Ampaire Raises $19 Million for Hybrid-electric Airplanes

Hybrid-electric propulsion developer Ampaire has raised $19 million in a Series B round led by DiamondStream Partners, the company announced on August 18. Corporate venture arms of two airline groups joined the round: Alaska Star Ventures, which invests on behalf of Alaska Airlines, and IAGi Ventures, part of London-based International Airlines Group.

Long Beach, California-based Ampaire has now raised $68 million since its founding in 2016, roughly $25 million of which came from grants and contracts awarded by the U.S. Air Force, the Department of Energy’s ARPA-e program, and NASA.

“This financing is about turning proven hybrid-electric performance into commercialized products and scaled operations,” said Ampaire co-founder and CEO Kevin Noertker. “We have consistently demonstrated the technology in flight; this capital accelerates our deployment with customers, and expands our supply chain, manufacturing, and operating capabilities required to reach commercial scale.”

Ampaire said the fresh funding will go toward hiring, supplier development, early manufacturing capability, aftermarket support, and additional Eco Caravan aircraft, the hybrid-electric conversion of the Cessna 208B Grand Caravan that serves as Ampaire’s launch product. It will also fund expanding operations under the FAA’s eVTOL Integration Pilot Program (eIPP), for which Ampaire recently began demonstration flights in Utah, along with certification work on two fronts: a Part 33 program for the 570-kilowatt AMP-H570 powertrain and a Part 23 supplemental type certificate (STC) for the Eco Caravan.

Noertker told AIN that he expects the Series B money will be enough to support the company through type certification for the AMP-H570 and Eco Caravan in 2027. “Our next funding round will support further production scale-up,” he said.

Ampaire obtained an FAA G-1 issue paper for the AMP-H570 in May 2025, which the company says was the first such certification basis granted to a hybrid powertrain. Its flight-test fleet has logged more than 38,000 hybrid-electric miles, according to the company, most recently on the eIPP demo routes in Utah. Ampaire says the Eco Caravan burns 54% to 57% less fuel than a standard turboprop Caravan.

The IAGi relationship predates the investment; Ampaire joined the group’s innovation program last year, working with the group to adapt its hybrid-electric technology for auxiliary power unit (APU) applications on existing and new commercial aircraft, according to IAGi Ventures managing partner Raza Ali. 

“What excites us most is its practical approach to reducing aviation emissions by applying hybrid-electric technology to aircraft already in service today,” Ali said in a statement. “The team has made impressive progress, and we look forward to exploring how hybrid-electric APU solutions could reduce aircraft fuel consumption on the ground.”

The fundraising comes as some competitors have pulled back. Surf Air Mobility, which in 2022 scuttled its plans to acquire Ampaire, stepped back from its own hybrid-electric Caravan conversion effort in March, eliminating an estimated $100 million in planned spending on the program and pivoting to a partnership with Beta Technologies on all-electric aircraft instead. Meanwhile, ZeroAvia, which is pursuing hydrogen-electric retrofits for the same class of regional airplanes, recently halved its workforce and pushed its certification target past 2027.