This is a decent example, but it's not quite comparable to developing general AI. We can build helicopters without a full conceptual understanding of aerodynamics, but we can't produce a physical simulation which will accurately determine which helicopter designs will and will not fly for any given design without a full understanding of aerodynamics under the conditions in which helicopters operate.
Creating aerodynamics simulation is creating an aerodynamic system. Creating a general intelligence is creating an intelligent system. A better analog to creating a helicopter using incomplete understanding of aerodynamics is something like creating a system that can discriminate between what is and isn't a general intelligence. We don't have such a system, but it at least doesn't seem like the sort of thing that would require a full understanding of intelligence.
That seems at best totally unrelated? You've asserted that general AI is some sort of different category than other things which we can and have built without understanding the fundamentals of their operation. But you haven't actually provided any real evidence of that.
The Wright brothers basically mimicked nature and tested till they got it right. They didn't use Bernoulli's equation to create a NACA airfoil and L/D max calculations. [2].
To that end, in one of my undergraduate Aeronautics classes, when we were doing a bunch of Bernoulli equations someone calculated that based on that approach helicopters couldn't actually fly. To which our instructor said, "Oh yea, helicopters fly by magic."
[1]https://secretofflight.wordpress.com/incorrect-theories/ [2]https://wright.nasa.gov/overview.htm