US Marine Fighter Attack Squadron 121, which began flying its F-35B jets to the air station in January, now has a full complement of 16 aircraft.

The squadron — which five years ago became the first in the US Marine Corps to receive the jets — also became the first forward-deployed F-35 squadron when it moved to Iwakuni from US Marine Corps Air Station Yuma.

This comes as the 13th F-35B for the United Kingdom was recently delivered by Lockheed Martin.

It is believed that 138 F-35 aircraft will have been delivered by the 2030s. Around 2023, the Ministry of Defence have indicated that the UK will have 42 F-35 aircraft with 24 available as ‘front-line fighters’ and the remaining 18 will be used for training (at least 4-5 on the OCU), be in reserve or in maintenance.

Numbers right now are exactly where they’re expected to be and inline with the 2015 Strategic Defence and Security Review.

2 F-35B in LRIP run 3, 1 F-35B in LRIP run 4, 1 F-35B in LRIP run 7, 4 F-35B in LRIP run 8, 6 F-35B in LRIP run 9, 3 F-35B in LRIP run 10, 2 F-35B in LRIP run 11, 2 F-35B in LRIP run 12 6 F-35B in LRIP run 13, 8 F-35B in LRIP run 14 and 7 F-35B in LRIP run 15. This brings us to 42 in 2023.

The next year and next run brings us to the total of the first batch of aircraft, 48.


  1. 16 is for me the optimal size of a squadron as it gives 4 flights of 4 with the ability to have a self sustaining unit that can ensure a minimum of 8 airframes are available at any point in time.

    For the carriers 2 Sqdn of 16 is optimal – not the 24 that HMG would like us to believe. Put simply there would be 4 aircraft at immediate readiness, 4 at high readiness/training, 4 in std maintenance and 4 in deep maintenance.

    Not sure how many aircraft are available out of an RAF sqdn of 12 at any point of time, but this seems to be more logical to me.

    • ‘maintenance’ to be covered by the ‘remaining 18’ according to this article and earlier releases. I assume that does mean ‘Deep maintenance’ with airframes rolling into the 12 as other aurframes role out of the 12 .

  2. These are new aircraft. Not sure how much deep maintenance they will need initially.
    Other threads on this site indicate the F35 airframe is very tough and has withstood extensive continuous testing.
    My biggest concern is the RAF putting a deliberate stumbling block into the RN and carrier operations by demanding a switch to the A variant of the F35 when we should be keeping the faith and continue as planned.
    optimal numbers should be 96 F35Bs in active service so that we can operate both carriers if needed at a surge capacity of 36-48 aircraft.
    if RAF gets its way with the A variant we will have just shot ourselves in the foot. Limited our carrier strike, increased our costs of maintenance servicing and spare parts by having 2 types of aircraft with very differing capabilities and engines.
    RAF need to be told to stop their self grandeur and concentrate on what is right FOR THE NATION.

    • The RAF doesn’t need the B variant, the A is cheaper to buy and maintain plus you need 50% fewer A’s to complete many combat missions than a B (that’s munitions on enemy targets).

      The economics and military effectiveness of buying a mix of A and B variants far out weigh the arguement that we have purchased two large carriers and need to buy aircraft to fill them up.

    • Agreed that they are new and deep maintenance should not be required, but organisationally the Air force (and navy and army) should be prepared to rotate its assets (which includes people) through different levels of readiness. My view is that this will not only be cost efficient but will ensure retention of service as forces personnel can plan their family life better.

      A period of deep maintenance would align with non deployed duties, training and return to family as often as possible and if cycled accordingly this would mean that people spend at least 1 Xmas away from home in every 4 (maximum). So my view on this isn’t just equipment it is personnel who also need to be cycled through varying states of readiness for their own protection and welfare as well.

      This does of course mean that the UK can only deploy circa 25k personnel to active duties at any one time + a carrier group, but for me that is what we are funding – so that is the figure.

