, the innovations team will design, build and integrate the HEX airframe and electric motors with the company's Matrix autonomy flight control system.

Depending on insights learned from the flight test programme and assessment of customer applications, the HEX programme could lead to a family of eVTOL vehicles scaled to carry passengers and payload for both military and commercial applications.

Sikorsky's Matrix autonomy system will control flight aboard the HEX aircraft. Developed and tested extensively over the past decade, the software, hardware and sensors that comprise the Matrix system have demonstrated high flight reliability in low-altitude and obstacle-rich scenarios. During the US Army's Project Convergence 2022 exercise, a Matrix-controlled Black Hawk helicopter without pilots or crew on board demonstrated optionally piloted resupply missions.