Question;
if a PLANAF J-15 (which is a conventional aircraft) can take off from a ski jump carrier with an empty weight of 18t and a max. weight of 33t - then why couldn't an F-35 A/B/C take off from a ski jump?
They can. And the B and C do for the Brits. The J-15 Carrier version is also beefed up in airframe and landing gear like the F-18 and F-35C is. The F-35B lands a bit different and doesn't need the arresting equipment although it can use them. The F-35A is built for land based and has the best thrust to weight ratio and can take off heavier than either the B or the C using a ski jump. You just can't land the A back on the carrier more than a couple of times before you just shove it off the end of the carrier as junk.