The UK's F-35 situation

 

The reality of the announcement: it’s not the F-35A, it’s actually TRIDENT

At present, the F-35A announcement by the UK at the NATO Summit is easily translated and summarized:

 

Since F-35A procurement cost is somewhat lower than that of the F-35B and in theory we can more easily maintain it and have it available more of the time, we are procuring 12 of them instead, replacing as many F-35Bs assigned to 207 Squadron (Operational Conversion Unit). We will train our crews on the F-35A as far as possible, and only use F-35B for the unique parts of the syllabus. By releasing aircraft from 207 Sqn and by still procuring 15 new ones, we are still going ahead with standing up a third frontline Squadron.

Since F-35A comes Dual Capable, we are seeking integration into NATO Nuclear Sharing mission planning, carrying dual-key, US owned B61-12 bombs. We will presumably send a few of the F-35A to the relevant exercises a couple of times a year.

We are not spending a penny more than strictly needed as this is literally born as a Saving measure.  Forget about any UK tactical nuclear weapon, forget about storing the bombs in Marham (that would cost a lot in infrastructure) and forget about fixing the air to air refuelling problem.

Maria Eagle, asked during Urgent Question time in the House of Commons specifically on these points, confirmed that as “it is a NATO mission”: any UK F-35A long range mission will depend on allied tanker support. She also confirmed that "this decision is not a stepping stone" towards wider tactical nuclear plans. The UK is "not looking" at “broadening range of nuclear weapons and delivery means".

 

Scratch away the hype, dig to the facts, and while other countries announced new brigades, new SAM batteries, new jets, ships, etc, the UK really took to the stage to say: "we are saving some money off on jets for the OCU Sqn and, so long as you furnish us the bombs and air to air refueling, we can help carry a few of the warheads".

 

B61-12 launch trials. 

The only reason why Starmer wasn't laughed out of room at the NATO Summit while delivering such an announcement is that UK has a Strategic Deterrent of its own, which other double-key B61-carrying european partners don't have. In theory it puts a TRIDENT other than the US one behind the B61s.

As we know, after all, multiple NATO countries have F-35A to carry double-key B61-12s and had them before this UK stunt. They thankfully even have tankers which can actually air to air refuel said F-35A and anti-radar missiles & other weapons that give those F-35A wider capability and meaning.

Germany, Italy, Belgium, Netherlands and Turkey all have an established role in Nuclear Sharing and all but Turkey are acquiring F-35As for it, carrying American B61-12 bombs. Poland, which has 32 F-35A on order, has already expressed interest in being involved.

And of course, the US own F-35A Squadrons in Europe, and beyond, are available to carry the bombs as well. Most important for the UK perspective are of course the 2 USAF F-35A Squadrons in Lakenheath, which is where B61-12s could be stored on UK soil.

In practical terms, the 12 F-35A in theory added by the UK are almost entirely meaningless. They are few, don’t come with air to air refuelling of their own, and add to a vast fleet of potential carrying aircraft which would have no problems absorbing not only every last B61 stored in Europe but the entire stock of 200+, including the ones stored in Continental US (CONUS).

B61-12 bases. 

Inert B61-12 inside an F-35A's weapon bay. The F-35C's weapon bay has the same size but there was no B61 integration program because the US Navy has been out of the tactical nuke business since the early 2000s. 

More delivery aircraft are the very last thing needed. The one thing the UK adds here is actually TRIDENT. None of the other NATO countries depending on tactical B61-12 has a Strategic Nuclear Deterrent to loom behind the tactical warheads, apart of course from the US one.

Unlike France, the UK already declares its strategic deterrent to NATO, formally offering it to SACEUR, and by integrating in the Nuclear Sharing arrangement it is technically "supplying" a TRIDENT other than the American one to loom behind the B61s.

There is an argument to be made that the government announcement has been deliberately misleading on a political level: it's not so much the UK that is acquiring a new lever of deterrence; it is arguably supplying Trident to Europe. 

 

It’s tenuous, obviously, because the B61-12s are going nowhere without US authorizations and collaboration, and while the warheads on the UK TRIDENT are sovereign, the system as a whole does not stand without cooperation with Washington. But the political message is still valuable.

  

Value in a split fleet?

In pure money terms, the F-35A is effectively cheaper than the more complex F-35B and it’s also pretty realistic to expect its availability will be a bit higher on average.

There will be, as claimed, a short-term saving in terms of aircraft purchase, although the differences between the two aircraft and the need for a separate stock of spares etc will immediately eat away some of the savings.

