United Airlines (UA, Chicago O'Hare) and Mesa Airlines (YV, Phoenix Sky Harbor) have signed an investment agreement with Swedish electric aircraft manufacturer Heart Aerospace (Gothenburg City), which could potentially lead to each of the carriers ordering 100 all-electric 19-seat ES-19s.

The agreement covers an undisclosed investment into the start-up by United Airlines Ventures, the investment arm of the carrier, Mesa Airlines, and investment fund Breakthrough Energy Ventures. The capital injection is earmarked to help Heart Aerospace bring the ES-19 to market, currently scheduled for 2026.

"Having Mesa as a partner will be an invaluable asset for us. They know the business of operating 19-seaters like few others, and they bring unique operational insights that we feed directly into the design of our plane. Mesa has decades of experience in operating 19-seaters, so we do not need to reinvent the wheel. We couldn’t be more excited about reconnecting America together with Mesa," Heart Aerospace CEO Anders Forslund said.

The formal order for the ES-19s is subject to the type meeting unspecified safety, business, and operating requirements with each of the carriers.

In its press statement, Mesa Airlines underlined that it was once the world's largest operator of 19-seat aircraft - including Beech 1900Cs, Beech 1900Ds, and Metroliners - only to abandon them once they became unprofitable. However, it stressed that with electric propulsion, lower operating costs, and reduced noise and emissions footprint, the 19-seat market could see revival benefitting in particular third-tier regional airports, which currently see no scheduled traffic.

United Airlines indicated that the ES-19 could take over many of its short-haul feeder flights in the future, given Heart is looking to achieve a 250 nautical mile range for the type.

The investment follows earlier expressions of interest by United in new types of aircraft. In February 2021, the carrier announced an undisclosed investment and a potential order for 200 electric vertical-take-off-and-landing (eVTOL) units manufactured by Archer Aviation. If firmed, the aircraft will be operated by Mesa Airlines. In early June, it signed a tentative order for fifteen Boom Technology Overture supersonic aircraft with options for a further 35 units.