What is the F-35B and Why is the UK Buying It?

By Rich Wordsworth on at

Over the past few years, the F-35 Lightning II – the fifth-generation, Lockheed Martin wunder-plane set to eventually take over from almost every fighter jet in the US and UK militaries – has received a public relations kicking. It’s expensive – the total cost for the programme so far is an incredible, not-even-hyperbolic trillion dollars. It’s had some embarrassing technical stumbles – engine fires, a non-functioning cannon and a half-million dollar helmet that fits comfortably in the cockpit or on a pilot’s head (but reportedly not both). And while it’s designed as a multirole, do-everything plane that will see the West through the next three decades of air combat, critics have been queuing up at the online pulpit to explain why it’s not as capable in each mission role as the plane it’s supposed to be retiring. Though they’re usually not that polite about it.

But despite the media bellyaching, the UK is committed to purchasing an as-yet unknown number of F-35s, primarily to fly off its two new aircraft carriers. Committed to the tune of about £5 billion (so far), which covers the first 14 UK F-35s and their maintenance up to 2020 (but not the larger bulk purchase expected in 2017, which would bring the UK’s F-35 fleet up to the stated 2020 target of 48 planes). The final total, however, is likely to be much higher.

That’s a lot of zeroes to spend on something that critics claim doesn’t work. So why are we doing it? How do the criticisms hold up? And what does the F-35 mean for the UK in particular?

Image credit: Flickr/Lockheed Martin

What Sort of Plane Do We Need?

The uncertainty about the sorts of missions the RAF and the Navy will have to fly in the future is what makes a multirole aircraft so appealing. Compared to the US, Britain is in no position to buy a fleet of specialised aircraft – between 1990 and 2014, we reduced our number of operational fast jets by more than two thirds, with smaller numbers of Typhoons and Tornados stretching to take up the slack. Of the two, the Tornados are the pressing concern – they were introduced in 1979, and the ones we still have flying are due for retirement in 2019. If we want to keep getting involved in overseas air campaigns, we need something to take their place.

The F-35 is the only so-called ‘fifth-generation’ fighter being produced in the West. The choice, then, was either to buy into the F-35, or to look for planes similar in capability to the Typhoon. The promise that makes the F-35 such an appealing purchase (at least on paper), however, is that it can do everything: air support, bombing runs, air-to-air combat – three planes for the price of one.

That’s a contentious claim, so let’s look at these roles in turn.

Image credit: Flickr/Lockheed Martin

Supporting Ground Troops

The UK doesn’t have a dedicated plane for close air support. While the US has the purpose-built monster that is the A-10 Thunderbolt, the UK’s manned air support duties have been divvied up largely between the Tornados, Typhoons and the Apache helicopters. The F-35 claims to have one clear advantage over all three in this role.

“The big advantage that the F-35 gives you is its stealth,” says Philip Sabin, professor of strategic studies in the War Studies department of King’s College London, and an expert in air power.

“With both air-to-ground and air-to-air, the idea is that it will not be safe for fourth generation aircraft – or even really heavily armoured things like the A-10 – to operate in the future. They’ve done it in the past, in a fairly permissive environment against Cold War era air defence threats… and of course they’re more efficient in that case, because if no-one’s shooting back effectively, then it’s a wholly asymmetric contest.”

In addition to not being shot down, the three key elements in the close air support mission are ordnance, loiter time (the amount of time a plane can hang around looking for and engaging targets before it has to refuel), and the ability to reliably spot those targets from the air.

The bad news is that the F-35Bs that the UK will purchase – one of the three models that are being produced – is the least capable at the first two of those. The F-35B is the model designed for short take-off and vertical landing (STOVL) – if you’ve seen a picture of an F-35 hovering, that’s the B model you were looking at. Without catapults to fling planes off the end of aircraft carriers and catch them when they land (which Britain’s new Queen Elizabeth class carriers don’t have), this is the only way to get planes into the air and to get them back again.

The problem is the extra hardware that goes into the B variant to make STOVL possible. Not only does the engine have to tilt down 90 degrees, but to balance the lift (and provide more of it), the F-35B has to incorporate a giant fan in the front half of the plane that pushes air downwards. The fan doesn’t have a use outside of take-off and landing, which means while the F-35B is flying, it’s lugging around that extra weight to no benefit.