    • Hi Mister B, Beyond the requirement for 48 aircraft; other than perhaps to top-up for attrition, I see no great reason for the UK to invest further in the F-35B version; no doubt, it’s a superb aircraft – but it’s STOVL flexibility does come at the cost of some performance penalties, particularly in range.
      The “big-wing” A version is a much better fit for operations in which the RAF is likely to be involved. (Moving forward, you can also see a scenario developing where the FAA will take over all the STOVL aircraft).
      I’m a big fan of our new QE class carriers, and hot-footed it over to Fife to see Queen Elizabeth on the same day it was floated out of the Rosyth basin! Carriers give great flexibility to our combat power, but it’s also worth remembering that they are only a means to-an-end: – deploying air-power in the support of British interests. The UK has myriad alliances, overseas bases, and agile diplomats, and has been able to do that successfully from land-bases since the Falklands conflict of 1982 – and even did so during the recent Libyan campaign.
      We need to strike a balance in our air-power resources between operations from land – and the sea. Evidence suggests, despite the QE class, UK air-power will still largely be deployed from air-bases in Europe, and elsewhere.
      As always, good to debate with you.
      (BTW: Thanks for your other post about casualty figures, dropped you a reply on that other thread)

      • Whilst accepting that the A variant is indeed the best I think the RAF have typhoon to provide the legs and reach that you are talking about and I do believe we need to standardise our fleet as much as possible.

        If we replace our Typhoons with F35A’s then I am fine with that, but given our relatively small fleet size (138 total against a 400+ operational fleet for the USMC alone) then I can’t see the sense in purchasing another variant, its just a level of complexity that is not needed unless the numbers go up (which they won’t).

        Its far to point out that this is capability regeneration and if you look at the Tornado and Harrier fleets at point when this capability was removed you are looking at an operational fleet of circa 200 aircraft. So even if the UK purchased 138 as its operational fleet (which I believe it should) we are still massively down on required numbers.

        72 Harriers sold to USMC in 2011 and 124 Tornado’s (as of today)

        So yet another stealth defence cut. The current lifetime order of 138 F35b should be an order to regenerate the FAA with a fleet of 72 airframes (4 sqdns of 16 + 8 ).

        Where is the order to replace Tornado – answer it isn’t there and thats why the RAF are talking about cannibalising the F35b order.

        Time to be brave and put in an order for the next 2 blocks of 24 per block and get us back on track. I mean its not as if the MOD dont know these fleets are becoming obsolete is it.

        • how is it that the u.k ,the only level 1 partner in the f 35, programme has to wait while the f 35b is given to japan before us? is the u.k asking why? i doubt it aircraft carriers with no aircraft , the t 26 beginning 5 years later than planned, the type 31 being designed on the back of a fag packet, plus the ocean, supposedly surplus and being sold, is on duty as a FLAGship on a nato exercise.oh i nearly forgot a 6 ship class of the worlds leading class of destroyer breaking down all over the planet., honestly i doubt half a dozen rivers are going to deter mr. putin and his merry men. its a shambles. i;d love to see the panic in whitehall if her maj said she’d like to review the fleet!!

  3. The aircraft may be physically tough, but the software needs constant updating and maintenance.

    It’s that software that makes the F35 the fantastic aircraft it is, but that advantage comes at a cost in terms of availability of aircraft when the aircraft is relatively immature in software terms.

    • but the united states of paranoia don’t trust its biggest customer with it because we can’t be trusted. the u.k still has time to cancel the f 35 order rafaels and gripens are built in half the time of a f 35 cancel 2 f 35’s to fund CATOBAR on the carriers.this would save hundreds of millions of£ and give america a well overdue middle finger. but lets face it the u.k doesn’t have the balls to do it.

