Projecting Power with the F-35 in the Direct Defense of Australia


By Marcus Hellyer

One of the ironies of the current debate about how Australia should adjust its military strategy in light of the changing great-power balance in the Indo-Pacific is that many of the participants—regardless of their views on the future of US military power—make similar recommendations, namely, that Australia should seek greater defence self-reliance.

This would be achieved by capability solutions based largely on ‘more of the same’. That is, to meet an increasingly uncertain strategic environment, our future force structure should be built around more of the things we already have, or are getting, such as F-35A joint strike fighters and submarines (even if some advocate different submarines from the ones we’ll eventually get under the current plan).

So it’s important to understand those systems and their limitations to see what additional capability more of them would provide. Since Australia and its region are geographically far-flung, and we have only a small number of military assets, we’ll focus on their ability to maintain a presence over large distances. The key question is, to what extent do the capabilities the Australian Defence Force is acquiring enable Australia to project power and what would further enhance that power projection?

We’ll start with the F-35A.

Defence is in the process of acquiring 72, with potentially some more down the track. The F-35A is now a very capable aircraft, but it still faces the old problem that, no matter how good a military platform is, it can’t be in two places at once. And due to the inherent limitations of fighter aircraft, there are a lot of places they can’t be at any time.

Most Australians’ experience of aviation involves getting on a passenger jet in a major Australian airport and getting off on another continent, say in Los Angeles, Dubai or Tokyo. But those kinds of ranges are vastly greater than what modern fighter aircraft can achieve. This is a characteristic of all fighters; the F-35A has pretty good range in comparison to its peers.

The air force’s website lists the F-35A range at 2,200 kilometres, which is how far it can fly in a straight line. That doesn’t get the aircraft from the RAAF’s main fighter base at Williamtown in NSW to Perth (3,363 km) or Darwin (3,108 km). But since you want the pilot and aircraft to get home from the mission, its combat radius of 1,093 km is a more meaningful number than range.

There are three radii that are useful to consider in the context of the F-35A: they are (roughly) 500 km, 1,000 km and 1,500 km. The one that is most appropriate depends on the mission and how many resources Defence is able to apply to achieve it.

The ‘owner’s manual’ radius of the F-35A is essentially 1,000 km with a little margin built in to take into account real-world factors.

What does that look like in the vast distances of the Indo-Pacific or the blue continent of the South Pacific?

The map below is based on one developed by my ASPI colleague Malcolm Davis.

The red rings represent the F-35A’s combat radius operating from the six mainland airbases in Australia’s north: Darwin, Townsville, Amberley, the bare bases at Curtin and Learmonth in Western Australia, and Scherger on Queensland’s Cape York Peninsula.

1,000-kilometre combat radius from northern Australian bases

So, 1,000 km doesn’t project very far out into the vast distances of the Indo-Pacific. It doesn’t even get very far out into our South Pacific backyard.

At least from our northern bases we can cover our immediate approaches. However, the RAAF couldn’t operate all those rings simultaneously with the three squadrons on order (and a fourth made up of the Super Hornet, or whatever replaces it).

But 1,000 km doesn’t include fuel to stay on station, so while it may be helpful for understanding range for a strike mission (fly out, launch ordnance, fly home), it’s not a useful number for missions where the aircraft have to loiter—for example, protecting a deployed maritime or amphibious task force, or providing close air support to land forces.

The more time on station, the less range.

Moreover 1,000 km isn’t necessarily a representative number for air-to-air combat in which fuel consumption increases exponentially as the aircraft accelerates to combat speed or uses afterburners.

In short, an F-35A that flies out 1,000 km and fights enemy aircraft probably isn’t going to make it home, so a 500 km combat radius might be more accurate when it comes to an air defence role or one that requires some time on station.

500-kilometre combat radius from northern Australian bases

That makes a big difference.

There are now gaps between the red rings, even if we could operate in each of those rings simultaneously.

And the longer you want the aircraft to loiter on station, the smaller that radius becomes.

Moreover, it’s difficult for the F-35A to sustain a continuous presence over any land mass outside of the continent, which means a maritime task force could only be protected if it was operating very close to the Australian mainland, or, in the case of an amphibious task force, if it was seeking to deploy its land component actually on Australian soil.

Air-to-Air Refuelling

Of course, this analysis doesn’t take air-to-air refuelling into account.

Tankers can substantially increase fighters’ time on station (that is, how long they can stay out). But they can’t extend the jets’ combat range indefinitely. There are several reasons for this. The first is that generally pilots want to have enough fuel on board to get home alone, just in case the tanker they were planning to refuel from isn’t there (due to mechanical problems, being shot down or driven off station by enemy aircraft, or just running dry).

