美国6代机的技术验证机,美国空军已经证实在2020年就首飞了
On September 15, 2020, then-U.S. Air Force acquisition executive Dr. Will Roper announced that the Air Force had flown a full-scale flight demonstrator as part of the NGAD program.
https://news.usni.org/2022/06/24/report-to-congress-on-air-force-next-generation-air-dominance-program
当然,从原型机到量产还有一段距离