What if aircraft engines were electric?
The engines Pratt & Whitney produces already are 70 percent more efficient than they were 30 years ago, said Graham Webb, the business’ chief sustainability officer. In 2022 alone, more than 1,000 orders for the company’s GTF engines will reduce fuel consumption and carbon emissions by 16 to 20 percent compared to the previous generation.
But new hybrid electric technology, he said, would reduce emissions even faster.
“I look at it as enabling the next 100 years of Pratt & Whitney,” Webb said.
In Quebec, Canada, RTX is working with the federal and provincial governments on a regional aircraft flight demonstrator that would use a one-megawatt electric motor from Collins Aerospace to help power the takeoff and ascent – the most energy-intensive stages of flight – of a De Havilland Canada Dash 8-100 turboprop plane. In December 2022, a hot engine test showed the concept is on track for flight testing in 2024.
The system is expected to reduce fuel burn and carbon emissions on small aircraft by 30 percent, and could also bring a significant reduction when scaled up to larger single-aisle passenger planes.
“I think it just shows the power of what we can do,” said LeAnn Ridgeway, chief sustainability officer at Collins Aerospace, an RTX business. “Once you start designing together, you’re getting all kinds of efficiencies, and that’s pretty exciting.”
There’s a similar level of collaboration in STEP-Tech, which stands for scalable turboelectric powertrain technology. The project, based at the Raytheon Technologies Research Center in Connecticut, consists of a “Lego set” of modular components that will allow the team to test various configurations quickly.
It has three sections, set up in the lab similar to how an aircraft would produce power. On a jet burner stand, there’s a turbogenerator that connects to the electrical section, which consists of lithium-based batteries, supercapacitors and a high-voltage power distribution system. That section powers a series of fans that create propulsion in an acoustic wind tunnel.
The project’s creators can easily swap out any piece of the demonstrator to see how a slightly larger motor would perform, for instance, or use 3D printing to create plastic fans of different sizes and shapes.
“We’re leveraging modularity and scalability,” Baig said, “to be able to test and learn on different architectures very fast.”
The demonstrator is focused on concepts in the 100- to 500-kilowatt class, with potential to grow up to one megawatt, and it has applications in commercial, military, unmanned and passenger aircraft. With its first test complete, Baig and his team will use the data gathered to refine their concept and complete a full system test.
Seeing STEP-Tech successfully test its first prototype has been one of Webb’s favorite moments of the year.
“It’s always great to talk concepts and work with models and those types of things,” Webb said, “but when you actually have hardware to bring together, fire it up and it works – that, for an engineer, is what it’s all about.”