Defence manufacturer Northrop Grumman is preparing a series of modernisations for the company’s iconic B-2 Spirit flying wing bomber, including changes to aircraft’s exterior radar absorbent coating.

Although the next-generation B-21 Raider stealth bomber Northrop is developing for the US Air Force (USAF) receives more public focus, the company is continuing to churn out improvements for the small fleet of B-2s – currently the USAF’s only bomber that is both stealthy and capable of carrying nuclear weapons.

“We have a small fleet and an ageing fleet,” says Nikki Kodama, Northrop’s B-2 programme manager. She spoke with FlightGlobal on 12 September at the 2023 Air Space Cyber (ASC) conference near Washington, DC.

The USAF famously cut its acquisition of the ultra-expensive B-2 to under two-dozen aircraft. The service currently operates a fleet of just 20 Spirit bombers, which were valued at $1.15 billion per aircraft in 1998-dollar terms, according to the Pentagon.

“As we’re dealing with obsolescence or supply issues, it is a little more challenging when you’re talking about small quantities of procurement,” Kodama says of the 30-year-old bomber, the first example of which was delivered to the USAF in 1993.

“It’s something that we are actively working with the air force to address.”

The revolutionary stealth bomber, which was the first to incorporate the radical flying wing design that will also be a feature of the B-21, is notoriously difficult to maintain. Certain access panels can only be opened by scraping off the B-2’s specialised radar absorbent coating, which must then be carefully reapplied.

B-2 Azores

Source: 65th Air Base Group/US Air Force

Despite its small fleet size, the B-2 Spirit stealth bomber has proven to be a key tool of the American global security infrastructure, with recent appearances in the Azores and Iceland

That experience is influencing the B-21 design, with an eye toward making the Raider a so-called “everyday flier”. But new B-21 components are also finding their way into the older B-2, which Kodama says is an effort to lower sustainment costs and increase the lifespan of the ageing Spirits.

An early example of that technology sharing involves mission planning software Northrop developed for the B-21 that will also be compatible with the B-2 – allowing the two bomber types to integrate more easily.

“We can actually share applications that were developed for the B-21 on to the B-2,” Kodama notes.

The new software has been separated from the B-2’s flight control software, meaning new applications can be tested and fielded much faster.

As an added benefit, Northrop will be able to operationally test its B-21 systems on currently-flying B-2s, rather than waiting for the Raider’s upcoming flight test programme.

The USAF is not saying much about its future plans for the B-2. Service leaders are committed to acquiring at least 100 B-21s, which they say will replace both the Spirt and the Boeing B-1B conventional heavy bomber.

However, with the Raider not expected to make its first flight before late 2023 or even 2024, it will be years before the USAF has a fully-operational fleet of B-21s.

The service’s Global Strike Command (GSC), which oversees bomber operations, says the B-2 will continue to serve until the B-21 reaches that milestone.

“We do not plan on divesting any part of that fleet until we have this [B-21] capability proven,” said Brigadier General Ty Neuman on 13 September.

Neuman, who is GSC’s director of strategic plans and programmes, also spoke at ASC.

Kodama says the B-2 is more than capable of filling that gap “far into the future”. The physical airframe is projected to remain mission ready into the 2050s.


Source: Northrop Grumman

Maintaining the B-2’s radar absorbent coating has proven to be a costly and labour-intensive process. Northrop Grumman hopes a change of material could reduce annual maintenance requirements by thousands of hours

Northrop’s modernisation efforts are intended to keep the rest of the aircraft ready to fly on a 21st century battlefield with contested airspace. Kodama reveals the effort is focused on four principal areas: communications, lethality, survivability, and supportability.

“That is what will not only keep the B-2 mission ready, but also mission relevant,” she says.

Without offering specific examples, Kodama says that includes integrating some of the USAF’s latest long-range precision weapons into the B-2.

“We’re looking for flexibility in loadouts that we’ll be able to bring to the B-2 and the integration of new advanced weapons,” she notes.

Northrop and the USAF in 2022 successfully test fired a Lockheed Martin AGM-158 Joint Air-to-Surface Standoff Missile (JASSM) from a B-2. The stealthy cruise missile is viewed as a critical capability – along with the JASSM-derived Long Range Anti-Ship Missile – in any potential conflict with a near-peer adversary like Russia or China.

Also critical in such a scenario is the ability of friendly aircraft to slip undetected past advanced airspace monitoring radars. While the B-2 possesses this ability, maintaining that stealthy profile has proven costly and time-intensive.

Northrop is currently in the process of testing improvements to the bomber’s radar-absorbent surfaces, which the company says will drastically reduce the maintenance needed to maintain the low observable (LO) coating.

The change involves phasing out the use of radar-absorbing tape, in favour of a coating material known as magnetic radar absorbing material, or MagRAM.

The specialised tape must be regularly applied to certain B-2 surfaces in order to maintain the aircraft’s LO profile. Kodama says after analysing B-2 maintenance records, Northrop found the tape to be a “high driver” of time needed to preserve mission readiness.

“Using MagRAM, instead of tape, we are driving down maintenance and man hours to maintain that LO,” she notes. “It’s keeping LO health on the aircraft and making it a more maintainable platform.”

Kodama reveals Northrop is in the process modifying the first B-2 with the new MagRAM tape replacement. The company expects to complete the physical modifications before year’s end. 

Northrop hopes to expand the programme, which it calls MagRAM Over Conductive Surfaces, to the entire B-2 fleet.

Kodama says the change could reduce the annual maintenance requirement for the B-2 fleet by “tens of thousands” of hours.

The USAF says it expects the first B-21 to enter service sometime in the “mid-2020s”. That means the air force will still be relying on its size-limited B-2 fleet for the foreseeable future.

Kodama says Northrop will continue to work with the USAF on increasing the type’s lethality and capability, including the possibility of teaming the B-2 with autonomous combat jets being developed under the Pentagon’s recently announced Replicator initiative.

“The platform itself is highly capable,” she says. “It’s just about how much you want to modernise it and continue to invest in it.”