The B-21 left Northrop's facility at the Air Force's Plant 42 in Palmdale, California, at sunrise on Friday offering the first unscripted look at the new bomber which has been developed under strict security.

The plane took off just before seven in the morning, according to a Reuters witness.

The B-21, which carries the same "flying wing" shape of its predecessor, the B-2, will be able to deliver both conventional and nuclear weapons around the world using long-range and mid-air refueling capabilities.

The aircraft are projected to cost approximately $550 million each in 2010 dollars, or about $750 million in today's inflation-adjusted dollars. However, the Air Force has kept other price information classified, "which makes validating the proposed cost difficult," the Congressional Research Service said in a 2021 report.

The Air Force plans to buy at least 100 of the planes and begin to replace B-1 and B-2 bombers. The B-1 costs about $60,000 per hour to operate and the B-2 costs about $65,000 per hour, according to Pentagon data.

Northrop beat out a team comprised of Boeing Co and Lockheed Martin Corp when it won the 2015 contract to make the bomber. Engine-maker Pratt & Whitney, Collins Aerospace, GKN Aerospace, BAE Systems and Spirit Aerosystems are among the more than 400 suppliers in 40 states.

The B-21 was publicly unveiled in December 2022, but anticipation surrounding its first flight has been building for years.

(Reporting by David Swanson in Palmdale, California and Mike Stone in Washington, Editing by Franklin Paul)

By Mike Stone