On 18 April 1942, four months after Pearl Harbor, eighty airmen in sixteen B-25 Mitchell bombers under Lt. Col. James “Jimmy” Doolittle flew off the deck of the USS Hornet and bombed Tokyo and other Japanese cities — then pressed on toward China, where most crews crash-landed or bailed out. Militarily the damage was slight; psychologically it was enormous, proving Japan’s home islands were not beyond reach and lifting American morale at its lowest point.

The Air Force revived the name in September 2016. Retired Lt. Col. Richard “Dick” Cole — Doolittle’s own co-pilot on the lead aircraft and, at 101, the last surviving Raider — helped reveal it. Cole died in 2019, aged 103. The choice is deliberate: like the men it honours, the B-21 is built to reach targets others believe are safely out of range.

Every straight edge, every gap and every exposed engine face is a place a radar can find an aircraft. A tailless flying wing removes most of them: there is no vertical fin, no sharp fuselage, just a single continuous blended shape whose few edges are aligned to scatter radar energy away from the receiver. The B-2 proved the idea in the 1980s; the B-21 refines it with three more decades of low-observable materials and, reportedly, broadband shaping intended to defeat the lower-frequency radars that modern air defences increasingly use to hunt stealth aircraft.

Northrop has said little in specifics — signatures, coatings and inlet design are among the programme’s most closely held secrets. What officials will say is comparative: at the rollout, the Secretary of Defense claimed even the most advanced air-defence systems “will struggle to detect a B-21 in the sky.” The honest caveat is that no outside observer can verify that; the numbers that would prove or disprove it are classified.

The Raider is the flagship of what the Air Force calls digital engineering. Before metal was cut, Northrop built a complete virtual aircraft — a “digital twin” — and its hundreds of suppliers worked from a shared model rather than paper drawings, so that parts fit and systems behaved as predicted when the real airframe came together. The intent was to wring surprises out in software, where they are cheap, instead of on the flight line, where they are not.

The pay-off shows in an unusually undramatic flight-test campaign and in the aircraft’s open mission-systems architecture, designed so new weapons and sensors can be integrated as software loads over the type’s life. Whether digital engineering truly tames the cost and schedule risk that has haunted every past bomber is still being tested — but the B-21 is the biggest bet yet that it can.

The B-21’s defining promise is that stealth can be affordable. The Air Force built the programme around an average procurement unit cost of about $692 million per aircraft in 2010 dollars — a figure that rises in then-year money but is still a fraction of the B-2’s roughly $2 billion. The full programme is estimated at $203 billion or more across development, at least 100 aircraft and thirty years of operations.

Affordability has not been painless. Northrop Grumman took charge of roughly $1.6 billion against the first low-rate production lots in 2023–24, when fixed-price contracts collided with inflation. The Air Force has since reported the costs under control after renegotiation, and its fiscal-2027 request for the programme runs to about $6.1 billion as it accelerates production. A true cost-per-flight-hour will not exist until the fleet actually operates — which is why the specification above leaves that line open.

The stated floor is 100 aircraft, and senior officers and analysts have argued for more — studies have floated 145 to 200 to give the force real depth against a Pacific adversary. Production is being accelerated toward a target of roughly seven aircraft a year, with capacity recently expanded.

Flight testing runs at Edwards Air Force Base, California, where the 412th Test Wing’s B-21 Combined Test Force flies the aircraft; a second airframe joined the effort in September 2025. Ellsworth Air Force Base, South Dakota, will host the first operational and training units — Air Force leaders expect Raiders “on the ramp” there in 2027 — followed by Whiteman AFB, Missouri and Dyess AFB, Texas.