Northrop Grumman adds second B-21 ground test article

The Northrop Grumman B-21. (Northrop Grumman)

The Northrop Grumman B-21 test fleet has expanded to three aircraft: one test-flight aircraft and two for static tests on the ground, Tom Jones, president of Northrop Grumman's aeronautical sector, said at the Air & Space Forces Association's (AFA's) Air, Space, and Cyber conference in National Harbor, Maryland, on 18 September.

The second ground-test aircraft joins tail number G-1 in static testing. Janes was unable to confirm further information about the new test aircraft's identity or its use in testing; it is likely one of the six revealed as under construction at Northrop Grumman's Palmdale, California, factory as of 12 November 2023, when B-21 tail number T-1 conducted the type's first flight.

Although the type entered low-rate initial production (LRIP) as of 22 January, it is unclear how many B-21s are under construction today. When the next example is scheduled to enter flight test has not been publicly disclosed.

Northrop Grumman deferred questions to the US Air Force (USAF), which declined to comment.

Tail number T-1 performs up to two test flights per week, said Jones, performing almost exactly as digital models suggested it would in the air. Northrop Grumman employed digital models extensively on the B-21, testing how parts interacted using a “digital twin”, or exact digital replica of the aircraft, before constructing parts. A 2021 Congressional Research Service report also noted the type's relatively high technical maturity, implying that major subsystems were built and tested well before the bomber's roll-out.