XPLMFindLastNavAidOfType
XPLM_API XPLMNavRef XPLMFindLastNavAidOfType(
XPLMNavType inType);
This routine returns the ref of the last navaid of the given type in the database or XPLM_NAV_NOT_FOUND if there are no navaids of that type in the database. You must pass exactly one navaid type to this routine.