|Possible layouts of Queen Elizabeth class carrier.|
The various options have different advantages, with CATOBAR using an angled deck and STOVL airplanes can be launched while others are being landed. With STOBAR that can't happen as planes that miss the arrestors will run through into those waiting to take off, with STOVL the landing points are aft of the start of the launch roll.
The advantages of catapult launched is an aircraft can be launched at full weight, so fully fuelled and fully armed, with short take off payload is lost but the aircraft carrier can be simpler as it doesn't need catapults. The next generation of carriers will use electrical system, know as EMALS, in place of the original steam powered catapults, which take less space and could possibly be fitted on to a ski-jump/ramp.
With vertical landing the complexity of the arrestor system is lost at the expense that the air-plane must carry the vertical flight system which is not of inconsiderable weight. This reduces the space for fuel and increases the total weight of the airframe, so you get a cheaper carrier at the expense of a fighter with less range and payload but with the added maintenance cost of the vertical flight system.
This could result in a radically smaller ship this would inevitably mean a smaller hangar deck and therefore a limited aircraft compliment, but might provide a better option than the strictly STOVL Sea Control Ship concept of the 1970s. With an August-Westland AW609 converted for AEW & COD this would would off increased capability over the SCS and could provide a UAV carrier and escort ship of outstanding performance for its size, possibly similar to the UXV version of the type 45.
One possible application of this could be to retrofit several EMALS to the Queen Elizabeth class carrier while upgrading the F35B to be catapult launched. This would be the best way of increasing the capability of the class at the lowest expense.