The battle to build America’s next generation of AI-powered fighter drones is heating up, with defense giants racing to dominate what analysts say could become a multibillion-dollar military market.

At this week’s Farnborough Airshow in the UK, Boeing rolled out its flight-ready Ghost Bat combat drone while rivals General Atomics and Anduril Industries unveiled full-scale models of their own uncrewed aircraft, all designed to fly alongside manned fighter jets as autonomous wingmen.

The competition also includes Lockheed Martin, Northrop Grumman and Europe’s Airbus, as militaries prepare for a future in which human pilots could be backed by fleets of AI-controlled aircraft.

The U.S. Air Force expects the drones to cost a fraction of an F-35 fighter jet, which carries a price tag of more than $80 million. Industry analyst Richard Aboulafia said the market could eventually produce hundreds of aircraft each year, although widespread deployment is not expected until the mid-2030s.

Boeing says it has a head start.

The company describes its Ghost Bat as the most advanced aircraft in the new generation of autonomous combat drones. Earlier this month, it became the first to take part in a multinational military exercise led by the United States after successfully completing a live-fire test against an aerial target in December.

“We’ve got the most mature collaborative combat aircraft,” Boeing Vice President Bernd Peters told Reuters. “It’s real hardware you see in front of you.”

Boeing has been developing the Ghost Bat since 2017 and is building seven aircraft for the Australian Defense Force under a three-year contract worth 754 million Australian dollars (about $528 million). The company says the aircraft has completed more than 100 test flights.

Its rivals insist they’re closing the gap fast.

“In two years, we have surpassed what a lot of other companies have been working on for many years,” said Jason Levin, a senior vice president at defense startup Anduril. “Rather than just making small incremental steps, we like to make large steps.”

The Air Force has already awarded production contracts to Anduril and General Atomics under its Collaborative Combat Aircraft program, which aims to field the military’s first fleet of semi-autonomous fighter drones.

Last week, the Air Force completed a live-fire test with an Anduril aircraft over California’s Mojave Desert. The company has also begun building its FURY combat drone at a new Ohio factory and says it could eventually produce as many as 150 aircraft a year.

General Atomics, best known for the Predator drone, said it has already built multiple aircraft for the Air Force program. Company spokesman Phil Ewing said the biggest leap isn’t the aircraft themselves—it’s the autonomous software that allows them to fly and fight with minimal human input. He said the company has logged “thousands and thousands” of hours of autonomous flight testing.

The Air Force plans to choose a lead contractor for the first phase of the program by the summer of 2027 and hopes to buy more than 150 combat-ready drones before the end of the decade.

Lockheed Martin is also developing its own autonomous combat aircraft and says its first prototype is expected to fly next year.

The race is expanding beyond the United States. Boeing is partnering with German companies to offer the Ghost Bat to Germany’s air force by 2029, while Airbus unveiled its U760 Ravenstorm drone and expects it to enter service in the early 2030s.