B-21 Ground Test Airframes Join Flying Pre-Production Raider
The U.S. Air Force and Northrop Grumman have expanded testing of the B-21 thanks to two ground test articles, which are being used to evaluate the bomber’s core construction and the time it takes before certain parts break. The tempo of flight testing of the initial pre-production Raider is also growing, with the jet now sometimes taking to the skies twice a week. The Air Force is otherwise continuing to lay the groundwork for fielding the first operation B-21s toward the end of the decade.
The Air & Space Forces Association hosted a panel on the B-21 today as part of its main annual conference just out of Washington, D.C. Air Force Gen. Thomas Bussiere, head of Air Force Global Strike Command (AFGSC), and Maj. Gen. Jason Armagost, the commander of Eighth Air Force, along with William “Elvis” Bailey, the Director and Program Executive Officer of the Air Force’s Rapid Capabilities Office (RCO), and Tom Jones, President of Northrop Grumman’s Aeronautics Systems sector, offered updates about the Raider. The Air Force also released new official flight test footage of the B-21, seen below, alongside the panel discussion.
“We’ve completed structures testing for our first ground test vehicle,” RCO head Bailey announced. “Now, what really we were doing there was proving out the structure, you know, of the platform, and also, at the same time, too, validating that digital model that we’ve been working on throughout – trying to understand analytically how the aircraft’s going to perform, then testing it and testing it physically, then going back to that model.”
The structural ground test article is also referred to as G-1.
“We’re doing fatigue testing on another ground model, as well, and we’ll be getting into, you know, how does the aircraft age over time,” Bailey continued. “It’s just not as flashy as the flight test crowd is, however, if you intend to build a lot of these and operate them for a long time this is very important work.”
When it comes to the first flying B-21, or T-1, “we’re going through and expanding that operating envelope for the aircraft, leading our way into follow-on system testing, for sure, learning as we go there,” the RCO head added. The Air Force ultimately expects to take delivery of six pre-production B-21s. The full Raider force is eventually expected to consist of at least 100 aircraft.
“We’re actually able to generate two test flights, sometimes, week-in-week … that’s great,” Northrop Grumman’s Jones elaborated. “When we started this journey, way back at contract award, we made a vow that we were going to design this system to be a daily flyer.”
“Clearly, I think we’re well on our way to delivering that kind of asset,” he added.
Jones said that the B-21 program continues to meet its affordability and schedule targets, but did not elaborate. He added that testing to date has proven the company’s digital modeling of the B-21 and its capabilities to be highly accurate.
“Everything we’ve heard is it flies very much like the model. In fact, a funny story I like to tell about the first flight. We’re all very excited to hear from the test pilot… he said ‘it’s almost exactly like the model, but we noticed on takeoff, it rotated slightly differently,” Jones recalled. “So engineers being engineers, they didn’t want their model to be wrong. So they pulled off all of the recorded data and looked at it and went back to the test pilot… [to] say, ‘actually, you kind of double-pumped the stick, and when we put that into the simulation it performed exactly the way the simulation said it would, so the model itself is very good.'”
“Overall, I am pleased to see the performance of our test jet. The handling qualities are better than expected coming out of the simulated environment – validating the accuracy of the digital models the team has developed and analyzed over many years,” Chris “Hoss” Moss, a Northrop Grumman B-21 Raider test pilot, said separately in a statement in a press release the company put out today.
Northrop Grumman and the Air Force have both cited the importance of highly accurate models and digital engineering techniques in the development of the B-21 since the initial contract was awarded back in 2015. This has continued in spite of growing criticism that digital engineering’s benefits have at least been over-hyped, in general, a viewpoint that the current Secretary of the Air Force Frank Kendall has himself espoused.
When it comes to the B-21, Jones also said that digital engineering had helped reduce risks associated with concurrency, which refers to a system entering production despite the design not being completely finalized in many respects. The pre-production B-21 configuration is understood to be very close to that of the first production examples in large part thanks to modeling done earlier in development.
“If you are around acquisitions a lot, and you heard someone say, ‘we’re in tests and also in production,’ a lot of people would start worrying about something we concurrency, right,” Jones explained. “And that’s something that, traditionally, there’s been a lot of risk in, but I believe the digital engineering environment… and the… contract management’s allocation of risk mitigation actions we’ve done in concert with RCO has really been able to manage down risk.”
Jones added that Northrop Grumman views the modeling for the B-21 to be accurate enough to directly inform test points and overall test planning and that it is now also factoring into the initial low-rate production of the bombers.
“This is the way we’re going to build things. We’re retroactively putting it into other systems that we build. And I can’t imagine going forward in any future designs or builds not adopting this type of … highly integrated digital model to shop floor methodology,” the Northrop Grumman executive said.
The philosophy Jones described has also already been observed in the creation of the Model 437 Vanguard technology demonstrator jet by Northrop Grumman subsidiary Scaled Composites. Colin Miller, Vice President for Engineering within Northrop Grumman’s aeronautics sector, highlighted the influence digital engineering techniques from the B-21 program had on the Model 437 project in an exclusive interview with The War Zone on the latter aircraft that you can find here.
Beyond digital engineering, “in terms of advanced manufacturing, there’s a lot of different techniques we’re using. We’re using robotics in a number of different places, from… automated fiber layup, in some cases, to automated robotic non-destructive inspection. So we’re finding ways to build efficiency in there,” according to Jones. “One of the areas that has produced some of the most gains is augmented reality. Started out basically just wanting to use augmented reality to get the shop floor instructions [to] where basically the technicians can see them as they’re doing the operation and not have to run back and forth to the desk to consult drawings… And we realized, hey, we can superimpose subsystems and wiring and hydraulic tubing on there and speed up subassemblies.”
In addition to the ongoing development and production of the B-21s themselves, the U.S. Air Force is also improving infrastructure, training personnel, and working on tactics, techniques, and procedures to help get ready to actually field the first operational Raiders. Ellsworth Air Force Base in South Dakota is set to host the first operational squadron of the bombers, followed by units at Whiteman Air Force Base in Missouri and Dyess Air Force Base in Texas.
“You can get on Ellsworth Air Force Base, just drive around and look, it is a substantial lift is what is happening. It’s impressive and it is similar to the aircraft itself,” Maj. Gen. Armagost said. “It’s falling on that wing [28th Bomb Wing]. It’s falling on the airman. It is falling on the contractors who join with us and partner with us to really make that happen. It’s quite impressive.”
“What we have done is modeled what we were calling the ‘farm team’ as led through the mighty Eighth Air Force, but also directly led through the 31st Test and Evaluation Squadron at Edwards,” Armagost continued. “And we are gathering from around the Air Force instructors who are experts in their systems and we’re bringing them together along the model of operators with industry and acquirers to develop TTPs [tactics, techniques, and procedures] to understand differently how we’re going to use this penetrating system, this sixth generation penetrating system, in a way that we have to work our way through so that when we have it on the ramp at Ellsworth Air Force Base, we’re ready to do that.”
“We’re trying to be very ahead of how we might actually deploy this airplane. And I would say that’s what’s different about the B-21 from the B-2,” Armagost continued. “I think we learned some lessons early on in the B-2 program that maybe we could have done it slightly differently along these lines.”
By all indications, the Air Force, together with Northrop Grumman, is making progress in not just getting its hands on its first production B-21s, but having them in operational service in the 2030s.
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