United Airlines has committed to an unspecified investment in JetZero’s plan to develop a blended-wing-body aircraft. On April 24, the carrier said the agreement reached with the U.S. start-up “includes a path” to place orders for 100 of the 250-seat Z4 airliners, with options for another 100 units.

The airline did not elaborate on other aspects of the investment, but it noted that the conditional purchase agreement is contingent on JetZero achieving several program milestones, including a first flight with a full-scale demonstrator aircraft in 2027. The agreement follows a partnership commitment from Delta Air Lines announced in early March.

According to JetZero, the drag-reducing architecture for the Z4, which generates lift across the entire wingspan, is expected to result in a 50% reduction in fuel burn per passenger mile compared to existing airliners of a similar size. Pratt & Whitney and Collins Aerospace will provide the main elements for the propulsion system, which will be based on a PW2040 turbofan.

The projected range is up to 5,000 nm, and JetZero stated that the Z4 will be able to operate from existing airport infrastructure. According to the company, a flight from New York to Palma de Mallorca in Spain would use up to 45% less fuel compared to the twin-aisle widebodies currently deployed on the route.

JetZero aims to provide airlines with more flexible seating options and increased space for their passengers. The main board door will be wider than those in current airliners, which the company said will lead to multiple aisles and passenger cabin bays.

“If successful, JetZero has the potential to evolve our core mainline business by developing aircraft with a bigger, more comfortable cabin experience for our customers while increasing fuel efficiency across our network,” said Andrew Chang, head of United Airlines Ventures.