I see that this started back in the day before computers and simulations, but it all comes down to integration testing. I've seen plenty of instances where all

I see that this started back in the day before computers and simulations, but it all comes down to integration testing. I've seen plenty of instances where all the parts worked in testing but in the real world it failed miserably. It is ingenious that they figured out to just mount the planes upside-down on a short test stand as a way to do the testing so there wouldn't be the interference of the pole in the way. I am willing to bet they had a time where they thought about hanging the planes from a giant crane or maybe actually fly the plane over a huge track where the test equipment was on a train following the plane.