To be able.to shoot bullets at a pax aircraft you would reallistically need the aircraft to be at or below around 3000ft AGL. And even then you would have to be a pretty good shot. 3000 feet corresponds to around 9 miles on a 3 degree glide. Assuming the pilots level off for any ammount of time approx. 6 miles that means the IS guys would have to be within 15 miles of Baghdad airport, to take a realistic shot at the aircraft. The question is, are they that close? Any way I just made those numbers up I don't really remember the platform alts at baghdad.