  4. Morning all
    To sustain carrier operations the U.K. needs a minimum of 4 F-35B Sqns (12 a/c). This means just over 100 a/c will be required.
    Of all the variants of F-35 the B model is the most complex and therefore most expensive per platform. Cost however should be measured in overall capability. Our CVF platform cost ROM £3bn each and for that we get a carrier that if required could happily host 36 F-35B.
    US Ford carrier at over $10bn is somewhat out of our reach but it provides the US a platform where they can launch slightly cheaper F-35C.
    Cost per flying hour I would suggest is quite close between the two, HMG just cannot afford the $10bn upfront cost of a 102000 tonne aircraft carrier.
    Now the political bit.
    In 2010 it was decided to withdraw the Harrier fleet as the RAF convinced the government that the Tornado provided better value. Whether the argument was right or wrong I am pretty sure has been healthily debated here and elsewhere. For some this was seen as the RAF returning to their 1970’s maxim that air power only deployed from land bases controlled by the RAF was they way forward and the RN should stick to chasing subs in the North Atlantic covered from the air by the RAF.
    Some believe that the RAF are at it again, trying to undermine the RN and splitting the purchase of the F-35.
    Whilst simpathetic to that argument one would hope that the RAF are looking at the role that they are being asked to fulfill and seeing that the F-35A satisfies that better than the shorter legged B model, that whilst a good aircraft, has made compromises in range and carry to get it off a shorter runway (Aircraft Carrier for example).
    As the Tornado reaches the end of its life we have to remember what it was designed for (Interdiction and Strike). The ability to get as close the centres of gravity as possible drop its weapons and get safety out again. Typhoon will do well in that role, F-35 has been designed from the ground up to do it better.
    The RAF want the best platform available to make sure they carry out the missions assigned. Why wouldn’t they want the A model.
    So what to do and how many do they need? And what are they willing to sacrifice to get it?
    Tornado end of life is 2019. Tranche 1 Typhoons will not be long after that. If the split buy is to happen it will need to happen soon to fit in to the “lot” cycle. How many, at least 3 a/c Sqn’s to be credible (36 a/c) so at least 72 frames to sustain that.
    This would total a U.K. buy of circa 172 F-35.
    Someone, somewhere will have to sacrifice something to pay for that. All eyes back on the RN and RAF

  5. Couldn’t agree more with you Lee and I will go further. We should really be ordering 300 F35b’s as realistically there is nothing else out there that is as good for the next 20 years.

    I do have a bit of an issue with people accepting tactical capability gaps and then being unwilling to pay the cost of regeneration. If we are getting rid of something totally then that needs to be said up front.

    An F35 order of the magnitude of 300 will pay for itself over the next 25 years and by standardising on a single platform (albeit 2 variants) – but in greater volume we should become far more efficient and effective.

    It is a difficult one this as the Typhoon is a great aircraft but with 25 years to spread this over it will be end of life by the time the final F35’s are coming off the production line.

    Food for thought – but just like the NSS – we also need an integrated fleet and industrial strategy for land and air asset allocation and production.

    Basic fleet management set against a defined set of strategic goals

  6. Hi Pacman27

    Basic fleet management set against a defined set of strategic goals – used by successful multi-national companies all over the world.
    Unfortunately this is government we are talking about here. They have no vision, therefore lacking the definition of a mission so therefore executing low level tactical options satisfying industry needs and sustaining their seats in Parliament.
    May have sounded a bit negative there…..

    • Sadly I agree with you and it is one of the primary reasons why we spend more on maintenance than equipment.

      Time to change that and god knows the industrial base could do with the orders. We need to commit to a set of basic numbers of everything each year and just build.

      1 Escort (T31)
      0.5 Escort (T26)
      0.5 Submarine
      0.75 Fleet Aux (inc amphibious)

      6 – Fighters (F35A) = 150 Total Order/Fleet
      6 – Fighters (F35B) = 150 Total Order/Fleet
      12 – UAV (Taranis) = 300 Total Order/ Fleet
      1 – Transport = 25 Total Order
      1 – ISTAR 25 Total Order
      12 – Medium Helo (Merlin/Osprey?) = 300 Total Order
      6 – Attack Helo’s (Apache?) = 180 Total Order
      4 – Heavy Lift Helo (Chinook) = 100 Total Order

      And for the Army …

      400 – JLTV = 10000
      800 – Polaris = 20000 over 25 years
      200 – Warrior/Ajax = Total Order of 5000
      25 – Tanks (= 1000)
      400 – Heavy Duty vehicles = 10000

      anyway you get the drift – we can keep a number of factories and the British industrial base going with these orders and rationalise the parts and engines as opportunities arise. Seems to me we just need to sort out basic fleet management and then constantly evolve designs over the lifetime – say a major design change every 5 years to stay current and keep the designers busy.

      I could see the factory in Wales doing the majority of this – and it may not be as efficient as purchasing several thousand at once – but that is also part of the problem by the time we leave it the numbers are just so big that they become unpalatable. Constant updating and refresh is the way to go.


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