Los Angeles-based hybrid-electric aircraft developer Ampaire has taken an important next step in electrifying the aviation sector, beginning a one-month demonstration program flying a hybrid-electric aircraft between Hawaiian island destinations.
Ampaire says it is the first company to complete a demonstration flight of a hybrid-electric aircraft along an actual airline route – a 20-minute flight from Maui’s Kahului Airport across the island to Hana and back on a single charge.
The company is now flying the route regularly in a one-month demonstration program with Hawaii’s Mokulele Airlines, one of 15 airlines to have signed a Letter of Interest with the company.
Ampaire had flown several test flights before beginning this month-long demonstration program, using its Electric EEL, a six-seat Cessna 337 twin-engine aircraft modified with an electric motor in the nose and traditional combustion engine in the rear.
The Electric EEL flew a 341-mile (549-kilometre) route in California in early-October, its longest route to date and “the longest flight to date for any commercially relevant aircraft employing electric propulsion”.
“The mission was a quite normal cross-country flight that we could imagine electrified aircraft making every day just a few years from now,” said Ampaire test pilot Justin Gillen, speaking in October.

Boasting a 300-horsepower piston engine in the rear and a 160-kW-capable electric power unit in the front, plus a battery pack carried in an under-fuselage aero-optimised shell, the Electric EEL is reportedly able to reduce fuel consumption and CO2 emissions by approximately 40-50%.
For the Hawaiian demonstration flight program, the only change to ground equipment that was necessary was the installation of a 208-volt 3-phase outlet at a Mokulele hangar.
The program represents the first use of a hybrid-electric aircraft under the FAA’s Experimental-Market Survey category, allowing Ampaire to fly with their crew and essential personnel for crew training and other exploratory market activity.
“We’re following the successful path of hybrid-electric automobiles in transforming ground transportation by taking that model to the sky,” said Ampaire CEO Kevin Noertker.
“By upgrading current aircraft with hybrid-electric propulsion we can enter the market quickly and take advantage of existing infrastructure for fixed-wing aviation.”
Noertker further explained that the flight trials serve a dual purpose, demonstrating electric aviation’s potential to reduce emissions while also evaluating just how robust is Ampaire’s technology.
“We can take lessons from this series of flights and apply them to subsequent, larger aircraft designs already in the works,” said Noertker.
“The future for regional airlines is electric,” said Stan Little, CEO of Southern Airways which operates one of the largest commuter airlines in the US and owns Mokulele Airlines.
“We expect to put hybrid- and all-electric designs into service as soon as possible, and we know other regionals are watching us with great interest.”