In hindsight, the critical technologies for powered flight were aerodynamics and internal combustion engines, and flying became easy - at least compared to the prior 0.000% success rate - once those were sufficiently advanced.

It'd be very interesting to know how the brighter engineers viewed things at the time. It had been known for millennia that birds and kites could soar, and there must have been some sort of "Moore's Law" awareness that IC engine power/weight ratios were rapidly improving.