Ampaire has accomplished the longest flight to date for any commercially relevant aircraft employing electric propulsion, in this case a hybrid-electric propulsion system.
Ampaire’s 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, took off from Camarillo Airport just north of Los Angeles. Test pilot Justin Gillen and Flight Test Engineer Russel Newman, flew up California’s Central Valley at 8,500 feet, landing at Hayward Executive Airport. Straight line distance was 292 statute miles, and the route as flown 341 statute 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 four weeks of flight testing in the Camarillo area for this second Electric EEL test aircraft, which first flew on Sept. 10. In that period, the aircraft flew over 30 hours during 23 flights, in 28 days, with 100% dispatch reliability. “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,” said Ampaire general manager Doug Shane. A former president of Scaled Composites, Shane is one of the world’s foremost experts on the development and flight testing of new aviation concepts.
“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 Hawai'i Bird as it will take part later this year in a series of demonstration flights with Hawai'i-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 Hawai'i. The Hawai'i flight trials are funded in part by Elemental Excelerator, a cleantech incubator headquartered in Honolulu.
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.
“The Electric EEL is our first step in pioneering new electric aircraft designs,” said Ampaire CEO Kevin Noertker. “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, with funding from NASA and others, is in the midst of design studies for such an aircraft based on the popular de Havilland Twin Otter aircraft. Ampaire has named the hybrid-electric 19-seater aircraft the Eco Otter SX.
