For some reason, FSDT decided to display truck and bar as two different items.
The obvious reason for having the towbar separated from the truck, gives many benefits:
- There's no unnecessary duplication of polygons and textures, which would otherwise result if each pushback truck included its own copy of the same toolbar. This saves memory AND fps.
- We are allowing the simulator to eventually optimize the truck and the towbar separately, using object instancing, because it can sense the same toolbar is used many times, so it will only load one copy of it in memory, because IT IS a separate object. Instead, if it was included in each truck model, they would be seen as different, so the simulator would waste memory AND fps to load many times something that might have been loaded only once.
- Some trucks are used (as in real life) in more than one context. For example, the same Tug M1A can be used to Tow an airplane, but also as the front truck of a Baggage loading train. By having the vehicle and the Towbar separated, we don't have to create two completely different models of the same truck, with or without a towbar, but only two variations, which are easier on memory and disk space, and are easier to keep updated separately.