branch = "/instrumentation/" + _name;
SGPropertyNode *n = fgGetNode(branch.c_str(), _num, true);
_serviceableN = n->getNode("serviceable", true);
branch = "/instrumentation/" + _name;
SGPropertyNode *n = fgGetNode(branch.c_str(), _num, true);
_serviceableN = n->getNode("serviceable", true);