Air Force says it's testing a next-generation fighter jet

Roper revealed that the prototype has begun flight testing Tuesday during the Air Force Association's virtual Air, Space & Cyber Conference.

This marks the nearly the first flight of an experimental fighter in 20 years.

"We've already built and flown a full-scale flight demonstrator in the real world, and we broke records in doing it," Will Roper, the Air Force's acquisition chief, told Defense News. "We are ready to go and build the next-generation aircraft in a way that has never happened before."

The development of the prototype happened in secret, and other details will likely remain under wraps due to the classification of the Air Force's Next Generation Air Dominance Program, which connects air warfare systems that could include fighters, drones and other networked systems.

Roper did not say how many prototype aircraft have been flown or which defense contractors manufactured them, nor did he disclose when or where the first flight occurred.

It's also unclear whether the aircraft is a traditional piloted aircraft or a drone.

The last flight of an experimental fighter took place during the battle for the Joint Strike Fighter contract, and the rollout and successful first flight of a demonstrator was not expected for years.

"We're going after the most complicated systems that have ever been built, and checked all the boxes with this digital technology," Roper said. "In fact, [we've] not just checked the boxes, [we've] demonstrated something that's truly magical."