I clicked reply during the time you wrote your own reply I guess. The fact that going up a slope with a jet-engine is preferred is all due to costs. Jet-engines

I clicked reply during the time you wrote your own reply I guess. The fact that going up a slope with a jet-engine is preferred is all due to costs. Jet-engines are just cheaper to operate (and easier to supply with fuel). Perhaps more energy is required in total; but this energy is released in a much cheaper way.