Strategies vary between pontoon-style and hulled
Companies developing electric aircraft capable of operating from the water are facing weight, corrosion and range challenges similar to those endured by operators of conventional seaplanes and floatplanes who have managed to carve tourism and transportation niches for their aircraft.
At least two companies have confirmed plans for electric versions in hopes of establishing their own place in the market.
Canada-based Harbour Air has been test flying an electrified De Havilland Beaver floatplane since 2019 while pursuing a supplemental type certificate for its “highly modified” aircraft through Transport Canada. In April, the company reported in a blog post that it had confronted delays due to unexpected regulatory requirements for “certifying the installation of components into an aircraft where no certification path exists.” Despite the delays, the company reported “we are committed to realizing our goal of becoming an electric commercial air operator.”
In June, meanwhile, Norwegian startup Elfly disclosed plans to develop a clean-sheet electric aircraft that would take off from and land on the water. Unlike the electrified Beaver, whose fuselage would be held above the water by struts and twin floats, Elfy’s hull would plow through the water on takeoffs and landings. Inside the hull would be a 1.4-metric-ton battery, positioned low to aid stability. Plans call for the Elfly aircraft to carry a pilot and nine passengers with luggage and have a range of 170 kilometers. So far, Elfly has tested scale models of its plane on the water without flying them.
“In Norway, it takes a long time to drive to many places because of mountains and fjords, but you can do it really efficient by using seaplanes,” explained Eric Lithun, the Norwegian entrepreneur who founded Elfly in 2018, in July at the Vertical Flight Society’s symposium in Oshkosh, Wisconsin. “Municipalities want to have a seaplane port in their local community because it’s good for the people living there, for their mobility,” he added.
Lithun also said the planned aircraft would aid Norway with its national goal of becoming carbon neutral by 2030.
The planned range would be enough to fly from the city of Bergen on Norway’s west coast, where Elfly is headquartered, to the city of Stavangar, which is about 200 kilometers away by car due to the twisting route over rugged terrain, Lithun said. He added that the aircraft, as yet unnamed, will be amphibious, meaning they will have wheels to operate from runways too.
Engineering challenges have long kept seaplanes and floatplanes limited in terms of the distance they can travel, fuel they can carry and, in turn, where they can operate efficiently. Lithun said the company is aware of the challenges such aircraft have presented through history.
“We need a rugged, lightweight hull that can also withstand corrosion,” he said. “All seaplanes today are really land-based planes where somebody removed the wheels and put them on the sea, where they were not intended to operate.”
Pat Anderson, a professor at Embry-Riddle Aeronautical University in Florida, told me that all water-capable aircraft, whether they land on their hull or on floats, tend to be heavier than other planes because the airframe must be able to withstand landing on choppy waters. Such aircraft “are built to be very durable and are not very aerodynamically efficient, especially when you put floats on them,” Anderson said. “And there’s a place for that, for incredibly rugged airplanes, but they just won’t have a whole lot of speed or range. And the reality is batteries don’t carry enough energy yet to support any commercially viable missions for such a plane.”
Such limitations mean that water-capable aircraft have mainly been flown for pleasure or to bring supplies to remote areas that lack landing strips or helipads, he said.
Lithun thinks his aircraft will do all that, and, he suggested, potentially much more in coastal regions. “LA is probably one of the world’s worst cities when it comes to commuting,” he said in Oshkosh, without elaborating.
Mostly, though, Lithun has discussed traditional markets for such aircraft. After his presentation, he expressed special interest in “island hopping,” such as in the Maldives island nation in the Indian Ocean, where seaplanes are common.
“We are planning large windows to appeal to tourists and sightseeing flights,” he said, adding that such flights fetch a higher dollar-per-hour airfare than other forms of travel.
Indeed, seaplanes are still very common in the Caribbean, said Bob van der Linden, curator of aeronautics at the National Air and Space Museum in Washington, D.C.
“They’re ideal for flying in islands, especially if there are bays and places with calm water to land,” van der Linden said. “The weight problem is what is holding electric airplanes back, and they’re limited in their speed, but that’s not necessarily critical for island hopping. They’re not going to be doing 600 miles an hour anyway from island to island.”
