[Video] Huh? Stock B-52 wings appear to sag initially

[acf492]

Hi,

I'm pretty sure that airframes don't flex in YSFlight. Yet, I just joined a server and saw the wings of my stock B-52 appear to sag in the first few seconds after joining. This is repeatable. So, umm, what?

Is this new, or something? I'm running YSFlight for Linux, 64-bit, GL1.0 And I loaded her with 100% fuel, which might explain this in the real world -- but that doesn't cause new game physics to spontaneously happen.

Any ideas?

[Neocon]

Parts can change position with speed (wings on the F-14, for example), so it's really easy to make the wings appear to flex by making them in sections as child models that slowly turn around the point they connect to the previous section. There are several models that have taken advantage of this. I'm pretty sure it's been possible since the early days of YSF.

[Turbofan]

Yeah, back when I started playing YSFS in '01, the stock B-52's wings did flex as the plane started gaining speed. So that feature has been around since then for sure.

It's the Variable Geometry Wing or VGW parameter that you see in the data file (.dat). That's "coupled" with the part/s in question of the model itself in the dynamic model file (.dnm). I don't know the inner workings of all of this but you basically specify the VGW V1 speed (when the dynamic part/s start getting animated) and the VGW V2 speed (when the animation's complete).

It's also been used for animating the landing gear tilting (CHF's 777s) and a few other parts other than wings.

The reason the wings sag or the landing gear moves "into position" when you initially spawn with an aircraft that has such workings is that the dynamically moveble parts have a delay when the aircraft spawns.