这是用于在flightgear的一个自建飞行器几何模型，只要放在相应目录即可使用。注意 这里面只包含了最核心的三个文件，而且工作在外部模式-This is used in flightgear a self-built aircraft geometry model, as long as it can be used on the appropriate directory. Note that there is only three files contain the core, and in the external mode