WASHINGTON — The US Air Force's new B-21 bomber stealthily hit a milestone recently, wrapping up its preliminary design review.

During a House Armed Services Committee hearing on nuclear deterrence, Gen. Stephen Wilson, the Air Force's vice chief of staff, told lawmakers that he receives regular updates on the uber-classified program and is happy with its progression.

"They just finished a preliminary design review recently," he said. "It's making great progress, and we're pleased with the way it's headed."

The Air Force awarded Northrop Grumman a contract to develop and produce the B-21 Raider in October 2015. The company beat out a Boeing-Lockheed Martin team, a decision that was sustained even after the losing competitors filed a protest with the Government Accountability Office.

Since then, however, news about the B-21 has been thin on the ground as the Air Force tries to protect any information about the bomber’s design and development from leaking out into the press — or to potential adversaries’ hands.

The service has not disclosed the total value of the contract awarded to Northrop, but it estimates the aircraft will cost about $550 million per copy. Last year, Randall Walden, who heads the office charged with acquiring the Raider, said the company is on track to beat that number.

The first aircraft are projected to go into service in the mid 2020s.

In February, Defense News reported that the Raider will likely receive its stealth coating at the same "Air Force Plant 42" facility in Palmdale, California, that is used for the B-2’s final checkout and stealth coating repairs. Northrop received a $35.8 million contract modification in January for construction of a new 45,900 square foot coatings facility at that location.

Walden in June also mentioned that Northrop was hiring personnel at its Melbourne, Florida, location to work on the bomber.

Aaron Mehta contributed to this report.

Valerie Insinna is Defense News' air warfare reporter. She previously worked the Navy/congressional beats for Defense Daily, which followed almost three years as a staff writer for National Defense Magazine. Prior to that, she worked as an editorial assistant for the Tokyo Shimbun’s Washington bureau.

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