Next in line with the USAF stealth bomber series is the B-21 which has a lot of improvements compared to its predecessor. Recently, tests of B-21 avionics and other systems revealed that the stealth bomber is working well.

Now more than ever, the development of the B-21 is getting high priority from Washington. Aspects like the airframe are getting done, as well as the testing of its avionics and software, with a related subsystem on a prototype aircraft according to Breaking Defense.

Mark Esper, Defense Secretary, said that despite challenges of getting the components for it, the B-21 Raider is on track. The head of the Air Force Rapid Capabilities Office (RCO), Randy Walden, remarked that progress is steady on the project.

He added that progress on the software that will be used to fly the plane and all the integration is going steady. These remarks were given in a conference at the Mitchell Institute.

Walden added that the first jet to be tested is almost done, with every component needed to complete the first craft of its kind. Next will be flight testing of the prototype. All the aspects of the design to manufacturing the components are getting perfected when the prototype increases production.

Critical for the plane's performance is the task of designing and testing the subsystems, with agile software tools that will seek out the flaws and correct them.

General Timothy Ray, head of Air Force Global Strike Command, said that the B-21 will be  ready for service by 2025. The Department of Defense is not giving an exact date when the plane will be operational and capable.

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The Air Force also mentioned the F-35 Joint Strike Fighter program, that was affected by the concurrence of the production and the development of other systems.

Richard Aboulafia, a long-time aircraft analyst for the Teal Group, says that it is a promising approach. There have been instances when some aspects of building, testing systems, and redesigning did not work out so smoothly like the B-1 program. Some bugs need to be worked out with agile software development.

In 2011, David Venlet, Vice Admiral and head of the F-35 JSF development, mentioned the concurrency that occurred during the program as a miscalculation. This was revealed by Mark Gunzinger, director of future aerospace concepts and capabilities assessments.

The Breaking D said that the F-35 development differed from the B-21 because it was more of integration compared to invention. Getting to lessen the costs and time involved in other relevant developments is vital too. Some examples to consider are other factors like how developed tech is, including parts for other weapon systems. Compared to the F-35 or the B-2, the B-21 is more developed at this stage.

According to Walden, the B-21 program office is using another method, DevSecOps, which adds all kinds of software to the system. As the B-21 avionics software is tested, there are still bugs to fix before the final flight. 

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