Ampaire’s Eco Caravan, a nine-seat regional aircraft, made its first flight on a fully-integrated hybrid-electric propulsion system. Ampaire expects it to be the first electrified regional aircraft to enter commercial service (certification in 2024) and the first in a series of larger Ampaire hybrid-electric aircraft. (Earlier post.)

The Eco Caravan upgrades the standard Cessna Grand Caravan with Ampaire’s integrated propulsion system of a compression ignition engine and an electric engine. A battery pack in a body fairing preserves passenger and cargo capacity for the aircraft.

Earlier this year, Ampaire selected Electric Power Systems (EP Systems) under an exclusive agreement to supply the propulsion battery pack for the Eco Caravan.

The EPiC Energy storage system from EP Systems cell technology offers an energy density of more than 200Wh/kg at the battery pack level while providing more than 2,000 fast-charge cycles before a replacement is required given typical usage. The EPiC series of products consists of modular building blocks that allow customization at the aircraft level.

Ampaire already has operational experience with EP Systems technology, flying a prototype of the EPiC system on its Electric EEL flying testbed aircraft.

The Eco Caravan reduces fuel consumption and emissions by up to 70%. Emissions are near zero when using sustainable aviation fuel. Cost of operation is reduced by 25 to 40 percent depending on airline route structure. Cost per available seat mile is near that of driving.

Aviation is the hardest industry to decarbonize. Fully-electric aircraft are range limited because of the weight and energy capacity of current-generation batteries. Hybrid-electric aircraft, however, can preserve the range and utility of today’s aircraft. That is why we are focused on hybrid-electric propulsion for a series of increasingly capable regional aircraft. It’s a way for the airline industry to decarbonize more quickly and also to benefit from lower operating costs.

—Ampaire CEO Kevin Noertker

In October, Ampaire announced a relationship with Air France Industries KLM Engineering and Maintenance (AFI KLM E&M) for a range of worldwide maintenance service and support activities. Also last month, Ampaire received an order from MONTE, a financier of sustainable regional aviation technologies, for up to 50 Eco Caravans.

The first flight was 33 minutes in duration to make initial checks of the propulsion system. The Eco Caravan climbed to 3,500 feet at full power, combining power from the combustion engine and electric engine. Test pilot Elliot Seguin then throttled back to a cruise setting, reducing load on both power sources. He spent roughly 20 minutes testing various power settings while studying temperatures and other readings before making a descent and final approach to Camarillo at a low power setting.

The hybrid-electric aircraft preserves the range/payload capability of the Grand Caravan, and in fact can fly farther than the Grand Caravan with eight passengers. Maximum range is beyond 1,000 miles. The Eco Caravan’s range and load hauling capability is in marked contrast to proposed all-electric, hydrogen-electric and even other hybrid-electric designs.

The Eco Caravan can recharge its batteries in flight or at a charging stations on the ground. Because charging infrastructure will be limited for some years, the ability to operate independent of ground charging is critical for preserving the full utility of the Eco Caravan, Ampaire said

The Eco Caravan’s propulsion technology is scalable to larger regional aircraft and ultimately to single-aisle airliners. Ampaire plans to roll out more powerful propulsion systems for larger aircraft.

Ampaire is already working with the FAA to certify the Eco Caravan in 2024 under a supplemental type certificate (STC). The Ampaire approach differs from others in that it does not require a full aircraft certification program, which can be time-consuming and very expensive. The Grand Caravan is already FAA-certified. Ampaire will certify it to fly with a new propulsion system.