Northrop Grumman Corp. is building two test versions of the U.S. Air Force’s newest stealth bomber, the B-21 Raider, at its Aircraft Integration Center of Excellence in Palmdale.According to an interview with Randall Walden, director of the Air Force Rapid Capabilities Office published in the January issue of Air Force magazine, the first Raider is expected to be completed early next year and perform its first flight by the middle of the year.The first Raider hasn’t yet reached final assembly, he said, but is “really starting to look like a bomber.” The second plane, now moving down the production line, will allow the Air Force to vet the airframe, Walden said in the interview. “The second one is really more about structures, and the overall structural capability,” Walden added in the interview. “We’ll go in and bend it, we’ll test it to its limits, make sure that the design and the manufacturing and the production line make sense.”Northrop’s workforce at the Palmdale facility located at U.S. Air Force Plant 42 uses cutting-edge technologies, including augmented and virtual reality, to drive innovation in advanced manufacturing to build a producible and maintainable 21st Century bomber, the company said in a release. “Our early and continued investment in infrastructure, design maturation, risk reduction and our workforce has been a significant driver of progress on our first two aircraft on the production line in Palmdale,” Steve Sullivan, vice president and general manager, strike division, at Northrop, said in a statement. “As a result, we are well-positioned for low-rate initial production following key milestones in 2022 and beyond.”In the Air Force magazine interview, Walden said that lessons learned from producing the first model are being applied to the second. That’s due to workers figuring out “how to build the airplane,” which is more than just “how the drawing tells you to put it together.” Walden said, “Space is being created” on the line for more airplanes as the first two take shape. “It’s looking pretty good,” he added. “We’re very pleased with the … very high percentages of efficiency” in building the second aircraft, “as compared to No. 1.”Northrop began design and build work on the stealth bomber more than five years ago. The aircraft’s design was proven stable and mature through a critical design review completed in November 2018 at the company’s Manned Aircraft Design Center of Excellence in Melbourne, Fla.As the program continues, Northrop and the Air Force are continuing their collaboration to provide the long-range penetrating strike aircraft the nation needs, the company said.“The B-21 Raider is the product of a proud partnership between Northrop Grumman and the U.S. Air Force,” Sullivan said in his statement. “We are committed to delivering the world’s most capable, technologically advanced bomber that will equip our warfighters with every strategic advantage against our adversaries.”The Congressional Budget Office in 2018 said that the Air Force estimated the cost of developing and buying the first 100 B-21s at $80 billion in 2016 dollars. In his interview, Walden said the program is working with B-21 vendors to mitigate the effects of the coronavirus on the bomber’s schedule. “The pandemic has slowed us in certain areas, but I think we have compensated,” he said in the interview. “I don’t think we’ve got significant delays to … first flight. Suppliers across the country are actively delivering parts to Palmdale and we’re doing what we can to help in that regard.” The B-21 Tier 1 suppliers include BAE Systems Inc., the U.S. subsidiary of British aerospace and defense company BAE Systems plc; GKN Aerospace in St. Louis; Janicki Industries Inc. in Sedro-Woolley, Wash.; the avionics and mission systems divisions of Collins Aerospace in Cedar Rapids, Iowa; and Spirit AeroSystems Inc. in Wichita, Kan.