Jet Below

Yesterday we drove to Boston, and deplaned from Logan Airport for Vienna, with a long layover in Paris. I took this shot of a plane below us, looking south at 14:45, about 35 minutes before our plane from Paris landed in Vienna. So it was certainly over Austria, with higher mountains close by. (I'll mark it on the map, but it's obviously a guess.)

View it large for a better look. The narrow black shadow on the plane's right wing must be from the tail. It doesn't look like a passenger jet to me--any comments?

Viennese blips start tomorrow :)