Ampaire hybrid-electric Eel aircraft makes 341 mile test flight


The electric Eel test aircraft has flown its longest journey yet and set a new record for the longest electrically-powered flight for a commercial aircraft, according to its US-based developers, Ampaire.

Ampaire’s Electric Eel is a six-seat Cessna 337 twin-engine aircraft modified with a hybrid-electric propulsion system – an electric motor in the nose and traditional combustion engine in the rear.

Ampaire has so far developed two test aircraft. The 341 mile flight, which was made with the second test aircraft the “Hawai‘i Bird”, took place on October 8 between Camarillo Airport north of Los Angeles and Hayward Executive Airport in California, USA.

Test pilot Justin Gillen and flight test engineer Russel Newman flew up California’s Central Valley at 8,500ft. Straight line distance of the flight was 292 miles, and the route as flown 341 miles.

Speed during the cruise portion of the 2 hour, 32-minute flight averaged around 135 mph. “The mission was a quite normal cross-country flight that we could imagine electrified aircraft making every day just a few years from now,” Gillen said.

This milestone in electric aviation took place after the Hawai‘i Bird had undergone four weeks of flight testing in the Camarillo area. During that period, the aircraft flew over 30 hours during 23 flights, in 28 days, with 100% dispatch reliability.

Ampaire’s general manager Doug Shane said, “Our success in taking this aircraft in a short period from the test environment to the normal, everyday operating environment is a testament to our development and test organization, and to the systems maturity we have achieved with our second aircraft,”

“The ability to put innovative electric technologies into the air rapidly in order to assess and refine them,” he added, “is central to Ampaire’s strategy to introduce low-emissions aircraft for regional airlines and charter operators within just a few years.”

The EEL flown to Hayward is dubbed the Hawaiʻi Bird because it will take part later this year in a series of demonstration flights with Hawaiʻi-based Mokulele Airlines on its short-haul routes. The flight trials with Mokulele will not only demonstrate the capabilities of the Eel but will help to define the infrastructure required for wide adoption of electric aviation by airlines and airports.

These flight demonstrations will mark the first time an electrically powered aircraft has flown under an FAA “Market Survey” experimental aircraft certificate in order to gain real-word flight experience.

In Hayward, the aircraft will be partially disassembled for shipment to Hawaiʻi. The Hawaiʻi flight trials are funded in part by Elemental Excelerator, a cleantech incubator headquartered in Honolulu.

According to Ampaire, the Electric Eel can generate fuel and emissions savings up to 50% on shorter regional routes where the aircraft’s electrical propulsion unit can be run at high power settings, and generate savings of about 30%  on longer regional routes such as the Camarillo to Hayward flight.

Ampaire’s CEO Kevin Noertker said, “The Electric EEL is our first step in pioneering new electric aircraft designs. Our next step will likely be a 19-seat hybrid electric retrofit program that will lower emissions and operating costs, benefiting regional carriers, their passengers and their communities.”

Ampaire and aircraft services company Ikhana have been designing a 19-seat hybrid-electric aircraft based on the popular de Havilland Twin Otter aircraft, to be called the Eco Otter SX, since October 2019 as part of a NASA-funded project.

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Ben has worked as a journalist and editor, covering technology, engineering and industry for the last 20 years. Initially writing about subjects from nuclear submarines to autonomous cars to future design and manufacturing technologies, he was editor of a leading UK-based engineering magazine before becoming editor of Aerospace Testing in 2017.

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