Hybrid-electric propulsion developer Ampaire recently completed a continuous 12h flight with its Electric EEL aircraft, demonstrating the range-extending potential of its technology for regional aviation.
The Los Angeles-based start-up’s 10 December flight covered 1,195nm (2,213km), with its modified Cessna 337 Skymaster taking off and landing at Camarillo airport in California’s Ventura County. The aircraft had 2h of fuel and battery power left in reserve and was limited by remaining daylight hours rather than range.
”Hybrid-electric is actually a range extension off of the combustion engine,” Ampaire’s chief executive Kevin Noertker tells FlightGlobal on 13 December. “We get more endurance than the baseline aircraft. And it’s one thing to say it, but it’s easier to just show it when you can.”
The company says that the flight represents the world’s longest-ever endurance flight for a hybrid-electric propulsion system.
“For us, this is a meaningful and unique demonstration of a capability that has never been demonstrated before in this industry,” Noertker says. “There are a lot of people who still have this misconception that electrified aircraft are going to be hindered by performance limitations. It can’t carry much, or it can’t go very far – these are really common misconceptions that we have eliminated by going hybrid-electric.”
It wasn’t all just for show. Customers could be interested in the endurance capabilities of hybrid-electric propulsion, Noertker says, with potential applications including Earth-observation, agricultural and defence operations.
The marathon flight serves as another example of Ampaire’s show-don’t-tell development approach. Earlier this year, the company completed a multi-day, 2,955nm series of flights from Southern California to Fairbanks International airport in Alaska’s interior, which showed that Ampaire’s technology doesn’t rely on electric charging infrastructure.
“For the flight up to Alaska, that was about accessibility of this technology,” Noertker says. “It was not just that we were able to fly 3,400mi across the rugged tundra of Canada and Alaska, but that there being no infrastructure there doesn’t keep us from being able to do it.”
The journey included a weather-related diversion that forced the EEL aircraft to land back in Whitehorse, Canada, where it had taken off that morning, rather than Fairbanks. “If you’re going to be in a real operational environment, you have to be able to safely change your plans and have plenty of range,” he says.
Ampaire is pushing for certification of its AMP-H570 hybrid powertrain for the Cessna Grand Caravan, and also its so-called Eco Caravan – the hybrid variant of the 208B. In both cases, the company currently anticipates clearing certification with the Federal Aviation Administration in 2025.
The start-up also has ambitions of retrofitting aircraft larger than Grand Caravans. “It’s really about re-powering the industry,” Noertker says. ”This is scalable all the way up through the large turboprops pretty easily. We don’t see a ceiling for where this technology is applicable.”
