Milestone for Hybrid-Electric Propulsion: RTX Demonstrator Hits Full Power in Ground Test

RTX’s hybrid-electric aviation roadmap has reached a major benchmark: its experimental propulsion system – designed for regional aircraft – has now completed full-power ground testing. The goal? Up to 30% greater fuel efficiency and a major step toward decarbonising short-haul flight.

The push toward sustainable aviation is accelerating. On June 16, RTX announced a new milestone in its Hybrid-Electric Flight Demonstrator program: the integrated hybrid propulsion system and high-capacity batteries have successfully reached full power during ground testing in Longueuil, Québec. The demonstrator, based on a modified De Havilland Canada Dash 8-100, aims to reduce fuel consumption by up to 30% compared to today’s regional turboprops.

Developed by Pratt & Whitney Canada and Collins Aerospace – both RTX businesses – the system combines a high-efficiency thermal engine with a 1 MW electric motor. The propulsion unit is powered by 200 kWh batteries from Swiss-based H55, which were successfully charged and discharged using a custom-developed Mobile Charging Unit in collaboration with the National Research Council of Canada and the Innovative Vehicle Institute.

“This end-to-end test marks a critical achievement,” said Jean Thomassin, Executive Director, New Products and Services Introduction at Pratt & Whitney Canada. "It paves the way for flight testing and supports our broader hybrid-electric development strategy.”

That flight testing will be led by AeroTEC, which joins De Havilland Aircraft of Canada as a key partner. AeroTEC will modify the Dash 8-100 and manage flight test operations. “Our role is to bring this revolutionary technology into the sky,” said AeroTEC President Justin Morigeau. “It’s about demonstrating what sustainable regional aviation could look like in the near future.”

Other program partners include GKN Aerospace, responsible for high-voltage wiring systems, and Ricardo, which is contributing to propulsion integration. Together, these players form a highly specialised development network focused on bringing the hybrid-electric system to real-world performance levels.

The demonstrator is a flagship in RTX’s broader sustainability roadmap. Alongside other initiatives like the Clean Aviation SWITCH project, which aims to develop a hybrid-electric GTF engine, the group is leveraging its combined propulsion and electrical systems expertise to enable next-generation efficiency gains.

Hybrid-electric: More than just efficiency

While the headline goal is fuel burn reduction, hybrid-electric propulsion also offers other benefits: reduced noise, greater operational flexibility, and the long-term potential to integrate with hydrogen or SAF-based (sustainable aviation fuel) systems. According to IATA, regional turboprops account for roughly 10% of global aviation emissions – making them a logical starting point for hybridisation.

RTX’s work on this front also positions it as a technology leader in a sector where innovation timelines are long and certification pathways complex. If successful, the program could accelerate the availability of low-emission propulsion systems for new aircraft platforms entering service in the 2030s.