B-21 Raider Final Assembly Facility, Air Force Plant 42, Palmdale

The B-21 Raider final assembly facility at Air Force Plant 42 in Palmdale, California, adds more than 1 million square feet of production space to the site where the Air Force’s new stealth bomber is built. The Air Force and Northrop Grumman broke ground on Sept. 29, 2026, and announced it about a week later.

The building is the physical half of a February 2026 agreement between the two to raise annual B-21 production capacity by 25%. It’s backed by $4.5 billion authorized and appropriated through fiscal 2025 reconciliation legislation. Northrop CEO Kathy Warden separately disclosed in April that the company would put $2.5 billion of its own money into added B-21 capacity, according to The Aviationist. None of the published sources breaks out what the new facility itself will cost.

Project Scope

Here’s what’s public: a new final assembly line of more than 1 million square feet, at a government-owned plant where multiple Raiders are already in various stages of production. That’s close to the whole list. No builder, architect or engineer has been named, and there’s no completion date. Construction Dive’s coverage, citing an Oct. 8 release, didn’t identify a general contractor either.

That’s normal for classified aerospace work. Plant 42 is a large Air Force-owned complex in the Antelope Valley that has hosted military aircraft production for decades, and little of what goes on inside its fences gets described in public.

The size still tells builders something. A million square feet of final assembly space will likely mean long-span high-bay structure, heavy slabs and the security and environmental systems that come with low-observable aircraft work.

Why It Matters

The program of record calls for at least 100 bombers, and the first operational aircraft is due at Ellsworth Air Force Base, South Dakota, in 2027. A 25% capacity increase pays off only if the Air Force buys more than the baseline or wants them sooner, and it hasn’t formally committed to buying more.

Col. Nicholas Jordan, the B-21 program director, said the Palmdale investment would supply the infrastructure, workforce and manufacturing capacity to deliver the Raider at a higher rate. Air Force Secretary Troy Meink was blunter: “It’s more than construction … we’re moving fast to build B-21s!”

The groundbreaking lands in a busy stretch for defense industrial construction, with new shipyards and munitions plants starting across the country. Contractors who can clear security and staff a desert site at scale should expect more of this work, even if they can’t put it on their websites.

Project Team & Details