Assembly Begins On First Bye eFlyer 2 Electric Trainer

The switch to Safran’s air-cooled EngineUS 100 electric motor has reshaped the spinner and cowl of Bye’s eFlyer 2.
Credit: Bye Aerospace

Assembly has begun on the first production prototype of Bye Aerospace’s two-seat, all-electric eFlyer 2.

It is the first of three conforming aircraft that will be used for flight testing to obtain FAA Part 23 certification for the flight training market.

Bye has contracted with Composites Universal Group (CUG) for tooling and construction of the carbon-fiber fuselage for the eFlyer 2. Founded to provide composite components to the experimental aircraft industry, CUG has begun assembly of the first fuselage, which will be the first major component to be delivered to Bye for final assembly.

Bye is projecting 80% lower operating costs for the all-electric eFlyer 2 versus available piston-powered training aircraft, with no CO2 emissions and decreased noise. 

The first ell-electric aircraft to receive type certification, the Pipistrel Velis Electro, was approved in Europe in May 2020 and is also aimed at the training market. The Slovenian manufacturer delivered 111 Velis Electros in 2020, outpacing its production of gasoline-powered light aircraft. In France, Pipistrel has partnered with Green Aerolease to make an initial 50 of the electric trainers available for rent to flight schools and flying clubs.

Denver-based Bye, meanwhile, previously flew an eFlyer 2 technology demonstrator, which was an existing kit plane converted to battery-electric propulsion. The demonstrator was powered by a Rolls-Royce (formerly Siemens) motor, but this has been replaced in the production aircraft with a Safran motor.

“Since mid-November the transition to the Safran motor continues to go well,” CEO George Bye said. “[Safran’s] technical team has done a great job working with our engineers through the various eFlyer 2 configuration updates needed for its new air-cooled motor.”

The production eFlyer will be powered by a Safran EngineUS 100 motor with a target peak rating of 115 kW (150 hp).  “We are pleased with the weight, performance, configuration, safety and redundancy built into the Safran ENGINeUS electric smart motor design,” Bye said. 

Among modifications to the eFlyer 2 design resulting from the new motor are “important but subtle changes around the spinner and nose area, and then the side of the cowl,” he said.  Compared with the Rolls-powered demonstrator, the production eFlyer 2 has a larger spinner.

Editor's note: This article has been edited to correct the target peak rating of the eFlyer's engine.

Graham Warwick

Graham leads Aviation Week's coverage of technology, focusing on engineering and technology across the aerospace industry, with a special focus on identifying technologies of strategic importance to aviation, aerospace and defense.