Ampaire notes milestone flight for hybrid twin

On October 12 the airplane, a modified six-place Cessna 337 Skymaster twin outfitted with an electric motor in the nose and a traditional combustion engine driving a pusher propeller, took off from Camarillo Airport at 12:20 p.m. Pacific time and flew up the Central Valley at 8,500 feet, landing at Hayward Executive Airport at 2:52 p.m. The route flown by test pilot Justin Gillen and flight test engineer Russel Newman was 296 nautical miles.

In a news release, Los Angeles-based Ampaire described the flight as “the longest flight to date for any commercially relevant aircraft employing electric propulsion, in this case a hybrid-electric propulsion system.” 

The average speed was 135 mph on a flight representing “a quite normal cross-country flight that we could imagine electrified aircraft making every day just a few years from now,” said Gillen.

According to Ampaire, the Electric EEL “can generate fuel and emissions savings up to 50 percent on shorter regional routes” with the electrical propulsion unit running at high power settings. On longer regional routes such as the flight from Camarillo to Hayward, it can generate savings to 30 percent.

The flight was preceded by four weeks of flight testing at Camarillo during which the aircraft flew more than 30 hours over 23 flights in 28 days, with a 100-percent dispatch reliability, Ampaire 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,” said Ampaire General Manager Doug Shane, formerly president of Scaled Composites. “The ability to put innovative electric technologies into the air rapidly in order to assess and refine them is central to Ampaire’s strategy to introduce low-emissions aircraft for regional airlines and charter operators within just a few years.”

The aircraft flown for the tests has been named Hawai’i Bird, and “will take part later this year in a series of demonstration flights” with Mokulele Airlines on short-haul routes to “help to define the infrastructure required for wide adoption of electric aviation by airlines and airports,” Ampaire said. The demonstrations will be funded in part by Elemental Excelerator, a global climate tech accelerator based in Honolulu.

“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.”

Design studies, partly funded by NASA, are in progress for the 19-seater to be based on the de Havilland Twin Otter and named the Eco Otter SX.