But the fan is also taking up space in the body of the plane which the other two non-STOVL variants (the F-35A and F-35C) can use for other things. As a result, the F-35B has to use a smaller fuel tank, limiting range and loiter, but also has less space for ordnance. The B’s internal weapons bays, tucked into the body to maintain its stealth profile, are limited to two 1000-pound bombs and two air-to-air missiles, while the A and C variants can carry bombs that are twice that size. To cap it all, all that extra gadgetry also makes the B variant the most expensive option of the three.

The good news is that all that isn’t the death knell that some opponents of the F-35 would have you believe. For one thing, modern fighters (including the F-35) aren’t necessarily restricted to burning what they can take up in their tanks.

“The big limitation of the B is in endurance,” Sabin says.

“We’re seeing very clearly in the current operation over Iraq… the difficulty of having to operate at range. Also, if we’re effectively in a reactive environment where air[craft] have to loiter, not just deliver the weapons at the time of its choosing, then the F-35 is going to have problems in that regard.

“[But it’s not] like the old days, where it was just a matter of ‘how far can you get an aircraft,” he clarifies. “Air-to-air refuelling has changed that, and it’s so routine, now.”

Image credit: Flickr/Lockheed Martin

Long-Range Bombing

As for the F-35B’s limited payload, that’s only a factor for as long as you prize stealth over firepower. The F-35 is adaptable – if what you want is more bombs, you can hang extra ones from pylons under the wings. Doing so, however, compromises the F-35’s stealth capability – but if the mission is to hit targets that aren’t protected by aircraft or anti-air defences, that’s not necessarily something you have to worry about.

As for ‘only’ carrying two bombs, Sabin argues it’s a concern that’s been overblown.

“[People] talk about, ‘oh, it can only carry a couple of bombs,’ [but] we don’t usually drop more than that,” he says.

“We usually drop less than that, in a sortie. If the limitations are that you don’t want to release the bombs until you’re sure of the target, and you don’t want to put your pilot in any peril at all, then those are the things which are going to constrain you, rather than, ‘oh, we haven’t got ten 2000lb bombs to plaster the enemy with.’”

The two bombs that a stealthy F-35 can carry are also only half the story of a bombing mission. Not only is an F-35 doing so-called ‘deep interdiction’ (hitting things deep inside enemy territory) hard to see, its weapon bays also hold two air-to-air missiles, which means it has some ability to take care of itself as it sneaks about in enemy airspace. Two missiles doesn’t sound like a lot, but this brings us neatly to one of the other great promises of the F-35: that it can identify and destroy other planes before they get close to visual range. If the system works as advertised (and that is definitely still an ‘if’), then defending pilots are looking for a plane that can’t be reliably tracked on radar, that won’t let them get close enough to see it, but can see and engage them just fine.

Image credit: Flickr/Lockheed Martin

Fighting Other Planes

That’s the third role that the F-35 is supposed to fill: air-to-air combat, replacing specialised fighters like the F-16. This is the area in which, recently, the F-35 has received the biggest credibility body blow – down to a leaked report from an F-35 pilot who was pitted against an F-16 for a simulated dogfight. The results were, on the surface, pretty bleak: the F-35 pilot’s report was that the fifth-generation fighter simply didn’t have the power or the manoeuvrability to take on a nimble, dedicated fighter like the F-16 at close range and survive.

That’s not the sort of result you want when you’re pitching the F-35 as, among other things, the F-16’s successor. But again, there’s an argument to be made that the test isn’t a good measure of the F-35’s abilities. Yes, the F-35 might perform poorly in a Top Gun-style contest – but the idea is that the F-35 should never allow itself to get into that situation in the first place.

“Results of mock combat can be interpreted in different ways,” says Sabin.

“And the answer there seems to have a lot to do with how far [an expected encounter will be] a dogfight – a traditional turning, manoeuvring dogfight – as opposed to long-ranged engagement with smart missiles, where you don’t even get into the fight at all, [and] the enemy doesn’t know you’re there until it’s too late and they’re being blown out of the sky.