In a region like the Middle East, this risk can be mitigated by having fallback airfields to divert to in an emergency, but in the Pacific (and indeed in Australia itself) there are very few fallback options, particularly ones that you can safely land a conventional fighter on.

That means once an F-35A flies out roughly 1,000 kilometres, it needs to tank before it can go any further. But that load of fuel only allows it to go a further 500 km because at that point it will still need to have 1,500 km of fuel reserves on board to get home. And that doesn’t give any time on station or give it fuel to fight. So, it would need to tank again to stay on station.

But, theoretically, a combat range of around 1,500 km is achievable.

That would look something like the red ring in Figure 3.

1,500-kilometre combat radius from Darwin

I’ve included only one ring, and that’s because of the second reason that tankers can’t extend a fighter’s range indefinitely—air-to-air refuelling to keep fighters on station is very resource intensive.

If a commander wanted to keep F-35As on station around 1,500 km out from mainland airbases (potentially protecting an amphibious task force, a lodged land force, or a naval task force patrolling choke points), planners would likely need to set up two refuelling circuits—one to enable the fighters to reach their station, and then one a few hundred kilometres behind the fighters’ station so they can pull back, refuel and return to station with fuel to fight.

In that scenario, keeping just two F-35As on station would take at least eight F-35As in the air at one time around the clock (two heading out, four cycling between their station and the refueller, and two heading home). Each of them would need to fly an eight-hour mission, potentially tanking four or five times. Taking aircraft maintenance and unserviceability into account (which will increase as the operation continues), that would potentially require at least 12 to 16 aircraft to sustain. But since pilots can fly that mission only once per day, the cycle needs a minimum of 24 pilots (and more to account for ‘unserviceability’ of pilots as the operation grinds into the future).

But more is needed.

The whole concept of a fifth-generation air force relies on superior situational awareness, so to fully exploit the F-35A’s capabilities the package would need to include an E-7A Wedgetail early warning and control aircraft flying a circuit a hundred kilometres or so behind the fighters to detect enemy aircraft. The RAAF has six, and fewer than that will be available for operations, and fewer again serviceable for missions.

Therefore, sustaining that one combat air patrol will likely require all the Wedgetails.

Keeping them on station will likely draw on some of the tankers’ fuel.

But the biggest stressor on the viability of the mission is tanker capacity.

The air force now has seven KC-30A air-to-air refuellers after recently acquiring an additional two.

It’s hard to see more than five being available, and fewer will be serviceable on any given day. One tanker, engaged in continuously refuelling fighters on the combat air patrol, can’t stay on station for more than four to six hours before needing to refuel.

Sustaining two refuelling stations (one to get the fighters out to the patrol area and one to sustain them on station) with a force of only four or five tankers would likely exceed any responsible commander’s risk tolerance by creating a single catastrophic point of failure. One unserviceable tanker, accident or combat loss would cause the entire cycle to collapse, potentially with pilots and aircraft unable to make it home.

Keeping the fuel flowing to the tankers would also be challenging. Even exercises such as Pitch Black have taxed fuel supplies at permanent bases. The kind of scenario outlined here would require well in excess of 500 tonnes of fuel per day (visualise around 20 semi-trailers, or over the course of a month something roughly commensurate with the Northern Territory’s total average monthly aviation fuel consumption).

Getting that reliably to remote bare bases such as RAAF Scherger on Cape York would be a demanding task, although the challenge could be mitigated by flying the tankers out of permanent air bases.

A 1,500 km sustained presence over a hypothetical task force in the Bismarck Sea would look something like the smaller of the two rings in Figure 4.

F-35A combat air patrol at 1,500 kilometres

That would consume all of the RAAF’s enabling capabilities. It’s possible that enough fighter pilots and jets would be left over to conduct air defence of one other location (indicated here by the ring based on Darwin), but they’d be doing it without early warning aircraft or tankers.

Pulling the patrol back into 1,000 km would destress the cycle, potentially by allowing the commander to manage with just one air-to-air refuelling circuit, thereby requiring fewer KC-30As. But that gets us back to our starting point—air-to-air refuelling doesn’t help that much with increasing the F-35A’s combat range.

Would more of the same help?

The short answer is, it can’t extend range much beyond 1,500 km as that limit derives from the nature of the F-35A.

But more enablers would make the system robust. Andrew Davies recently gave a concise list of what these would be, ranging from greater fuel storage to tankers.

