Turkish jets shoot down plane, page-34

"US official claims the aircraft's recorded heat signature proves it was not in Turkish airspace when hit by Turkish F-16 fighters."
http://news.sky.com/story/1593808/reports-russian-jet-shot-in-syrian-airspace

"Turkey's statement: Claims Russia violated airspace for just "17 seconds" with very slow 243 miles/hour jet. "
https://twitter.com/wikileaks

I think it's pretty clear Turkey is getting frustrated by Russia's effectiveness at disabling their ISIS friends.