What Raytheon’s STEP-Tech Demonstrator Will Bring to Advanced Air Mobility

In July 2022, Raytheon Technologies (Pratt & Whitney and Collins Aerospace) announced the launch of a new hybrid-electric technology demonstrator program aimed at future advanced air mobility systems. The Scalable Turboelectric Powertrain Technology (STEP-Tech) demonstrator expands the development of hybrid-electric technology in an effort to achieve sustainable aviation goals.

The STEP-Tech demonstrator is based on a modular and scalable platform. It is intended for rapid prototyping of distributed propulsion concepts applicable to various future applications, including advanced air mobility vehicles, high-speed VTOL, and blended wing body aircraft.

The program focuses on developing high voltage distributed turboelectric hybrid-electric propulsion concepts in the 100-500KW class, with the potential to scale much greater. The company began ground testing in late 2022, followed by the completion of its first engine run and electrical system integration test in June of this year. The Chief Technology Officer of Raytheon Technologies (RTX), Mark Russel, commented,

“Hybrid-electric propulsion is a key part of RTX’s roadmap for enabling more sustainable aviation, with the potential to enhance efficiency across many future aircraft applications, from advanced air mobility to regional aircraft and single-aisles. Harnessing deep expertise from Pratt & Whitney, Collins Aerospace, and Raytheon Technologies Research Center in the fields of both aircraft propulsion and electrical systems, RTX is leading the development of hybrid-electric technology through multiple demonstration programs, including STEP-Tech.”

Hybrid-Electric technology

The demonstrator program aims to advance hybrid-electric technology to a range of applications, including unmanned aerial vehicles (UAVs) and small to medium-sized commercial airplanes. Industry-wide developments in hybrid-electric technology have shown challenges with payload and range.

A De Havilland Canada aircraft with hybrid-electric engines in flight.

Photo: Raytheon Technologies

The STEP-Tech demonstrator will include full end-to-end system capabilities, including high-efficiency propulsion systems, energy storage, power electronics, and modular-driven electrical propulsors. The program is also aimed at advancing hybrid-electric propulsion, supported by the governments of Canada and Quebec. According to Henry Brooks, the President of the Power & Controls division at Collins Aerospace,

“With Pratt & Whitney’s track record in aircraft propulsion and Collins’ legacy of innovation in electric power systems, we are exceptionally well-positioned to lead the advancement of hybrid-electric technology for the next generation of sustainable aircraft.”

Successful testing of the turbogenerator

The company conducted one of the first runs of the STEP-Tech’s turbogenerator at the Reytheon Technologies Research Center in East Hartford, Connecticut. The turbogenerator, loaded at partial power for the test, included battery packs and a supercapacitor energy storage system.

The insides of an aircraft engine.

Photo: Collins Aerospace

The test enabled the validation of various circuits within the system and the overall integrity of the high-voltage distribution system. In the coming months, the company plans to perform a full-power test of the turbogenerator to validate electric propulsors through the high-voltage electrical system.

The STEP-Tech demonstrator is one of many programs the company and its collaborators participate in. These demonstrators are part of a company-wide strategy to advance research and development of sustainable aviation technologies. The company aims to leverage public and private partnerships to support the aviation industry’s goal of achieving net zero carbon emissions by 2050.

What are your thoughts on the STEP-Tech demonstrator and its applicability in various air mobility designs? Tell us in the comments section.