The airplane that could herald a new generation of supersonic passenger flight looks an awful lot like a fighter jet. It’s long and sleek, with a narrow wingspan, two tandem seats, and three engines blasting full afterburners to propel it to twice the speed of sound.

Look the part, be the part. “This thing will handle very much like a fighter jet,” Boom Supersonic test pilot Bill “Doc” Shoemaker says with a grin. “We have to actually limit its capabilities a bit so passengers stay comfortable.” The F/A-18s this former US Navy pilot used to fly would lose a top speed contest to Boom’s new airliner by a few hundred miles per hour.

Shoemaker is actually talking about two aircraft: a 1/3-scale demonstrator the company is building now to prove out its supersonic technology, and the full-scale airliner that, come 2025, will carry 55 passengers to Mach 2.2 at 60,000 feet altitude. To avoid sonic boom-related speed restrictions, Boom will mimic the Concorde in sticking to transoceanic routes.

For that to happen, the company has to raise about $6 billion in funding, clear all the safety and reliability hurdles required of new commercial aircraft, and be economical enough for airlines to even want the thing. Despite the appeal of going supersonic, no airline will forget the famed Concorde’s famously monstrous financial record.

“To make this whole effort successful, you need to have technology that works, customer demand, the cooperation of great suppliers in the industry, and you need to have an approach that will ensure certification and regulatory approvals,” Boom CEO Blake Scholl says from his new headquarters outside Denver. “We’re now spiraling up through all those challenges, and one of the strategies for that is to build the XB-1, which we can do with the money we already have.”

The XB-1 is that demonstrator plane, 60 feet long and dubbed the “Baby Boom.” Developed with some of the $85 million the company has raised so far, it will go just as fast as the proposed airliner, and allow engineers to assess the aerodynamic performance of their design and the structural qualities of the carbon fiber airframe, as well as the general engine setup.

The scaled-down flier will use a trio of General Electric turbojets; the airliner will use new engines that are more efficient and powerful, and thus don’t require afterburners, but don’t quite exist yet. Boom is soliciting proposals from the major engine manufacturers. In the meantime, Boom’s engineers are using wind tunnels and test facilities to develop their propulsion strategies—what works for the demonstrator will, for the most part, also work for the bigger airliner.