The Air Force decided to cancel a major defensive upgrade to its B-2 stealth bomber in the fiscal year 2021 budget request after realizing that new software code wouldn’t work with the legacy embedded computer systems on the aircraft without further delays and costs, a senior Air Force official told a House panel last week.

The lesson learned with the Defensive Management System Modernization (DMS-M) program is that “if we want to do a major modernization in the future and deploy onto old computers, the embedded systems are going to eat our lunch,” Will Roper, assistant secretary for Acquisition, Technology and Logistics, told the House Armed Services Subcommittee on Seapower and Projection Forces. “And as long as we’re maintaining old systems, it’s something that’s going to bite us if we have to keep it relevant.”

The Air Force spent $1.9 billion on the DMS-M modernization but after various delays, some which included using agile software development to speed the introduction of software code, the service found that even with Northrop Grumman [NOC] developers writing good code “nuances on the jet were unknown and now they have to debug them, they have to work regression testing and that drove a lot more time because the upgrade is significant,” he said.

Northrop Grumman is the prime contractor for the B-2.

While too late for the DMS-M upgrade, Roper said that there is “good news” going forward with a new open source software platform technology called Kubernetes that “in a nutshell it ensures the code runs the same way bit for bit on any kind of computer.” The Air Force has demonstrated the technology on the F-16 fighter, he said.

“Unfortunately, it was a technology that wasn’t trending when this program began and we’ve learned a lesson the hard way but it’s a lesson I don’t intend to learn again,” Roper told the panel.

Rep. Rob Wittman (R-Va.), the ranking member on the subcommittee, reminded Roper that a year ago he had said the Air Force can’t take a risk with the program because it needs the B-2 to be able to penetrate enemy air defenses.

Lt. Gen. David Nahom, the Air Force’s deputy chief of staff for Plans and Programs, appearing alongside Roper, replied that the B-2 will still be be able to do what the nation needs until it heads toward retirement in a decade.

“There were also some difficulties in the program,” Nahom said of the DMS-M. “But when we look at that, we actually have ways we think we can mitigate that and what I would like to do is come back in a classified setting and talk more specifically about that because I think there’s ways we can save money and apply that to B-21 and B-52 modernization and mitigate that risk in the interim.”

In response to a question from Rep. Vicky Hartzler (R-Mo.) about upgrades to the B-2 that are still planned, Roper mentioned that still funded are the flexible strike upgrade, a military GPS upgrade, a common VLF receiver, a new aviation transponder, a crash survivable memory unit, a radar aided targeting system, integration with the Joint Air-to-Surface Standoff Missile, and signature and low observable maintenance and improvements.

The Air Force currently operates three strategic bombers: the B-1, the B-2 and the B-52. The future bomber force will consist of the B-21 that Northrop Grumman is developing and a “heavily modified B-52,” Nahom said.

One of the major upgrades planned for the B-52 is a reengining effort. A Request for Proposals for the new engines will be released this year, Roper said.

Other upgrades to the B-52 included new radar and digital backbone, Nahom said.

The long-range, subsonic B-52 has been operating since 1952 but Nahom said that the aircraft are “relatively young in terms of flying hours” largely because they were on alert during the Cold War, Nahom said. The supersonic B-1 bomber, which was introduced to the fleet in the mid-1980s, suffers from overuse, is beyond its service life and is “broken in many ways,” he said.

Using the same number of maintainers on a smaller B-1 fleet should get the aircraft to acceptable mission capable rates, Nahom said.

The Air Force plans to retire 17 B-1s so that it can put its operations and maintenance focus on 44 remaining bombers until they are retired, Nahom said. The goal is to keep the B-1s around until the B-21s begin their basing in the 2026 to 2027 timeframe, he said. The B-21 won’t be nuclear certified for another decade, which is when the B-2s will begin to be retired, he said.

The last B-1 will be around until the late 2020s or early 2030s, Nahom said, noting that there are too many variables to be specific.

Until the B-21 is ready, the B-2 provides the ability the penetrate enemy air defenses combined with its “strategic deterrence mission” and the B-1 offers “just pure volume of fires,” Nahom said.

If the B-21 gets delayed, Roper said the Air Force has to keep in mind the potential to invest more in the B-1 “to preserve long-range strike.”