Nimbus Launches Scaled Hybrid-Electric Jet

A proof-of-concept flight has demonstrated that aviation startup Nimbus Aerospace’s over-the-wing distributed ducted fan propulsion system is a viable way to power an aircraft. 

In December 2024, the Seattle-based firm successfully flew a 1/10th-scale model of its N1000 XSS, an electric-powered business jet. The launch consisted of taking off, flying three circular patterns with both gear-down and gear-up configurations, and safely landing, for a total time of one minute and 23 seconds in the air.  

“This first flight has been the most nerve-wracking moment in our journey,” said Nimbus Aerospace co-founder and CTO Akim Niyonzima. “After having such a tight schedule for designing, fabricating, and testing, watching our model successfully lift off and validate all the engineering work that went in it was an incredible feeling.” 

Distributed propulsion system 

The N1000 XSS model has a wingspan of 73 inches, a length of 68 inches, and a height of 16 inches. This scaled prototype, supported by a proprietary clean sheet airframe, was assembled in less than one month using both customized and off-the-shelf parts.  

“What makes our work particularly impressive from a mechanical engineering standpoint is the seamless integration of bespoke and off-the-shelf components, within such a compressed timeline,” Niyonzima said. “Achieving structural integrity, precise tolerances, and aerodynamic efficiency while balancing rapid prototyping constraints required an agile design approach. We had to optimize manufacturability without compromising performance, thereby leveraging advanced fabrication techniques, rapid iteration cycles, and a deep understanding of material properties.” 

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This test flight also proved that its over-the-wing distributed ducted fan propulsion system (DEP) is viable for aircraft.  

“DEP has been the main differentiator compared to the earlier airframe designs we made,” Niyonzima added. “We completed computational fluid dynamics [CFD] analysis for all airframe concepts in various conditions to optimize the best performance for our design goals.” 

Although there are several airframe designs that use a DEP system, “to our knowledge, none have been tested for performance or gone through the rigorous testing we have done on the N1000 XSS,” Niyonzima said. 

With the distributed propulsion system’s successful flight, done in combination with a conventional airframe, the engineering team was able to evaluate the airframe configuration’s performance, its flight characteristics, and any limitations.  

Future plans 

The Nimbus team built and tested two previous models. That data, plus the results from all the simulations and flight tests in December, was invaluable in designing the current airframe configuration. A thorough analysis of the flight tests and advanced CFD data enabled the team to optimize the design for higher performance. “We are currently building a bigger and higher performance sub-scale model [1/4] that will be flight-tested before the end of 2025,” Niyonzima said. 

All the analytical work also proved that the team’s predictions for the models were highly accurate. “Given the depth of our engineering and pilot experience within our team—from designing to flight testing to subscale prototyping—we had strong confidence in our design and performance expectations,” Niyonzima said. “While there weren’t any major surprises, it was still gratifying to see the data align so closely with our simulations, reinforcing the validity of our predicted performance.” 

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Nimbus Aerospace hopes to build a jet craft that can fly up to 1,100 miles with seating for six to eight passengers. “Private jets are between five and 14 times more polluting per passenger than commercial airplanes, making them the most environmentally harmful form of transportation,” said Adrian Groos, Nimbus Aerospace CEO and co-founder. “To meet the industry’s net-zero carbon emissions goals by 2050, thousands of new and sustainable private aircraft will be needed over the coming decades.” 

If things go as planned, the Nimbus team hopes to receive Federal Aviation Administration certification and begin production of its electric jets by 2032. 

Mark Crawford is a technology writer in Corrales, N.M.