Whisper Aero completes piloted flight tests of electric ducted-fan propulsion

Whisper Aero has started piloted testing of an electric propulsion system fitted to a modified Aériane Swift 3 glider in Tennessee. Test pilot Zac Majors flew the aircraft three times, totaling 130 minutes, using two of the company's eQ250 electric ducted-fan units.

Each eQ250 is designed to produce up to 80 pounds of thrust. Power comes from five battery modules supplied by Electric Power Systems. The company has projected a cruise speed between 42 and 55 knots, a climb rate of 1,250 feet per minute, and a powered range of around 109 miles.

The project builds on a partnership with Tennessee Tech announced in April 2025 and received a $500,000 award from the Tennessee Department of Economic and Community Development. University faculty and students supported ground testing of the engines, batteries and controllers before the powered flights took place.

Before installing the propulsion system, Whisper had flown the unpowered glider in Tennessee under an experimental airworthiness certificate, gradually increasing aircraft weight to assess handling at levels expected once the powertrain was added.

During one low-altitude, full-power pass at 100 feet above ground level, the company recorded a noise level of about 52 dB(A) against a background of 34 dB(A). Whisper said the initial powered flights met their objectives for evaluating the propulsion installation, batteries and control systems. The company plans further test flights in Tennessee ahead of evaluations with government customers later this year.