Microsoft never intended to have animated people on the tarmac.
Well, yes and no. They haven't supplied anything like that themselves (but there are several human characters as library objects in the default scenery), but they put the basic foundation to make it possible, and it was there since FSX was released.
It's a little bit tricky to define if we are running within the FSX engine or not. Surely, the basics are entirely provided by FSX, if it didn't supported animations with bones and vertex shaders, it would have been close to impossible to make such kind of characters. However, the FSX engine is made with many parts, which sometimes are intended for other uses, and are not really cooperating well between APIs. There's Simconnect, which is the "official " API, there's the XML gauge interface and the C gauges interface, and there's the scenery engine.
We used both official methods and reverse engineering as well, to get access to all of these, and used Python as a "glue" script engine, so once we got access, we don't have to worry in which language or how the original interface worked, but it's all wrapped in an easy to use language, which allows us to do very complex things, that FSX normally doesn't provide. For example, we don't have any limitation on the complexity/length of the animations, we don't have to loop them if we don't want to, we can have triggers, conditions, variable evaluations, control playback speed and direction, and interaction with any variable in the FSX engine.
As I've tried to explain in my previous post, once we tested that human animations were theoretically possible (this was almost a couple of years ago), we haven't just dive in and started to animate stuff just to have something to show, but rather went to lay down the foundation to do something useful first, since the technology is just too good to be wasted on just scenery decoration.