The cost cutting measure will initially work, we can be reasonably sure of it.

Longer term, I’m pessimistic. Pain will inexorably pop up later whenever type-specific upgrade differences and material differences force duplications with their related costs.

It's also obvious F-35A as training jet can do most, yet not all the training of crews for the B fleet. 

 

When it comes to generating aircraft for operations, the two mini-fleets will generate their own entirely non-compatible pools of Force Elements At Readiness (the aircraft and crews actually ready to fly missions): the F-35A cannot contribute to carrier air at all; the F-35B cannot contribute to the nuclear mission.

 

The value of F-35A beyond the "training role with secondary nuclear mission" is very close to zero, if the number does not grow well above 12 over time and a number of other things aren’t funded and fixed.

 

The optimists are always quick to note that F-35A can fly a bit further on Internal Fuel and has weapon bays that are 14 inches longer than the B’s (no Lift Fan in the way) so can carry larger weapons internally. That makes them perfect for “Deep Strike”, is the usual justification offered.

However, that is only theory. In practice, the F-35A in the RAF will in fact not fly further than the F-35B. Whatever little advantage it brings in internal fuel range is completely drowned out by the RAF's inability to refuel them in flight, which Minister Maria Eagle already confirmed is not being fixed.  

As you should know, the RAF has access to up to 14 excellent A-330 MRTT tankers, the VOYAGERs, but none of them is fitted with Boom, which is what is needed to refuel USAF aircraft, including the F-35A.

The VOYAGER fleet is split in KC2 aircraft which have only the 2 drogues in pods under the wings; and KC3 aircraft which add a centreline drogue which enables the refuelling in flight of A400M.

 

A VOYAGER KC3 refueling an A400M with the centreline drogue 

The F-35A has a receptable on the spine and needs a Boom-equipped tanker to take on fuel in flight. The UK fields no such equipment. 

The centreline drogue is the one used to refuel the big receivers, which would in the past have included NIMROD (MRA4 and R1) and E-3D SENTRY. Unfortunately, over the years things have evolved the way we know and now the only big receiver left is A400M. P-8 replaced NIMROD MRA4 and needs a Boom, RIVET JOINT replaced R1 and needs a Boom (a special arrangement is in place with 100^th Wing USAF at Mildenhall to access their tankers so RIVET JOINT can go places) and E-7 replaced E-3. C-17 could also be air refuelled if the RAF had a Boom tanker.

 

In practice, the RAF literally has more platform types that it CANNOT refuel than ones it can. It's 4-3 right now (E-7, P-8, Rivet Joint, C-17 versus Typhoon, F-35B and A400). 5-3 with the F-35A.

The F-35A problem could also be fixed “laterally” by adding a probe onto it. Space reservation does exist in the fuselage, but it's the second poorest decision just above the current "doing nothing at all": it would make UK F-35As heavier and more expensive and, of course, all the strategic big receivers would remain unable to get fuel in flight.

Although the option exists, nobody took it. Those who have F-35A have Boom equipped tankers, and vice versa. 

Fitting probes rather than acquiring Booms would also mean the UK would continue to be severely limited in providing air to air refuelling support to Allies, which is not great when the 14 VOYAGERs represent a large percentage of the total number of tankers available in Europe and widely known to be insufficient.

 

There are glaringly obvious strategic reasons for acquiring Booms, the most obvious of which is the 143 F-35A in the "Nordic Air Force" (Norway, Finland, Denmark) that sits right between the UK and Russia. That powerful force is short of tanker support, and one of the best joined-up things the UK could possibly do was helping out with that by putting Booms on VOYAGERs to help THEM stay in the air and hit deep into Russia, while helping its own (and allied) P-8s to guard the North Atlantic and E-7s to deliver airborne early warning.

Instead, it is purchasing 12 F-35A that exacerbate the scarcity of tankers while bringing nothing tangible to the table.

 

The optimists assume that more F-35As will follow in the future. I’m not at all sure they will and I’ll explain exactly why, but if they do, expenditure to retrofit Booms on the VOYAGERs must be part of the plan.

 

Why am I so sceptical of the possibility of more F-35A Squadrons following?

Money, timelines, infrastructure, personnel.

 

What has been done right now is taking existing Tranche 2 procurement plans for 27 new F-35, which have been in the works since 2022, and split them into 12 A and 15 B, not adding a single extra jet.

Tranche 2 plans as known to spread the purchase and deliveries all the way to 2033 and at the moment we have been given no indication whatsoever of an acceleration.

