Green Taxi Targets Hybrid-electric Airliner Taxiing By 2027

Green Taxi Aerospace says it expects to secure the first supplemental type certificates in 2027 for hybrid-electric technology that reduces emissions from airliners taxiing to and from airport gates. At the Future Aero Festival in Amsterdam earlier this month, the U.S. start-up’s CEO and founder David Valaert said it is now working with Delta Airlines and Embraer to fit the system to E175 regional jets.

The Green Taxi system uses power from APUs to charge electric motors fitted in the aircraft’s main landing gear. The company says that by avoiding the need to taxi with power from the main engines, this approach can reduce fuel burn for short-haul flights by between 5% and 20%.

“There is nothing else that can save this [level of fuel reduction] that we can have deployed in under five years,” Valaer stated. “A jet engine is not designed to run on the ground, where its fuel flow is about 60% at idle.”

According to Green Taxi, the additional power required to taxi with an aircraft’s main engine also causes additional wear on the brakes. Valaer described this as akin to unnecessarily “driving a car with the gas pedal halfway down.”

Hardware Gets Lighter

Incremental improvements in automotive technology has made the aviation use case more viable. “Ten years ago, the system weight was significantly heavier, because the electronics alone weighed almost 200 to 300 pounds; ours weighs 20 pounds,” Valaer explained. “We did a full year of research to prove what is the most viable technology to bring to the market, and now we’re moving into the development stage.”

Green Taxi has received a $5.6 million grant from the FAA under its Fuelling Aviation’s Sustainable Transition program. The highest potential fuel savings are projected for short flights with long taxi times.

Delta Airlines has decided to prioritize installation on its E175 fleet, with each of the small twinjets typically flying 4.5 times each day. The partners have recently submitted a formal proposal to Embraer for more technical information, and in return will shortly quantify  estimated savings per year, per aircraft.

Following regulatory approval, Green Taxi’s system will be retrofitted by MRO specialist Standard Aero, with the parties submitting a joint certification plan to the FAA in November 2025. A prototype and the components for testing will be assembled mid-2026, before a conforming aircraft installation and taxi tests are completed the following year. Green Taxi will also seek approvals from EASA in Europe and ANAC in Brazil.

The company is also working with Mitsubishi Heavy Industries’ subsidiary MHIRJ about a CRJ-specific variant for the taxi system. It is also discussing options with Delta Connection, Sky West, American Airlines subsidiary Envoy Air, and Alaska Airlines’ engineering group.