People are key—not just pilots, but also maintainers, ordnance handlers, and air combat officers in the back of Wedgetails, to name a few essential categories—but all will be taxed in a scenario of sustained operations. Even mundane things like concrete hard stands would be in high demand, because the limited space of the bare bases would quickly be overwhelmed. In short, the F-35As themselves are just the tip of the iceberg.

If the enemy has long-range standoff strike weapons or special forces that can destroy fuel farms, that’s another point of failure, as is a strike that craters the runway and shuts down operations. A favourite special forces tactic in exercises is to sneak in at night and ‘kill’ all the pilots.

So ‘more of the same’ would also need to include defensive capabilities such as ground-based air defence missiles, air defence guards, and maybe even a combat air patrol over the base itself (requiring more F-35As, more pilots and more fuel).

More fighters could allow the RAAF to operate simultaneously from multiple airbases, partially mitigating the risk posed by an enemy strike on any individual base, but those bases would also need the rest of the logistics chain.

With the sticker price just for tankers around $300 million each, building robustness is a very expensive proposition.

Operational Implications

If Australia is willing to invest heavily in more enablers like the KC-30A tanker, we could probably project airpower out to around 1,500 kilometres from one mainland base, but we probably couldn’t sustain a presence much beyond 1,000 km.

And, due to the number of aircraft the Royal Australian Air Force possesses, we could likely only do it in one place at a time.

If you’re a member of the school of strategic thought that believes the Australian Defence Force should be operating beyond our continent itself and out in the region, then this analysis shows how difficult it would be to provide air support for a deployed task force, for either air defence or close air support for troops engaged on the ground.

What this means is that if the RAAF devoted its entire effort to the task, deployed forces could hope for two F-35As providing sustained combat air patrols over Timor-Leste or mainland Papua New Guinea.

Sustaining airpower over Christmas Island (around 1,600 km from the nearest airbase) would be challenging, as it would over a near neighbour such as New Caledonia (1,500 km) or the planned joint naval base on Manus Island (1,300 km).

Sustaining any presence over key chokepoints such as the Sunda Strait (1,900 km) is probably not achievable.

Certainly, the task becomes easier if the commander is willing to accept more risk and if it’s decided that air support doesn’t have to continuous. But that means it may not be there when needed. And reaching relatively near neighbours like Fiji (2,700 km) can’t be done at all from mainland Australia.

Those who subscribe to the ‘defence of Australia’ school of strategic thought might argue that these scenarios are irrelevant because we shouldn’t be deploying task forces, particularly amphibious ones, in the first place. They would say our key missions will be either air defence of key mainland sites or strikes on bases our adversary is trying to establish in our near region or on maritime forces approaching Australia. They’d argue that with situational awareness and accurate predictions of the enemy’s movements, we should be able to fly missions only when we need to or at times of our choosing, and therefore we don’t need to keep aircraft constantly in the air a long way from their bases.

However, the problem with waiting behind a moat on the mainland was highlighted recently by Richard Dunley: ‘For the [defensive sea denial] strategy to work, the denying force needs to be stronger than its enemy everywhere (within the region of operations) all of the time. It’s no good being able to defend half of your coastline, or to do so whenever your forces are deployable.’

As explained earlier in the article, flying from mainland airbases to defend Australian cities, key infrastructure or potential enemy landing zones could still require ranges of well over 1,000 km.

Because of the size of our continent, conducting operations within Australia is essentially a form of expeditionary warfare that could require the same enablers as projecting power from Australia. From a pilot’s perspective, the Australian mainland is no different from the South Pacific—airbases are simply tiny islands in a vast brown continent rather than a blue one.

And, theoretically, you’d need to defend all of it all of the time. That means providing for the defence of Australia is at least as big a resource problem as the scenario outlined earlier.

If, however, we see the defence of Australia as essentially an anti-access/area-denial task aimed at striking the enemy as far from Australia as possible, the problem is somewhat different.

Conducting strike missions allows the commander to prioritise range over endurance.

If the commander is willing to take some risk (it is the defence of the homeland after all) and has a lot of tankers, they could push the range of the strike package out to 1,500 km.

A future F-35A-launched strike missile could potentially add around 500 km to that range, making the strike radius ring pretty big (see Figure 5).

2,000-kilometre range rings from northern Australian bases

It includes most of the island chain to our northeast and key choke points through the archipelago to our northwest.

But even in this role, the F-35A itself is just the tip of the iceberg.

The RAAF can assemble a potent strike force including Wedgetail early-warning aircraft for battlespace awareness and Growlers to jam enemy air-defence radars—and will soon have Peregrine aircraft to map the electronic warfare landscape.

But all of those assets are limited in number, so we could probably only conduct that task in one place at one time.

