Is the B-21 bomber a viable option for Australia?

Australia needs to consider its options for projecting greater military power in an age where we can’t assume that we’ll get assistance from the US whenever and wherever we need it.

In my recent Strategist series on projecting power with the F-35, I looked at options to overcome the jet’s inherent range limitations so it can project further into the vast expanses of the Indo-Pacific. It can be done to some extent, but all scenarios require large-scale investment in enabling capabilities—ranging from air-to-air tankers to off-shore bases—as well as capabilities such as ground-based air defence to protect it.

I’d planned to examine the full range of strike options before unveiling the punchline—namely, the B-21 Raider strategic bomber. But since ASPI analyst Catherine McGregor has reported that two former air force chiefs think we need strategic bombers, I’ll cut to the chase and look at whether that’s a viable option.

As context let’s review some history. Australia has operated long-range bombers in the past—the ‘G for George’ Lancaster bomber occupies pride of place in the Australian War Memorial. In the European theatre in World War II, the RAAF flew Halifax, Wellington and Lancaster bombers, and it also operated long-range strike aircraft including B-24 Liberators in the Pacific.

In the post-war period, Australia operated the Canberra bomber. The Canberra’s range was limited and it was replaced with the F-111C, which had a combat radius of over 2,000 kilometres as well as the ability to be refuelled mid-air. That put Jakarta within its range, and while it’s debatable whether Australia would have ever considered bombing our neighbour’s capital, the capability itself certainly got the Indonesians’ attention. And that’s the point of high-end strike capabilities—they act as a deterrent and shape others’ thinking even if they’re never used.

So we’ve recognised the need for long-range strike aircraft before. Today there aren’t many options for a strategic bomber. Unless we acquire used US B-52, B-1 or B-2 bombers (all of which would come with a serious downside), the only option is the B-21 being developed by the US Air Force (Unmanned systems are potentially another option, but there’s nothing out there right now.) There’s not a lot of information available about the B-21, but the USAF’s intent seems to be that it will be at least as capable as the B-2.

That suggests it will have an unrefuelled combat radius of around 5,000 kilometres. As shown in the figure below, that would allow it to operate from deep within Australia (I’ve used Alice Springs to illustrate the point) and still cover the entire archipelago to our northwest, the South China Sea, our South Pacific neighbours, and the gap between Guam and Papua New Guinea.

Figure 1: 5,000-kilometre combat radius from Alice Springs

Because of its inherent range, the B-21 wouldn’t require air-to-air refuellers. Being based well inland, it wouldn’t be exposed to the same extent to the threats that our northern bases or offshore airbases are faced with. A strike platform like the B-21 would still require sophisticated enablers to find and precisely target an adversary in that huge combat radius. Those come at a substantial cost.

The B-21 could deliver a broad range of effects. A strike package of four aircraft could likely carry around 40–50 long-range maritime strike weapons, which would inflict unacceptable losses on any maritime or amphibious task force. If the target was the adversary’s forward operating bases, a first wave of aircraft could use long-range stand-off weapons to destroy their air defences (including aircraft on the ground), with each bomber in a follow-up wave delivering around 80 precision-guided  JDAM (Joint Direct Attack Munition) bombs, or around 200 small-diameter bombs.

Moreover, the bombers could return the next day, unlike a submarine which could need a month to return to the fight after going home to reload once it had launched its handful of strike missiles. No other system could deliver a comparable weight of fire. It would certainly get the attention and shape the military planning of any power that wanted to operate in that huge circle.

The B-21 could also be used tactically to deliver close air support to Australian and allied troops on the ground, as US bombers have done in the Middle East. A single B-21 could carry about as much ordnance as a squadron of F-35s but with greater range and persistence over the target and fewer enablers.

But it wouldn’t be able do everything. A B-21 won’t perform anti-submarine warfare in the same way as the ADF currently does it with a combination of ships, submarines and aircraft. But it could do it in a different way—for example, by striking enemy submarines in port or by air-dropping smart sea mines off those havens or in key choke points.

Based on public information, it’s possible that Australia could get aircraft into service in the second half of the 2020s. So it couldn’t happen overnight, but it’s certainly faster than even the most optimistic future submarine schedule.

Of course, that great capability comes at a great cost. The USAF is aiming at a unit cost of US$564 million in 2016 dollars. That’s if it can get the 100 aircraft it wants and escape the death spiral of other programs like the B-2 and F-22, which cut production numbers to reduce program costs. That drove up unit costs, which in turn forced cuts to projected unit numbers. So we would probably be looking at a cost of around A$1 billion per aircraft.

It’s hard to know how many we’d need for a viable capability. The RAAF acquired 24 F-111Cs, followed by 15 F-111Gs, but at retirement there were only 13 left in service. The USAF is operating a fleet of 20 B-2s. Let’s assume the sweet spot is around 12 to 20 aircraft. Since total program costs are usually around 1.5 to 2 times the cost of the aircraft themselves, we’d be looking at around $20–40 billion. That’s a lot of money, but less than the cost of the future submarine program.

The real challenge is always affording the annual cash flow without gutting the defence budget. Unlike the future submarine program, which is drawn out over nearly 40 years, the bulk of the spending to acquire the B-21 would likely be compressed into five or six years, requiring around $5–6 billion per year. That’s over half of Defence’s capital equipment budget. And it’s more than the entire local shipbuilding program when it is up and running (which has been declared untouchable).

It’s hard to see Defence being able to afford that without a massive cash injection from the government. But if the government is serious about addressing our worsening strategic environment, the B-21 would be an investment that made both friends and potential adversaries sit up and take notice.