In theory, in 2035 GCAP/TEMPEST will be entering service. Even assuming F-35 assembly lines will still be happily going by that date 2035, GCAP will be absolutely bleeding the budget dry.

It is not overly difficult to imagine GCAP not being ready by 2035, but that does not change the picture much: it will still be devouring a huge share of the budget, making it extremely difficult to imagine the RAF being still busy building up F-35 Squadrons by then.

 

Tranche 1 deliveries should conclude this year, in theory. The last of the first batch of 48 F-35Bs for the UK are coming out of Production Lot 17.

In theory, Tranche 2 buys could begin right away with Production Lot 18, the definitive contract for which is expected really soon. Lot 18 and 19, in fact, were due to have a combined contract award announcement this very month, so either it comes on Monday or it has slipped slightly.

 

Long Lead orders covering most of the material (and cost) for production lots 18 and 19 have been signed at various dates from December 2022 onwards.

The US DoD doesn't break down allocation of jets by country when announcing those orders and MoD/UK Gov in their usual mud-like clarity haven't provided info about when Tranche 2 starts.

 

At present we do not know for sure whether Lots 18 and 19 include any UK jet at all or whether there is a gap before new orders are placed. Tranche 1 ends with Lot 17 but it's not clear if T2 starts right away in Lot 18 or gap was/is expected.

We can only go by hints and clues: as funding for Tranche 2 was delegated to the RAF in early 2022 and the very first Long lead Items contract for Lot 18 was eventually awarded in December the same year, the assumption is that the UK is involved.

 

We do not yet know the full composition of the Lot 18 and 19 orders. Lot 18 Long Lead contracts were awarded in 2023 for a total of 147 jets, but the latest contract modification on 20 December 2024 only had 145.

In those 145 there was a single F-35B for “partner nations” and 7 F-35Bs for Foreign Military Sale nations. The 7 FMS ones should belong to Singapore and Japan, but the lone partner B is for the UK or for Italy? Given precedents, the 2 jets partly funded through earlier awards could be Italian ones, to re-emerge as contract modification later (it’s already happened in the past that timelines diverged somewhat), but we do not know.

So 0, 1, 2 jets for the UK...? We will have to see. Even if they were 2, that’s still clearly not a quick procurement pace at all.  

The exact same uncertainty exists for Lot 19 as well.

IF there are UK jets in lot 18 and 19, they are almost certainly going to be F-35Bs.

In fact, some significant Long Lead order has already been placed for Lot 20 as well, and if the UK funded anything in that, it will have been for B aircraft, again.

In practice, there are good chances that the first UK F-35A only happens in Lot 21, which roughly equates to order in 2027 and delivery in 2029.

Maria Eagle, speaking in the House of Commons, says the government is “hopeful” the first F-35A deliveries can happen “before the end of the decade”, which sounds like a confirmation of sorts.

 

It doesn't matter one bit how many times politicians insist on talking about 138 jets. Unless the next lots show a substantial acceleration in procurement rate, it's not going to happen. 

We have already been told, including by Chief Defence Staff himself, not to expect much for circa 2 years. Virtually nothing “new” is coming before 2027 at earliest, simply because no actual new money appears before then.

The only realistic hope of a greater F-35 fleet beyond 74 jets in 3 Sqns plus OCU lays in a drastic acceleration to the purchase rate beginning in FY2027. I don’t see how you can build any other Sqn otherwise.

The known plan of “27 jets by 2033” implies spreading the order across a minimum of 8 Lots, 18 to 25. Lot 25 would be ordered in 2031, and deliveries would wrap up in 2033.

If 2033 was actually the year of last order, we’d be looking at a spread across 10 Lots and last deliveries in 2035, indicatively. That means an average purchase rate of 3.3 jets a year in the best case, 2.7 in the worst.

In the kindest way possible: if the procurement rate stays at those levels, forget any fantasy of more Squadrons. You will be deep into GCAP funding era by then.

 

What if more Squadrons were to happen?

I want to make one thing clear: I have nothing against the F-35A in isolation. I know about the larger bays, I know about the greater range on internal fuel. You don’t need to tell me things that, respectfully, I’m likely to know better than you do.

The problem with a split buy from a UK point of view is that the number of jets and the number of Squadrons are not large enough to make a split buy sensible. The end result is a B fleet too small for what it has to do and an A fleet also too small to make any real difference.

 

3 frontline Squadrons are the complement of a single carrier, and they would only ever all deploy in a major emergency, of course.

3 Sqns are the size the JAGUAR fleet was withdrawn from service at. 2 Sqns is the size the HARRIER GR9 fate was sealed at. It’s not wise to have these numbers at the beginning of a long service life. Those are end of life numbers.

