Couple of points to throw into the -B vs -C debate in an attempt to add some balance:
The UK don't have a requirement or any intention, as far as I know, to buy 2000lb JDAMs. The only bomb we're talking about putting in the bays is the mighty Paveway IV, which fits comfortably in both the -B and the -C. Granted, the bomb will have more room to wiggle its fins in a -C, but that doesn't necessarily mean the -C is 'more capable' than a -B. If both aircraft go to war with the same load out of PWIV and with identical avionics, the only differentiator from the UK's standpoint really is the range.
People often mention the STOVL weight penalty i.e. having to cart around a lift fan etc. Take a look at the empty weights of the variants anywhere online (e.g.
Lockheed Martin F-35 Lightning II - Wikipedia, the free encyclopedia) and you may notice that the weight penalty for a CATOBAR aircraft is actually higher than that for a STOVL. So, the empty weight of a -C is higher than a -B, it is a bigger aircraft so must have more zero lift drag, and it humps around more fuel. But it has the same engine & thrust. Leaving aside requirements documents and the like, how does aircraft handling normally vary when aircraft get bigger and heavier but have the same thrust?
Through-life costs are anyone's guess. The STOVL lift system doesn't come cheap, but because STOVL is so ridiculously easy in the F-35B you really won't need to practise it very much at all. But landing F-18s on ships takes oodles of practice and the F-35C approach speed is higher than a Super Bug and the skill needed is not fundamentally different. So the training burden, and associated fatigue life & maintenance burden of the -C won't be free. We just won't know until 20 years from now, but I wouldn't bet my mortgage either way at the moment. For a decade the smart people doing all their TEPIDOIL analysis figured the -B was cheaper through life. Did they cook the books for 10 years and we had a moment of clarity at SDSR? Or did they get it right over the last decade and did someone fiddle the numbers on one occasion?
Finally, that range number... Is there a genuine specific requirement for our F-35s to go 600nm instead of 450nm? For the last couple of decades the GR1/GR4 brothers have been the untouchable long-range deep strikers of the RAF. Can one of the experts out there tell me what the actual realistic combat radius (not the Top Trumps answer) of a GR1 was in its design/intended first-day-of-the-war loadout e.g. with the JP233s on, or a stick of 8x1000lb KFFs? Just curious, because 450nm sounds like a long way to an old Harrier mate and a pretty reasonable capability.
Personally I've always wondered why we never went for the mixed fleet of -Bs and -As option like the Italians.
Regards all,
Single Seat, Single Engine, The Only Way To Fly