“That’s the area where, arguably, the F-35 excels, because it can get its missiles in the air without the F-35 needing to illuminate the target with its own radar and put the enemy in danger before the enemy can get any kind of lock on the F-35. So in this kind of classical, head-on engagement, there are major advantages to the F-35. Certainly over non-stealthy aircraft, like the [Russian] Sukhois for example.

“Certainly if you set [an F-16 and an F-35] against each other, and they’re turning round to go off on each other’s tails, I’m not surprised the F-16 did pretty well – especially in daylight. But, in other circumstances, in perhaps more realistic circumstances of networked warfare, rather than artificial one-on-one tactical duels, it may well be another thing altogether.”

Image credit: Flickr/Lockheed Martin

But Does Stealth Really Work?

Critics of the F-35 like to bring up the F-117 ‘stealth fighter’ shot down over then-Yugoslavia during the 1999 NATO bombing campaign. How could a relatively under-developed force shoot down a stealth aircraft if stealth is as effective as the military and the defence contractors say it is? And if stealth doesn’t work, why are sacrificing so much in pursuit of it?

“Stealth is not a magical shield,” says Sabin.

“[The F-117 case] shows that it’s not invulnerable. What it does, is that it complicates the task of the opposing air defence. It’s all very well saying, ‘in certain circumstances, we could think of ways in which to defeat the stealth.’ The current situation is that opponents find it difficult to use their air defences to effectively fight even fourth generation aircraft. Moving beyond that and being able to target effectively a stealth aircraft [is even more difficult].”

The stealth criticism also assumes that, on a given operation, the F-35s are the only planes Britain will have in the air. But that needn’t be the case. One strategy that Sabin identifies for the F-35 is the same as was used by the US in the 1991 bombing of Baghdad during the first Gulf War, in which the F-117s were sent in ahead of a larger bombing force to soften up the Iraqi air defences. In the case of the RAF and the Navy, the equivalent would be sending in F-35s with their two-bomb payload and electronic warfare capabilities, destroying and jamming an enemy’s air defences, and then rolling in with heavily-armed Typhoons. It also assumes that, in this hypothetical air campaign, Britain is fighting without the support of its allies – something it hasn’t done since the Falklands.

Then there’s the practical question of whether we would risk pilots on missions without stealth.

“[Whether stealth is worthwhile] depends how you feel when you’re sitting in the plane and your life’s at risk,” says Sabin. “We know how sensitive Western nations are to any loss of their own pilots. Any risk of that may well lead to the operation not being conducted at all. Stealth can give you at least some… not insurance, but reason to think that it’s not as dangerous as it would be if you were going in with just Typhoons.”

Image credit: Flickr/Lockheed Martin

This All Sounds Expensive...

It will be – although the UK government won’t say exactly how much the first bulk order of planes will cost, or what it’s expecting the lifetime operating cost to be for each aircraft. You’ll also get a different cost estimate for every person you ask – though Defence Secretary Phillip Hammond (who seems like a good source) did say in 2013 that the first 48 UK F-35s would cost around £100m each. Of course, that could go up or down in the four or five years between now and the first UK delivery date of 2019/20.

So, the programme will be pricey, which has two negative effects on the planes themselves: numbers and value.

“They just cost so much,” says Sabin.

“And that therefore reinforces the problem which the Royal Air Force in particular has, [which is] the lack of combat mass. Once the Tornados go, we are going to have a very small number of combat [jets]. They’re going to be very precious, [and] they’re going to be really hard-pressed if we need to take part in any kind of serious, attritional air campaign. That’s the biggest problem.”

However, the high cost of the F-35 does come with one, tiny silver lining. It means that any creases in the plane’s design – the cannon, the fires, the helmet – really, really have to get ironed as soon as possible. Too much money and time have been spent now to let bugs like these shoot the F-35 project down.

“One great asset that the F-35 has is that it’s almost too big to fail,” Sabin concludes.

“So many nations now are in the programme, and the numbers of aircraft overall are so significant… that they’re going to have to solve these problems – or it’s going to be an absolute catastrophe for the future of Western aerospace power.”

Philip Sabin is a professor of strategic studies in the War Studies department of King’s College London with a specialisation in air power. He has held research fellowships at Harvard University and the International Institute for Strategic Studies, and is a consultant for the Ministry of Defence.