ORAC,
Thanks for an interesting post. There are a couple of points arising from the statement from Col Kelly that I'd like to offer some thoughts on.
1. Apparently he said that: 'Conventional fixed-wing platforms are already more than capable of operating from a ship using a ski jump,..' I don't think they are. A conventional fixed wing aircraft can launch from a ski jump, but only at weights well below normal land based MTOWs. That's because the design basis for most ski jumps (to date) is that the STOVL aircraft they support can use their vectored lift systems to generate an optimal flight profile after ramp exit. They leave the ramp at BELOW flying speed, but at a high positive rate of climb generated by the ramp profile. After ramp exit rate of climb starts to fall, but is still positive. Because they're STOVL aircraft, they set their thrust vector independently of angle of attack to optimise acceleration while ensuring a positive (albeit falling) minimising rate of climb. As speed builds up, wing lift increases, and thrust is vectored further aft. At a known distance out from the ramp, the rate of climb stops falling and starts to increase again. This is known as the 'inflection point', and for a Sea Harrier it was about a kilometre out. Effectively, the ski jump has generated a 'runway in the sky'. This delivers a very significant increase in launch weight. The same happens with the F-35B.
Conventional aircraft can't do this. Their thrust vector is fixed relative to the aircraft axis and when they leave the ramp they have no option but to adopt a high angle of attack to generate as much wing lift as they can, and also get some lift from their (fixed) thrust system. However, that generates very high drag, so more thrust is needed to accelerate the aircraft. The result is a significant reduction in available takeoff weight. I know that some launches from the Chinese and Russian carriers involved the aircraft climbing then descending back towards the sea as they built up airspeed, before climbing away. Pilots tell me that's not an optimal situation. (I'm paraphrasing to remove the more agricultural language most of them used). The Chinese are working on catapult carriers for a reason. It's all about the physics.
2. He said that 'UAVs can be rail or vertically launched'. Well, yes, they can - the usual term is a 'catapult'. These are found on most aircraft carriers, but not on the QE class. Unless he's talking about some smaller system. He is undoubtedly aware that any vertical launch requires a very high thrust/weight ratio to enable the UAV to fly away carrying anything resembling an operational payload. Or a reduced payload. Again, it's all about the physics.
3. Lastly, he refers to the 'LANCA' concept being worked by Dstl and industry as a possible candidate to carry out AAR, weapons delivery, sonobuoy drops, EW missions and even AEW, all with a common outer mould line. Nothing I've seen to date on the LANCA concept looks remotely suited for any of these tasks, especially AAR which involves a hefty payload of fuel. The LANCA teams seem to be looking for a small, fast, smart, cheap air vehicle to accompany F-35s and Typhoons. If they are about one tenth the cost of an F-35, a reasonable first guess is that they would be one tenth the weight. That would make them about 6,000 pounds in weight. Even that would need a hefty catapult, especially if they have small wings for high speeds. The MQ-25 drone for the USN, with AAR as its (current) primary mission, weighs in at lots more than 6,000 points. So does the Kratos XQ-58, which seems to be the USAF's 'Loyal Wingman' concept, and they're not even remotely interesting in ship operations.
If the UK wants to develop a next generation of air systems to operate from the QE class ships, my suggestion (and that's all it is) is that they had better start developing a realistic and achievable set of requirements for them to do that, so that the design can be driven the right way. Going 'shopping' around the RAF's future systems concepts like Tempest and Mosquito (none of which appear to be remotely considering operating from ships) and hoping that they will be able to operate effectively from a ship is, in my opinion, a bit risky.
Best regards as ever to all those smart industry and Dstl people trying to work out what the MoD wants and how to get there,
Engines