The most important element of a fifth-generation air force is highly capable intelligence, surveillance and reconnaissance assets.

For Australia that means the yet-to-be-deployed Triton long-range drones, the Jindalee over-the-horizon radar network, and space-based capabilities to locate the enemy far from our shores, as well as the ‘hidden’ targeting infrastructure necessary to support long-range strike capabilities.

Such a capability would complicate an adversary’s plans to establish forward operating bases or to conduct operations directly against Australia.

That means they’ll be doing everything possible to strike our airbases before our aircraft take off. Granted, if an adversary was using fighters, they would themselves face the same challenges we’ve been looking at.

But a major power would have a lot of other assets at its disposal, such as bombers, medium-range ballistic missiles, and submarine-launched cruise missiles, all of which outrange the F-35A. So, building a resilient strike system around that jet still requires the rest of the iceberg outlined earlier, including ground-based air defence and redundant fuel storage.

The starting point of this article was the concern that we will not be able to rely as heavily on US military power in the future and consequently we will need to be more self-reliant in some contingencies.

Using the example of air combat power, this series has argued that greater self-reliance requires not simply additional F-35As but a broad range of expensive enabling capabilities.

Even then there are critical points of failure.

Even if one assesses that a self-reliant defence-of-Australia scenario is an extremely remote possibility in any credible future and that the most likely task for the ADF is to continue to deploy in US-led coalitions, the problem of limited fighter range in the vast Indo-Pacific is a pervasive one.

There’s also the challenge that the US itself is grappling with of how to operate in the western Pacific when its fighters are substantially outranged by Chinese missiles.

That means the issues raised here are relevant not just for a defence-of-Australia situation.

Virtually any operations in the Indo-Pacific will face the same challenges.

Operating from Offshore Bases

While aerial refuelling can increase a fighter’s time on station, there are limits on how much it can increase range. Even with tanker support the maximum achievable range for the F-35A is between 1,000 and 1,500 kilometres.

Moreover, the number of F-35As that can be kept on station at those ranges is extremely small—sustaining just two fighters on station at 1,500 km would likely consume the Royal Australian Air Force’s current enabling capabilities.

One way to address these limitations would be to operate from airfields away from the Australian mainland.

But it can’t be just any airfield.

A minimum runway length of 8,000 feet, or almost 2.5 kilometres, is required to safely operate the F-35A.

A shorter runway could be used, but then ordnance or fuel may need to be sacrificed to reduce the take-off weight and, as we have seen, fuel is crucial.

In addition, lots of pavement is required for the aircraft to stand on while they are maintained, refuelled and armed. A 2002 RAND Corporation study determined that a squadron of fighters required around 12,000 square metres of ramp space. Runway and pavement size requirements increase substantially if large aircraft like tankers and early-warning aircraft are also operating from the base, as does the required pavement strength. There’s also the need for substantial fuel reserves.

Gaining access to existing military airbases helps, as at least some of those things are already available. The risk with foreign airbases, of course, is that access is always at the owner’s discretion.

Fortunately, Australia has a couple of airfields of its own that could help at Christmas Island and at the Cocos (Keeling) Islands.

The latter has an 8,000-foot runway that supports the P-3 Orion maritime patrol aircraft, which has recently retired from RAAF service.

According to Defence’s Integrated Investment Program, the runway is being upgraded to support the larger P-8A Poseidon maritime patrol aircraft. In June, Defence released a tender for works to strengthen and widen the runways, taxiways and aprons at an estimated cost of $200 million.

No improvements to support fighter operations appear to be planned.

1,500-kilometre range ring from the Cocos (Keeling) Islands

From the Cocos Islands, the F-35A could conduct strike operations in the vicinity of the strategic Sunda Strait between Java and Sumatra at its extreme range of 1,500 km, assuming it had access either to air-to-air refuellers (potentially operating out of a mainland base) and/or a long-range strike missile.

But maintaining a sustained presence would not be possible. Any operations over the Malacca Strait would be improbable, and they would be impossible over the South China Sea.

To project further north, Australia would need to rely on bases like Malaysia’s Butterworth that Australia has access to through an arrangement with the Malaysian government.

Butterworth puts the entire Strait of Malacca inside the F-35A’s unrefuelled range. It doesn’t get the F-35A very far into the South China Sea, although extending its range to 1,500 km through air-to-air refuelling would help.

Of course, in a contingency Malaysia might not feel that hosting Australian air combat operations was in its interests. The other big disadvantage is that Butterworth is within range of Chinese intermediate-range ballistic missiles.

