Bye Aerospace's two-seat all-electric eFlyer 2 prototype began an important next flight test phase this week with the new 90 kW Siemens SP70D production motor. Following successful flight tests earlier this spring, Bye Aerospace completed the pre-production lower-power prototype motor test program and installed the fully capable, higher-power production motor.

"During the prototype eFlyer 2 flight tests that began on July 17, the new Siemens production motor met or exceeded expectations in all performance indicator areas," said George E. Bye, CEO of Bye Aerospace. "These important tests are validating the eFlyer's incredible operating economy, efficiency, and performance while producing no CO2."

The eFlyer family of aircraft, beginning with the 2-seat eFlyer 2 aims to be the first FAA-certified, practical, all-electric airplanes to serve the flight training and general aviation markets. Siemens is providing the electric propulsion system for the eFlyer 2 airplane—the 57 lb. electric motor with a 90kW peak rating (120 HP), and a continuous power setting of 70kW (94 HP).

"Every time the Bye Aerospace team hits another milestone, we are just amazed at the rate of progress and professionalism that they display," said Olaf Otto, Head of Siemens eAircraft business unit. "We are excited to see the aircraft in operation for the first time with the SP70D and look forward to continuing the joint path to certification. From my point of view, the eFlyer 2 is going to create a whole new category of training aircraft, really demonstrating the capabilities of electric propulsion systems."

In addition to the new Siemens production motor, other modifications to the eFlyer 2 prototype included an additional battery pack, a new three-blade developmental propeller from Hartzell among the propellers being evaluated, plus an updated cowling, a new spinner, and a charger plug-in port. The return to flight begins a period of extensive flight test that will provide important flight performance data for the new Siemens motor that will also help determine other suppliers for the conforming production aircraft.

The eFlyer brings the full promise of electric propulsion to the market with safe, practical and reliable electric aircraft. The all-electric operation requires no aviation fuel and results in zero CO2 emissions and significantly lower noise pollution compared to conventional aircraft. The high quality, sleek eFlyer flight training design also features ruggedized structure and landing gear, enhanced speed and altitude performance with extremely low operating costs.