From Kahului Airport, it takes at least two hours to drive the notorious twists and turns of Hana Highway to get to Hana Airport. On a plane, it takes about 20 minutes.
If all goes well, hybrid electric planes suited to short-haul flights like Kahului to Hana could be providing service to customers by 2021.
Los Angeles-based startup Ampaire is planning to test a model of its hybrid electric plane on the Maui route in September or October in partnership with Mokulele Airlines.
“It really could be a game changer for us,” said Rob McKinney, president of Pacific operations at Mokulele Airlines. “Every time you start or stop a turbine engine, there’s a cost. With an electric motor, you would get rid of some of these costs …with less noise and with no greenhouse emissions. It’s a triple win for us and our passengers and our communities.”
With a hybrid plane, he said there would be lower operational costs, and there could be more routes and more frequent flights.
Although Mokulele was acquired in February by Southern Airways, the partnership will continue, according to McKinney. Ampaire had also been in discussions with Southern Airways about developing a hybrid electric plane to incorporate into its fleet.
“Southern Airways is completely on board, and very excited about this partnership,” said McKinney.
As part of the partnership, Mokulele has agreed to lend its hangar space at Kahului Airport on Maui, and its pilots to Ampaire.
The company was one of the 20 cohorts selected last year by Elemental Excelerator, a Honolulu startup that funds companies that fit its mission of improving lives through innovative solutions. Each cohort is awarded up to $1 million.
Elemental Excelerator was researching the global trend toward electric aviation, according to Dana Cotter, the nonprofit’s director of portfolio.
Ampaire brought its partnership with Mokulele to the table early in its application, she said, and the nonprofit found it a good fit for Hawaii, where communities rely on short-haul flights to get from island to island.
“It was a perfect, situational balance between what a local community needs,” she said, “and also, what the larger industry trends are across the globe.”
Ampaire has also looked to partner with other airlines in the Caribbean and Europe, but Hawaii’s short-haul flights are ideal for the hybridelectric planes, according to product manager Brice Nzeukou.
“Hawaii is the perfect proving ground for this technology,” said Nzeukou. “With a short flight, it shows off the technology and its benefits. Hawaii’s focus on sustainability also makes it more aligned with our own vision.”
In a growing market of electric and hybridelectric plane startups, Ampaire distinguishes itself through its approach, which is to retrofit an existing plane instead of building one from scratch.
From a regulatory standpoint, it’s simpler, according to Nzeukou, and costs are lower, although Ampaire does not have an estimated cost for developing the hybridelectric plane yet.
For its first test flights in California, Ampaire plans to retrofit a Cessna 337 Sky Master — a unique, twin-engine plane built in a push-pull configuration — with one engine mounted in the front and one in the rear.
The rear engine will be replaced with an electric motor powered by batteries, while the front will remain a conventional, piston engine.
A hybridelectric plane would potentially be able to reduce fuel costs by 50% to 70%, said Nzeukou, and maintenance costs by 25% to 50%.
A similar, Mokulele-branded aircraft will be tested on Maui, he said, in mock operational flights between Kahului and Hana airports in the fall. It is expected to carry up to six passengers.
“We’re looking to target the same payload capacity, the same weight of the aircraft, and the same range,” said Nzeukou.
The range of the hybrid plane is dependent on multiple factors, he said, but it would be capable of flying each of Mokulele Airlines’ routes with reserves, including the 100 miles from Honolulu to Kahului.
The hybrid plane’s average speed would be similar to the airlines’ existing plane, at about 150 mph.
Correction: The test plane for the Maui flights is expected to carry six passengers, not nine, as reported in an earlier version of this story.