PPRuNe Forums - View Single Post - No cats and flaps ...... back to F35B?
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Old 9th Jun 2012, 13:12
  #1041 (permalink)  
Engines
 
Join Date: Dec 2006
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Milo,

The article in 'Sharkey's world' is accurate - but then I would say that as I contributed the technical piece for it at his request.

I stand by my assessment on Typhoon and STOBAR - the launch issue revolves around how fast it can accelerate (with a heavy payload), how fast it can enter the ramp, and then how slowly it can fly away. Without vectored thrust (and that thrust operating throughout the CG) flying a Typhoon away from the ramp would be an interesting exercise. It really needs a reaction control system (which BAE proposed), and that would take more thrust from the already hard worked engines. At any realistic combat payload, a Typhoon launch would require very high end speeds. I'm not at all sure it can get there in a short deck roll.

The recovery issue is just as demanding - how do you get the aircraft to fly a good 30 to 40 its slower than a normal runway landing, catch the wire and then stop? BAE's ideas involved sprung decks and RB211s to generate an artificial upwind, as they knew that getting the necessary landing gear strength for a normal 'trap' would severely compromise the airframe. Trying to catch a wire flying some sort of 'dynamic false' manoeuvre is, in my view, a non-starter. And we haven't even mentioned the structure needed for the all new hook system. Typhoon is a very weight sensitive aircraft, as it should be to achieve its shatteringly good air to air performance.

I would think that any 'Sea Gripen' would encounter the same issues.

LO, very hard to answer your question without adding a lot of detailed assumptions about launch methods and performance calculations that I can't do without data. However, I would take a hefty bet that even from the same land runway, F-35A, B or C would all outperform Typhoon or Gripen in a strike role. That's because the F-35 is optimised to perform in the strike role - internal weapons bays deliver a massive range boost, and it has a very large fuel fraction. All its sensors (like EOTS) are already built in. Typhoon has to carry all that stuff (fuel, weapons, pods) externally. Typhoon is optimised for the air combat role, and very well optimised too - but that large wing and high thrust to weight ratio degrade performance in the strike role.

I spent a few years on the T-45 Goshawk programme, and that experience of modifying a very good light training aircraft to operate from a ship does, I admit, colour my opinion.

This issue has been around the buoy a number of times now, always happy to respond, though. In short, if you want a world beating land based air to air combat aircraft, buy Typhoon. If you want a ship based strike aircraft, don't.

Hope this helps,

Engines
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