I do not think a split of 3 and 1 Sqns is in any way smart, period. 3 and 2 is also not very good. I’d rather have a single fleet type of 5 Sqns to generate force elements from, frankly. The individual characteristics of the airframe type are little more than a distraction when all other factors are considered.

 

Moreover, we have already seen this movie multiple times in UK defence history, and the end is always sour. Two fleets locked into fratricide battles each time there’s a need for concurrent but fleet-specific upgrades or other expenditure result in disasters. We have seen it again and again and again, most recently with SEA HARRIER and HARRIER GR7 and then with the contrast HARRIER versus TORNADO. To get into that position again for no good reason is absurd.

 

Any “deep strike” advantage F-35A brings is only theory, for the UK. It is only theory because if the Air to Air refuelling situation is not cured, F-35A will actually be far shorter legged in practical terms than F-35B. Nevermind the fact you can sail F-35B thousands of miles closer to whatever you need to hit.

 

The weapon bays advantage is also pure theory. At present there is not a single weapon, in service or planned, which fits the F-35A’s weapon bays but not the B’s. It either fits both, or is too large and fits none.

The F-35B could carry 1,000 lbs stores, but the UK does not have any bomb larger than the 500 lbs Paveway IV at this point.

Does it help anyone that F-35A could potentially carry 2,000 lbs stores?

No, unless new weapons are procured. There is nothing in the UK arsenal or existing plans that can take any benefit.

 

Also, any weapon integration process will be at least partially duplicated, to account for the differences between the two aircraft types. METEOR integration, for example: the UK is leading the F-35B process, with Italy leading for the A.  

There is a very real risk that the UK F-35A will have to partially repeat integration work (and expenditure) just to “port” Paveway IV and ASRAAM across from the B.

I have a suspicion, unconfirmed for now, that as long as the whole buy is 12 aircraft for the OCU, the UK won’t even try to get ASRAAM and Paveway IV cleared on the A.

Also, of course i suspect no ammunition will be procured for the 25 mm gun, considering gunpods for the B fleet have not been procured at all so far. 

 

The external "heavy load", innermost pylons are rathed for the same loads, so the F-35B should be able to carry Future Cruise and Anti-Ship Weapon externally, just like the F-35A. Internally, it won't fit either. AARGM ER, JSM, 2,000 lbs guided bombs could give a sense to the larger bays on the A, but none of these weapons is in the RAF arsenal nor in its plans. 
There might (or might not) be a possibility for the A to carry 6 rather than 4 Meteor internally, but we don't know. 

And there is yet another issue, in terms of infrastructure: RAF Marham has "obvious" room and Hardened Aircraft Shelters sufficient, with modernization work, for taking 4 Sqns. Project ANVIL fixed the South HAS area for the needs of 207 and 617 Sqns; the much delayed Phase 2 to finally go under contract next year is going to focus on the East HAS area to finally give 809 NAS adequate infrastructure and, hopefully, to prepare the space for the 3^rd frontline Sqn, which will also be the fourth Marham sqn (207 OCU, 617, 809 and the as yet unnamed Sqn to come).

Can Marham take more? Possibly, but without HAS (there are only 24 in total, each can take 2 jets once modernized) and with the need for further, substantial and expensive infrastructure work.

The alternative, even more expensive, is to activate another F-35 base.

 

Project ANVIL was heavily focused around the South HAS area. We expect the new contract to be centered on the East HAS area. The potential for squeezing more Sqns into the base to avoid activating another is unclear. 

In short, an expanded F-35A buy, in order to make even just one lick of sense, requires:

 

-         Not only buying more jets, but buying them much faster, to avoid going into "full conflict" with GCAP’s own funding needs just as they reach their peak

-         Adding Boom to VOYAGER

-         Procuring new weapon types, otherwise the larger weapon bays will mean absolutely nothing in practice

-         Infrastructure spending potentially including activation of a second operating base

 

Unless the Defence Investment Plan in Autumn has something serious to offer in regard to these needs, the infamous “138” F-35 number will almost certainly remain fantasy.

 

And in absence of Booms and adequate weapons, the F-35A is in fact of no substantial relevance for any “Deep Strike” mission you might try to imagine.

 

And that is if we completely ignore the wider issue of substantial duplication and inefficiencies that come from running 2 small fleets, and the risk of another fratricide relationship ending in tragedy a few years into the future.

 

None of the problems are impossible to solve. But for the specific UK situation, they are very unlikely to be solved, and that’s unfortunately what matters.