The U.S. Air Force officials expect the first flight of super-secret B-21 Raider long-range strike bomber to take place in December 2021.

In an op-ed for The Air Force Magazine, Air Force Vice Chief of Staff Gen. Stephen Wilson said the new B-21 Raider stealth bomber is making good progress and should fly in December 2021.

Speaking at an AFA Mitchell Institute event in Washington, D.C., on deterrence and the need to modernize the nuclear command, control, and communications network, Wilson said he was at Northrop Grumman’s facilities in Melbourne, Fla. in the last few weeks, “looking at the B-21,” and said the company is “moving out on that pretty fast.” Wilson said he has an application on his phone “counting down the days … and don’t hold me to it, but it’s something like 863 days to first flight.”

That would put the first flight of the B-21 in December 2021. The Air Force has said from the beginning that the first B-21 would be a “useable asset” but has also said it doesn’t expect an initial operating capability with the B-21 before the “mid 2020s.”

The B-21 Raider bomber is a long-range, highly survivable aircraft capable of penetrating and operating in future anti-access, area-denial environments. The new bomber will play in allowing the Air Force to operate in tomorrow’s high-end threat environment, and in providing the Air Force the flexibility and capability to launch from the continental United States and deliver airstrikes on any location in the world.

Wilson also noted that the Air Force is “focused on the development of the new bomber as well as modernizing the B-52,” with new engines and radar, “and we’re exploring the force structure between the B-1 the B-2 and the B-52.”

Although the first B-21 are expected in the mid-2020s, the Air Force doesn’t plan to retire the existing bombers until there are sufficient B-21s to replace them. The Air Force hasn’t determined which location will receive the aircraft first.

“The general consensus is, we don’t have enough long-range strike capacity, and that came out in ‘The Air Force We Need,’ ” study the service published last September.

Wilson also said that while the Air Force “isn’t going to get any new B-52s,” AFGSC might still take “one or two more out of the boneyard.” He noted that Ray has “already brought one B-52 out of the boneyard.”