The Kurds aren’t mincing words:
http://kurdishdailynews.org/2015/11/27/turkey-suspends-syria-flights-due-to-fear-of-retaliation-by-russia/
Turkey suspends Syria flights due to fear of retaliation by Russia
“Kurdish forces controlling Kurdish region in northern Syria warned Turkey not to violate its airspace and promised response in case of breaching of Kurdish airspace.”