According to Electrive, one of the companies that does this is Ampaire, a California-based manufacturer that recently completed the maiden flight for its nine-seater hybrid-electric plane.
The aircraft was able to fly for around 200 minutes and it reached an altitude of over 1.000 meters, using both the internal combustion engine and the electric motor.
While settling for a cruise speed, the pilot tested multiple combinations for both propulsion systems for a few hours before completing the flight.
Test pilot Elliot Seguin said that "the craft was smooth and quiet. All temperature and power output readings were normal."
The Californian aerospace company had another test flight back in 2019 involving a hybrid six-seater called the Ampaire 337.
This year in October, the company received an order of as many as 50 Eco Caravans from Monte, a financier of sustainable regional aviation technology.
That the same month, Ampaire officials announced they will collaborate with Air France Industry KLM Engineering for global maintenance and support.
Kevin Noertker, Ampaire’s CEO, said that "fully-electric aircraft are range limited because of the weight and energy capacity of current-generation batteries."
"Hybrid-electric aircraft, however, can preserve the range and utility of today’s aircraft. That is why we are focused on hybrid-electric propulsion for a series of increasingly capable regional aircraft", he added.
Archer Aviation is another manufacturer of eco-friendly planes and it plans to build 250 battery-electric air taxis by 2025, which should help regional flight operators decarbonize their operations.
Electric plane manufacturer Eviation takes a little bit of a different approach with its more luxurious battery-electric plane that was able to fly for around eight minutes at 1.000 meters.