2017 report by the US Center for a New American Security argued that such weapons have the ability to ‘devastate’ US forces in Asia and the Pacific as they are sufficiently precise to target runways, aircraft hardstands and fuel depots. Currently Australia has no ability to defeat such a threat.

1,000-kilometre range ring from Butterworth, Malaysia, and 3,000-kilometre range ring from Hainan, China

And there’s the rub.

The further north we operate, the further inside China’s anti-access/area-denial zone we get.

Of course, it’s hard to imagine a scenario where Australia would be operating so far from home without being part of a coalition with the US.

But even the US is facing the same challenge presented by Chinese capabilities—its fighters are out-ranged by Chinese missiles and its defences could be overwhelmed.

Airfields will be even more critical to any contingencies in the South Pacific. Just as operations in World War II in the Pacific were focused on gaining or denying access to airfields, so they will be in any future conflict.

But runways 8000 feet long are in short supply in the South Pacific. Those that do exist are international airports, not military airbases.

While the US military built many airfields across the region during the war, they were made for the aircraft of that time. Consequently, they are only 5,000–6,000 feet (1.5–1.8 km) in length and have very limited pavement. Many are in poor condition.

Manus Island in Papua New Guinea shows the potential advantages and disadvantages of offshore airbases in the South Pacific. Australia is currently working with PNG to upgradethe naval base at Lombrum on Manus.

There’s also an airport on Manus at Momote, originally established as a WWII airbase. As the figure below suggests, air combat operations from Momote would close the gap between PNG and the US forces based at Guam.

In a worst-case scenario in which US power in the western Pacific had been severely weakened and China sought to physically isolate Australia from the US (essentially a key element of Japanese strategy in WWII), airpower based at Momote could interdict any Chinese attempts to project force into the southwest Pacific.

If China does have intentions to establish military bases in countries like Vanuatu, Momote would in turn isolate them from China.

1,000-kilometre range ring from Manus Island, Papua New Guinea

However, the runway at Momote is only about 6,000 feet long. Upgrading air combat operations will take a lot of concrete for runway extensions and aprons as well as fuel and munitions storage, particularly if larger aircraft will be operating from there. If just strengthening and widening the Cocos runway is set to cost $200 million, upgrading Momote to support air combat operations will cost many times more.

While China has demonstrated its ability to lay a lot of concrete on islands quickly, it’s not something that the Australian Defence Force can do overnight. If it’s something we think is important, we’ll need to build it well in advance of any contingency. As with all offshore bases, partners’ interests and sensitivities need to be heeded at both the local and national levels.

Depending on the threat, many other assets would need to be deployed to protect the airbase, such as ground-based air defence and other land forces. This would bring Defence’s amphibious capabilities into play. Fuel may need to be delivered by the navy’s tankers. Protection and supply elements could need more F-35As and the navy’s major surface ships to protect them en route.

While offshore airbases could help project Australian power further forward, they would likely require substantial infrastructure investment well in advance of their military use and, potentially, the deployment of a substantial joint force to sustain and protect them.

Marcus Hellyer is ASPI’s senior analyst for defence economics and capability.

Featured Image is credited to the Australian Department of Defence

This article was published by ASPI in four parts which we have combined into a single article on Second Line of Defense.

Editor’s Note: This excellent article by Hellyer highlights the challenges of any tactical fighter and its range operating within a strictly national force. But the F-35 is not a traditional fighter and operates with reach not simply range because of its ability to operate with coalition F-35s to extend the reach of its combat information.

It is also clear that Australia needs to consider longer range strike assets as well as has been raised by the last two heads of the RAAF in a recent piece which appeared in The Australian.

As they argued in that piece:

“The force that we used to carry out nation-building in the Middle East cannot defend our sea lines of communication or prevent the lodgment of hostile power in the Indo-Pacific region,’’ Air Marshal Davies told The Australian. “But without a reset we will keep developing it against an outdated set of strategic circumstances.”

Air Marshal Brown, who led the RAAF from 2011 to 2015, called for a major increase in air power, saying that, as the strategic outlook changed, the air force, not the army, was likely to be the service of “first resort’’.

“As an advanced technological nation about to get deeply into space we should be playing to our strengths,’’ he told The Australian. “Investment in air crew and technology is actually incredibly efficient for a small nation with an educated population.”

The former air chiefs’ rare contributions to the debate come at a time of strategic upheaval, with the increasingly assertive role played by China forcing defence planners to rethink the country’s force posture.

And Hellyer’s focus on operating from forward bases, also raises the question of why Australia should consider adding F-35Bs to the fleet as well as operating F-35As but we will address these issues in a future article.